Working with Image Templates

Now that we have worked with all the impor tant tools and managers we can go on to more complex objects

So as not to waste space with already ex plained techniques I will assume that the tools and functions discussed previously are by now familiar

As subjects for our next modeling exam ples I have chosen a sports car and a charac ter/figure The techniques to be shown are transferable to other objects as well

You will see that the majority of the work can be done with a few functions

Ultimately the important part is the most efficient way of placing points Generally it should be a light mesh which means a model with the least possible number of polygons and points

In order to keep in sight the shape that is supposed to be modeled templates are used during the modeling process These are mostly photos or sketches that can be shown in the viewports We will use this technique when we model the figure

We will use yet another way of showing image templates when complex models are to be built With this method images or sketches are used to create spline curves at the most important contours This might sound a bit complicated because of the time it takes to create these splines

Especially for organic objects with complex curvature this method has the advantage of providing a threedimensional frame of the shape that will be modeled The frame of the object is then created and only needs to be filled with polygons

We can start with loading the image tem plates in the B

side of the E

C

dialog of the editor viewports (see Figure ) Ideally we have a front side and top

view image These will then be loaded into

the appropriate editor viewports

In order to be able to work with these images in the editor they need to have the same scale and to be adjusted according to size in the viewports

My images have different sizes as shown in Figure

The scaling though will be quite simple be cause the images are reduced to the area be tween roof and wheels Therefore only the S

Y value has to be transferred to the C

settings of the other images The X value of the size will be adjusted au

tomatically as the K

A

R

is acti vated by default

This procedure can be seen in the upper im age of Figure There the Y S

value was copied from the front viewport to the side viewport The proportion of the two images is now correct

We can also use the O

values in the C

menu to move the image templates to any place in the viewports This is especially important when an additional top view image is loaded

These images have to fit to each other so that a point placed at the headlight in the side view will also be placed at the headlight in the other two viewports

After the images are loaded resized and placed correctly it is time to create several splines to trace the contours of the car Interest ing here is the area where component groups meet and also distinctive creases and edges

The best way of creating the spline is to fin ish it in one viewport and then adjust and cor rect it in the other An example is shown in Figure

The more carefully the splines are placed the easier and more exact the following mod eling will be

Because this is more of a chore than a chal lenging technical exercise I have already cre ated the splines for you and placed them in a scene on the DVD of this book (see Figure ) There you will find several intermediate states of the modeling process so that you can start this workshop at any point

I myself used blueprints and photos for the creation of the splines These I cannot give to you because of copyright reasons

It is easy enough though to find these kinds of images and drawings on the Internet For example at wwwsuurlandcom there is an abundance of uptodate blueprints of cars boats and even airplanes

The vehicle that I chose for the modeling is a Smart Roadster which I could not find as a D model on the Internet yet Therefore the effort is worthwhile

We start our modeling with the fender of the car It is necessary to model only onehalf of the car as all parts will be mirrored later on

Start with a new scene and load the splines from the DVD Then create a P

object in the O

menu (see Figure ) It will serve as a container for the points and faces

Switch to

mode and select S

C

P

Click on the four cor ner points of the first polygon that we want to create in the front viewport Double click on the last point to create the polygon In this manner create several polygons then switch to the

tool In the

tool setting activate the D snapping to splines and snap all edge points to the splines Points that do not have another point near by have to be moved by hand to the appropriate position

Continue this technique until the upper edge of the fender is evenly covered with poly gons (see Figure )

Do not create too many polygons and points at once or you may lose the overview Try to use as few polygons as possible

Keep in mind that we have to round and smooth the model later with the help of a H

NURBS object In this way create polygon strip after poly

gon strip along the fender and finally down be hind the wheelhouse as shown in Figures and

Try to bridge the gaps with polygons as large as possible This will make you feel more secure in the beginning process of modeling the shape

The faces between the splines can be subdi vided with cuts later

When like in this case (see Figure ) cuts have to continue around a corner we use S

A

P

and create new points directly on the existing edges or even in the middle of faces

The reason for the sort of cut shown in Fig ure is to () gain more control over the cur vature of the front part of the fender and () raise the point density in the front of the fender where the headlights will start

After the points have been created convert the newly created NG

faces into rectangu lar polygons This will give us more control over the path of the edges and the result of the rounding with H

NURBS objects

Use the F

R

N

to convert the NG

faces The result can be seen in Figure

As we can see at the path of the new edges some new triangles were created that we will have to remove manually Therefore delete these polygons and create new faces between the existing corner points with the B

or C

P

tool The result can be seen in Figure

At the right edge of the fender starts a slightly tilted hard edge that will continue up to the end of the door This edge would need to be created by a few parallel edges They should be close enough to each other so that the H

NURBS smoothing will work later on Therefore I moved a row of points closer to

the crease as shown in the lower images of Figure

The effect can be seen instantly when the

object is grouped for a moment under the H

NURBS object (see Figure )

I have already added an additional cut above the edge as you can see in Figure and even more clearly in Figure

The K

tool can be used here as this cut follows the polygon loop

Remember to move instantly newly created points to their right position or else areas will be created where all the points are positioned in a twodimensional plane This would result in a suboptimal result at the H

NURBS smoothing

We already talked about the shape change of the upper part of the fender where the headlight will be attached

We will add a vertical cut like the one shown in Figure in order to have an exact enough shape change after applying the H

NURBS This section can be seen very well in the

view from above where the fender recedes laterally

Make sure to snap new points which were created by the subdivision to the splines

whenever possible This does not happen auto matically so these points need to be moved by hand This is another reason why you should work in small steps and create faces only where they are really needed

However cutting back on faces should not go so far as to result in cuts that are restricted to single polygons Basically it is always better to create an evenly subdivided mesh that con tains as many rectangular polygons as possible for the smoothing later on

We also use the additional points to further finetune the crease at the right edge of the fender as shown in Figure

Surely you have noticed the extremely rounded corners at the edge of the object when the model was smoothed by the H

NURBS object Generally the extreme rounding is a desired

effect but we need exact fitting edges in the upper area and to the right where the door component and front part of the trunk meet

We need to support the edge area with ad ditional cuts so that the H

NURBS does not have enough space to round the edges Therefore use the K

tool in L

mode without creating NG

Both cuts are high lighted in Figure

Make the cuts as close as possible to the outer edge of the shape This will strengthen the corners in the H

NURBS These areas are marked by red arrows in Figure

We will rearrange the two faces marked in Figure so that the already modeled crease in the fender does not run toward the wheel house

Delete the faces and create two new poly gons as shown in the center of Figure As a result the crease deviates in an arc to the up per area and ends in the smoothed version in a soft line parallel to the wheelhouse

The distance to the edge of the wheelhouse needs to be bridged with a polygon strip but the points do not need to be created by hand

Just select all edges in the area and use the E

command for duplicating and moving the edges However the next step of snapping the new points to the spline has to be done manually (see Figure )

Figure shows how the faces on the right of the wheelhouse can be extended downward to complete the right part of the fender

The contour of the wheelhouse is one of the distinctive parts of the model that needs to be shown as a visible edge Therefore we will add a new edge loop with a K

cut in L

mode This is shown in Figure

The fender turns into a slim strip in the front In order to model a clean transition we have to make sure that there is the appropriate or der of faces

Use the A

P

function in the S

menu again and place new points on the vertical edge in front Figure shows these points in red

After the conversion of the created NG

with the R

N

function arrange the faces as shown in the bottom of Figure

Remember to use all new points to shape the model and to snap the points to the splines A possible result can be seen in Figure The model slowly takes shape

If your model does not look so smooth it could be that a

object was not auto matically created with the P

tag Just add this tag with the T

CINEMA D T

P

menu in the O

M

A narrowing of the polygon strip needs to

be done at the same time as there is a sharp tapering of the front shape of the fender

Add a few new horizontal loop cuts to the front part of the fender to aid the transition to a small area

Then use the E

function at the left front edges (see Figure )

A triangular face should have been created after the new points were snapped to or placed along the splines (see arrows in Figure )

Make a K

loop cut downward starting from the lower edge of this triangular face

The triangular face now has an additional point and can be closed with a rectangular

polygon The result can be seen in the lower part of Figure

Extrude the edges in the lower area of the front the same way to transform the shape in one step to the profile of the front bar (see Figure )

Additional vertical cuts will allow us to ad just the edge areas at the splines

When creating new cuts be sure that as many areas as possible are closed by rectan gular polygons between the old and new

faces The finished transition could look like Figure

Also note here how the edges are pulled to gether in order to create a hard edge in the middle of the front bar

This part is almost done because the profile will not change anymore Therefore the outer edges can be extruded to the middle of the car in one step The result can be seen in the top image of Figure

If we want to be precise then the gap be tween the fender and the front bar has to be created too It looks as if the two components were put together at that spot This kind of gap can be added easily

Select the vertical edges at the place where the gap should be produced The corner points are marked in red in Figure

Use the B

command to duplicate the selected edges and to move them away from each other in a parallel manner

Select the polygons located between the two new edges and use the E

tool to re cess them into the model The result is shown in the lower image in Figure

Create a S

object and subordinate the model to it Set the symmetry plane to YZ and activate the merging of points at the sym metry plane

Check if the points of the front bar are ex actly in the middle on the symmetry plane and

then subordinate the S

object under the H

NURBS object Figure shows the mirrored object prior

to smoothing and the same scene with the ac tive H

NURBS object Note that by melting the front bar points in

the middle a nice curvature is created in the bar We therefore do not need to add addi tional subdivisions

Next we will create the illusion of wall thickness Make a loop selection of the contin uous edges Use the E

function to dou ble these edges and move them simulta neously to the edge faces (see Figure )

The direction of the move can be controlled exactly by the angle value in the E

dia log This component is now completely done and we can go on to the next one

We will continue with the front headlights and front bumper These parts are made with

the same material which creates the illusion that they are one unit Therefore we will build this component group as one model

It is always difficult to integrate exact openings into an object afterward For this reason we will start with the shaft of the headlight and continue from there with the rest of the component group

Let us close both splines which represent the front edges of the headlights with an E

NURBS object (see Figure )

All M

values of the NURBS object should be set to a value of as we do not need movement of the splines Furthermore we need only one cap Deactivate the end func tion for caps and be sure that the cap is closed by rectangular splines

The H

option needs to be active when both splines are subordinated under the E

NURBS object All necessary options are shown again in Figure

Now convert the E

NURBS object and change into point mode since we will con tinue with polygons

Use the CREATE POLYGON tool to close the gap between the filledin ellipses with poly gons

Then change into edge mode and select the continuous edges of the upper ellipse face that do not yet have a connection to the lower el lipse Extrude these edges a little bit outward Figure shows this step in the second im age from the top

Back in point mode move the newly cre ated points farther outward and snap these to the spline with D snapping Repeat these steps with the edge of the lower ellipse as is also shown in Figure

Finally create the transition faces so that a closed area is created around the headlight The result is shown in the uppermost image of Figure

Figure also shows how the original faces of the headlight shafts are selected again and extruded inward a little bit A small poly gon circle has been created around the shafts of the headlights

Extrude these polygons forward a bit This will create a small beaded rim around the headlight shafts as seen on the bottom of Fig ure

Now the actual shafts can be created by ex truding the faces inside the beaded rims (see Figure )

Do this in two steps First extrude the faces only a little bit and then extrude them to the desired depth This additionally sharpens the shape at the front edge of the shafts when the HYPERNURBS smoothing is calculated

The length of the shafts is not important as they will be closed in by the headlight glass in the front part

A continuous cut has to be added as shown in the bottom image of Figure because the transition between the headlight shafts and the outer edge of the component group will be shaped as a gentle curve

The best way to do this is to select the nec essary edges and then use the EDGE CUT tool

After that use the newly created points for continuous molding of the headlights The ar row in Figure points to the desired bend of the shape Figure also shows how to con tinue with the lower edge of the model

Select the continuous edges in the lower area of the object and extrude them a short dis tance Then in another step bring them up to the middle of the upper bumper

Now the upper bumper can be created quickly by a few new extrusions The result can be seen in the upper image of Figure All points can be comfortably snapped to the splines

Create a onepolygonwide strip going downward at the right edge of the bumper This will be its lower border and is also docu mented in Figure

The basic form is now completed and now we can extrude the continuous edges verti cally to give the object more volume (see Fig ure )

Finally delete the faces that create the back walls of the headlights so that open ended pipes are created This saves us a few polygons

The polygons in the “mouth” of the bumper will also be extruded a bit

Be sure to have a large border angle so that a coherent extrusion is formed This creates a new parallel edge loop around the mouth opening which lets the edge look sharper in the HYPERNURBS smoothing

After subordinating this new object under the HYPERNURBS and the SYMMETRY objects it might look like Figure

Then check if all the points along the left edge of the object are placed exactly on the plane of the symmetry object and if both ob

jects (fender and headlights) lie snug against each other

On the outside of the opening in the bumper there is a combined unit with integrated turn signal and fog light We will model their hous ing next

We can save a lot of work by separating a few faces directly from the inner area of the mouth opening as this housing will be placed exactly at the shape of the bumper

Therefore switch to POLYGON mode and se lect the inner faces on the right side of the mouth opening Use the FUNCTIONSSPLIT to double these faces and to copy them into a new object These faces are recognizable in the upper image of Figure

In this image a red arrow already points to the next step as the left side of the separated faces will be closed by a single polygon You can use the CREATE POLYGON tool for this step

Add two horizontal cuts to the manually created polygon so that the edges will be pre served when the component is sorted under the HYPERNURBS object These cuts are high lighted in Figure

Finally use the CLOSE POLYGON HOLE com mand in the STRUCTURE menu to close the front face of the object

Use EXTRUDE INNER with this new face to create a small polygon ring around it This will keep the front of the object smooth even with activated HYPERNURBS smoothing as shown in the lower image in Figure

The gap between the just created turn signal lights will be closed by a stylized grille We will now build the frame of this grille We can start with existing faces here

Use the SPLIT command for the inner faces on top and bottom of the opening as well as for the faces that form the left border of the turn signal housing (see Figure )

With FUNCTIONSCONNECT connect the new objects to each other to form one object The original objects with the separated faces can then be deleted

Add a few KNIFE cuts to subordinate the corners as the faces on the right side do not blend seamlessly into each other

The upper right corner is highlighted in red as an example for the newly created points in Figure

The overlapping faces can now be deleted Create new connection faces so that a continu ous frame is built The new faces are shown with arrows in Figure

Now select all faces of the object and ex trude them (with the activated CREATE CAPS option) further into the opening Make sure that the MAXIMUM ANGLE value is adjusted so that all faces will be extruded together The desired result is shown in Figure

Then select the front faces as shown in Fig ure and extrude them inward a short dis tance The finished smoothed image is also shown in Figure

The motor is in the back as is common with sports cars Therefore under the trunk lid which we will now model there is only a small storage compartment

A simple plane is already very close to the shape of the trunk lid Create a PLANE object and set it to segments in the X direction It should be aligned parallel to the floor

Convert the plane to a POLYGON object and let the points of the plane snap with D snap ping onto the splines The end result is shown in Figure

Three cuts have to be added as the trunk lid has a curvature at the outside and is not straight This can be done very well with the KNIFE tool in LOOP mode These three cuts marked with arrows can be seen in Figure

Thicken the continuous edges by extruding them like we did before after the shape of the trunk lid is adjusted by moving the points As a result the trunk lid looks like it has volume

Check if all points are lying in the middle at the symmetry axis The finished lid is also shown in Figure

Let us get to the bar that frames the wind shield The basic form can already be framed by two spline curves

You can take either the premade splines or create your own

A polygon skin is formed when the splines are subordinated under a LOFT NURBS object (see Figure )

Make sure that the LOFT NURBS object has a sufficient number of subdivisions The bar will be smoothed and subdivided later by the HYPERNURBS object and should not be divided too much

I think a MESH SUBDIVISION U of is suffi cient for the LOFT NURBS object

The object just needs some volume and then we will already be done with this part

Convert the LOFT NURBS to a POLYGON ob ject and use the EXTRUDE function with the ac tivated CREATE CAPS function to create the thickness of the bar Thicken the bar toward the inside of the car The outer measurement is determined by the splines and should not be changed

Remove faces located in the symmetry plane and set all point coordinates there to the X position of as this shape will be mirrored with the SYMMETRY object and thus be merged at the symmetry plane

The position of the face which needs to be deleted at the thickened bar is marked by the mouse pointer in Figure Figure also shows an image of the finished bar as it will look when the SYMMETRY object is smoothed by the HYPERNURBS object

The short crease in the rear part of the fender also continues over the entire length of the door Therefore the easiest way to start the door is to use the profile of the fender

Select the polygons at the side of the rear fender These faces are marked in red in Fig ure

Separate these faces with the SPLIT com mand in the FUNCTIONS menu in order to get a new object

Extrude the front edges of these separated faces and then pull them in the direction of the spline that borders the right side of the door The end result can be seen in Figure

We will leave a little gap between the moved points and the spline as Figure shows

Add a cut at the lower part of the door as the amount of points is not enough to form the curvature of the door The course of the cut is shown in Figure by the red line

The previously mentioned gap up to the right spline will now be bridged by another edge extrusion Only the edges marked in green in Figure will be extruded together

By closing the resulting gap on the bottom right with a polygon the door is framed on the bottom and right with a polygon strip This will improve the edge sharpness tremen dously after the HYPERNURBS smoothing The result is shown in the two upper images of Figure

Now we will give the door some volume as we have done before with other parts There fore extrude the edges on top bottom and to the right Spare the upper right edge of the door because here is where a door handle will be later on

Due to the left side of the door having been thickened we will get double points

The procedure in these cases is demon strated in the series of images in Figure with a simple example object

For a simple demonstration I rebuilt the door in a stylized shape (see Figure )

In the uppermost image the start condi tion of the door is shown which has the thick ening only on the left side

After the extrusion of the edges which are marked red we get double points and edges on the left side of the object These points are marked in red and moved a little bit on pur pose to show them better

Activate the STITCH AND SEW command in the STRUCTURE menu in order to combine these points to only one

Two points can be combined by pulling the mouse from one to the other when this com mand is active First only a connection line is shown which is also displayed in Figure After releasing the mouse the point that was clicked first will snap to the second point

An automatic optimizing is executed that leaves us with only one of the two points Fi nally the finished door is shown in Figure

Next to the fender starts the supporting struc ture of the car which is extended under the door to the right and upward The upper part forms another bar This structure can be devel

oped out of two splines similar to the front bar (see Figure )

We will use even fewer subdivisions in the U direction I used nine subdivisions in the U and three in the V direction in the LOFT NURBS object

This time we have to convert the LOFT NURBS object as we will add additional cuts and model the shape more exactly in the lower part

My extra cuts are shown in red in Figure

Because the crease of the fender and door is also visible in the bar adjust the position of the edges accordingly

The part of the bar that is at the fender does not just stop there but disappears behind the car body Thus bring this end of the bar far enough under the fender

The lower image of Figure shows the desired shape of the bar There the bar has a fold that runs parallel to the crease in the door

Now only the typical HYPERNURBS round ing of the edges at the lower end of the bar needs to be addressed

In EDGE mode the outer edges could be se lected with a RING SELECTION and be parted with EDGE CUT or we can use the KNIFE tool in LOOP mode

The new edges should run close to the outer edge of the bar Figure shows this in an example with arrows and in the middle with red marks

Then thickening of the shape is followed by the extruding of the outer edges

As before the faces have to be deleted that are on the symmetry axis

The thickening of the shape can be seen marked by arrows in the lowest image of Fig ure

A look at the created objects shows that the car is slowly taking shape (see Figure )

As with all complex modeling jobs the split into small component groups and the model

ing of one part after the other yields in the end a very good result

Also the number of tools and functions used can be reduced to a minimum as you might have noticed So far we have modeled almost all parts with only the EXTRUDE and KNIFE tools

We will continue with the rear of the car This shape rises around the wheel housing There fore it makes sense to start with the edge of the housing and to work outward from there

This shape can start out with a basic DISC object Because this object offers the possibil

ity to determine an inner radius as well as a slice it can be used to model the edge of the wheel housing without much effort (see Fig ure )

Subsequently we need to convert the ob ject because the points of the bent polygon strips have to be snapped precisely to the splines Furthermore new polygons will have to be created at the edges of this object

Add a new face to the right edge of the con verted polygons and lead them along the tem plate spline around the wheel housing up to the rear apron

Create two additional cuts so this area can be rounded three dimensionally as shown in the bottom image of Figure This is done quickly with the EDGE CUT function as the de sired number of cuts can be specified there

Bridge the distance to the next help spline with another polygon row Figure shows these polygons in red

These faces do not have to be made by hand Just extrude the outer edges of the ex isting shape move them and let their points snap via D snapping at the spline

Figure also shows in the bottom im age how the polygons can be created up to the small strip above the hood

Bridge the gap to the rear roll bar and the upper template spline with a new polygon strip Figure shows this marked in color

Note the ellipseshaped opening between the bar and the rear apron This is the area for the lateral air ducts which we will close later with a grid

Because the area above the wheel housing of the original car has a round shape we need to create more edges by selecting them with the RING SELECTION and parting the edges two times with the EDGE CUT tool The result is shown in Figure The cut edges are marked in red

Use the new points to create a bulge above the wheel housing Note that this bulge has to be reduced at the left and right sides In prac tice it should look like Figure

The arrows mark the two distinctive edges of the components At this point we should be working with the HYPERNURBS object to smooth the object in order to better evaluate the effect when moving the points

Remember to deactivate the snapping when the points should not snap to the splines

As with most of the components a con tinuous subdivision has to be added close to the outer edge so that important corners are not smoothed too much by the HYPERNURBS object

We can use the KNIFE tool in LOOP mode When the line of the cuts is not as we envi sioned it is possible to move the new points onto the edges with STRUCTURESLIDE Figure shows in red how the path of the new edges should be

As with all component groups use the EX TRUDE function for all continuous edges to simulate a volume of the component

After subordinating the rear apron under a SYMMETRY object and a HYPERNURBS object the result could look like Figure

The upper part of the rear consists of a tail gate and a side window These windows are (from the perspective of a modeler) very dif

ficult because these faces have relatively complex curvature

For modeling we have two template splines at our disposal I was able to create these be cause the edge of the window had another color making it possible for me to trace it with a spline

We start the modeling process with a PLANE basic object which has three subdivi sions along the height and five in width (see Figure )

It is not recommended to start with many subdivisions as every point has to be moved manually and partially placed without the aid of the spline snapping

Align the plane so that it is parallel to the innermost template spline and convert the PLANE object

Use the D snapping to splines to place the corner points of the plane onto the spline Concentrate the points in the corner of the splines as shown in Figure

Next add an encompassing polygon ring by extruding the outer edges The result is shown in the first image of Figure Additional cuts can be seen in the following images of Figure

Because we want to keep the subdivisions of the inner part of the object to a minimum it is better to create local subdivisions This means not cutting through the whole structure This is often possible with EXTRUDE INNER as is shown in the bottom image of Figure

Faces in the edge area then have to be de leted and open points need to be snapped to the splines

Additional points can be used to form the wedgeshaped right part of the window This will need special care because of the curvature in this area The described steps after the inner extruding are combined in a series of images shown in Figure

Even with the most careful placement of points in the window it is almost impossible to create a perfectly rounded surface For this reason we will use the IRON tool in the STRUC TURE menu (see Figure )

Figure demonstrates the mode of ac tion of the IRON tool on a wrinkled plane As Figure shows this tool smooths out irreg ularities The strength of the effect is deter mined by way of the PERCENT VALUE

I recommend working with small PERCENT AGE values and using the tool multiple times until the desired smoothness is achieved

The IRON tool can also be restricted to se lections This will be helpful as the edge points of the window should remain snapped to the spline

Thus select only the inner points of the window as shown in the upper image of Fig ure Then use the IRON tool to reduce the irregularities of the surface

Add the familiar subdivisions close to the outer edge to sharpen the profile with the HYPERNURBS smoothing

We need to model this object as a volume this time as it will get a transparent material Only then will the REFRACTION value of the transparency work realistically

Therefore switch to polygon mode and use the EXTRUDE function with the active CREATE CAPS option to thicken the object Extrude it toward the inside of the car so that the outer dimensions remain

If problems occur with the extrusion con trol the direction of the surface normals As we already know when polygons are created manually it is possible for the normals to be turned around This should be checked on all models and then fixed automatically with the ALIGN NORMALS function

In order to model the tailgate we need only a spline to provide us with the profile

This spline is widened in the direction of the symmetry plane with an EXTRUDE NURBS Set the interpolation of the IMMEDIATE POINTS to UNIFORM because the subdivision of the EXTRUDE NURBS depends directly on the number of INTERMEDIATE POINTS in the spline A value of three SUBDIVISIONS should be enough Then the EXTRUDE NURBS can be converted (see Figure )

Select the right edge of the converted EX TRUDE NURBS and in the COORDINATE MANAGER set the expansion of these points in the X di rection to This will assemble the points into a vertical line as shown in Figure

In the COORDINATE MANAGER the value for the X position can also be set to and con firmed with APPLY as long as the points are still selected It places the edge of the object ex actly onto the symmetry plane

Activate the SCALE tool and move its MOD ELING AXIS to the lower end of the POINT SELEC TION (see Figure )

Adjust the upper edge of the tailgate to the shape of the rear roll bar by scaling the points at the right edge of the object

Add another vertical subdivision which will be adjusted the same way The result is shown in the upper image of Figure

Then we add the obligatory subdivision along the edge and thicken the whole object The faces on the symmetry plane then get de leted (see Figure )

Now we will model the small rear spoiler of the tailgate (see Figure )

Select a few polygons above the ridge of the tailgate and extrude them upward Be sure to select faces only on top of the tail gate Rotate the polygons by entering a value of for the Y rotation on the plane in the COORDINATE MANAGER

In the view from above move the points so that an arc is created from the outside in ward This shape is also shown in Figure

Do not forget to remove the faces in the symmetry plane that were created by extrud ing the rear spoiler

The bottom image of Figure shows the opening that is visible again after the deletion of the faces

Add a continuous subdivision to the rear wing This can be done like in Figure with the EDGE CUT tool

Use the new points to shape the wing fur ther A possible result is shown in the two lower images in Figure

In the middle of the rear wing there is a brake light as shown in the photo of the rear in Figure The light could be shown with a simple projection of the right material but I would like to add this brake light as its own ob ject This saves us the use of UV coordinates and highresolution textures in order to create the required edge sharpness of the object

Start by selecting polygons of the rear edge of the spoiler and extrude them inward as a group This will sharpen this area of the spoiler

in the HYPERNURBS object as can be seen in Figure

Then select a Cshaped area in the middle of the spoiler as also shown in Figure

Extrude these faces inward to get addi tional points within the faces

Move these new points so that the edges border the shape of the brake light (see Figure )

Afterward select the faces in the area of the light and separate them with the SPLIT com mand into a new object

Depending on how exactly this object should be modeled the faces of the separated

brake light can be thickened by extrusion and the original faces of the tailgate can be shaped into a depression by extruding and moving them However it would be enough to delete the original faces of the spoiler and to close the resulting hole with the separated brake light The results are shown in Figure

A plastic part covers the engine in the center of the tail This part can be seen well in Figure

Two splines are enough for defining the shape One spline describes the outer profile and the other one the shape of the opening where the license plate is located

We can start with a PLANE object with a height of nine segments and one width seg ment Convert this plane and let the points snap to the outer spline as shown in Figure

We need additional subdivisions to model the shape of the recess and the downward turning corners of the lower area of the cover

Select all horizontal edges of the object and split them one time with the EDGE CUT tool Additional vertical cuts at the height of the

corners and where the recessed area starts can be added with the KNIFE tool

Use the added points to contain the outer shape and the edge of the recess in the middle (see Figure )

These steps have to be done only on one side of the object The other half will be sup plemented later by the symmetry object

Select the faces that are within the inner spline and extrude them a bit; in a second step extrude the faces inward to the desired depth of the recess Scale the extruded faces along the Z axis to a value of so that a vertical face is created

The surrounding edge of the cover will also be extruded inward with the EXTRUDE tool (see Figure )

Now we can concentrate on the accurate fit of the already modeled tail (see Figure )

Therefore delete all points to the right of the center of the plastic cover and subordinate it under a smoothed SYMMETRY object

Check if the cover fits well into the tail at the sides

A recess with air vents is still missing above the cover These will be extruded di rectly out of it Therefore select the upper faces including the rounded upper corner The second image from the top shows this se lection in Figure

Extrude these faces in one step upward and select the faces at the front where the opening is to be created This step can be seen in the third image of Figure

Extrude these faces slightly inward and use these small faces to frame the edge of the de sired opening This is shown in the last image of Figure

This precisely shaped polygon group will be moved into the cover with the EXTRUDE command and then deleted What is left is a narrow gap in the cover which is shown in Figure

The gap is stabilized by five slim supports We need two complete supports and half of one as all objects are mirrored by a SYMMETRY object

These elements could be modeled directly out of the engine cover but then we would have to make many additional cuts It is easier to just use small cubes that are subordinated to the cover as separate objects This works well without having to connect the two ob jects as shown in Figure

Just remember to convert the third set of cubes and delete the right half of their points as they will be mirrored and merged in the middle

Now the rear apron has to be pulled down along the upper edge of the motor cover so that the objects are snug

The arrows in Figure indicate the movement of the points of the tail object For a better understanding take another look at Figure

This completes this part and we can con tinue with modeling of the lower bracket

The lower part of the tail is closed in by two grids and one bracket These parts are shown in detail in Figure We will start with mod

eling the bracket and later we will put the grids into the openings

As a basis for the model we will use a slim cube with four subdivisions in the X direction and three subdivisions in the Y and Z direc tions (see Figure )

Place the cube parallel to and under the en gine cover Then convert the cube and move

the segments in such a way that the vertical braces can be extruded from the middle por tion Figure shows the desired shape in the lower image

Align the points in the center so that they are placed exactly on the symmetry plane Then the right part of the cube can be deleted

This part will be added again by the SYMMETRY object

Now extend the vertical part of the bracket in the center until it reaches into the lower part of the engine cover plate The polygons on top of the bracket can then be deleted

Subordinate the half bracket under a SYM METRY object and HYPERNURBS object to see how it looks

The model can be subordinated under an already existing SYMMETRY object so as not to create a new symmetry for each object (see Figure )

The visible crease around the vertical bracket can be achieved by making horizontal

cuts at the base and in the middle of it The ar eas for the cuts are shown with arrows in Fig ure

We will use a stylized grid to close the space between the bracket and the engine cover This grid will also be used in other areas of the car

First the area has to be closed with an ob ject This can be done with the cap of an EX TRUDE NURBS object

In order to generate the necessary spline that fits into the opening we will convert an EDGE SELECTION into a spline by using the com mand STRUCTUREEDIT SPLINEEDGE TO SPLINE Figure demonstrates this with an EDGE SE LECTION at the edge of the bracket

This spline then has to be set to along the Z axis so that all spline points are on one plane This step is repeated with the EDGE SELECTION along the bottom of the engine cover This edge will also be converted into a spline Con nect both splines with FUNCTIONSCONNECT The result is combined into a single spline with

JOIN SEGMENTS and will then be closed with the CLOSE SPLINE option

Subordinate the spline under an EXTRUDE NURBS object and activate FILLET TYPE EN GRAVED to create the front cap The result can be seen in Figure

The imprinted grid structure will be com pleted with duplicated cubes Therefore cre ate a cube with an edge length of units in the X and Z directions The height can be kept at units for the moment

Rotate the cube so that it lies partly sub merged in the plane created by the EXTRUDE NURBS and only shows one edge (see Figure )

Move the cube into the upper left corner of the EXTRUDE NURBS plane where the first crossbar of the grid is supposed to be

Create a linear twopoint spline starting from the current position of the cube to the lower right corner of the EXTRUDE NURBS plane The course of this spline is also shown in the middle image of Figure

Select the grid cube and select FUNC TIONSDUPLICATE Choose the ALONG SPLINE mode in the dialog and pull the path spline into the SPLINE field of the dialog Now create real copies of the cube by pressing the APPLY button (see Figure )

Unfortunately duplication along the spline does not offer an interactive mode where the course of the spline could be changed after ward When duplication of the cubes is not the

way it should be use the UNDO command change the course of the spline and use the DUPLICATE function again

The only thing left is the individual adjust ment of the length of each cube copy so that the EXTRUDE NURBS is always covered

Work in the opposite direction and repeat this procedure with a second cube Duplicate it along the spline from the upper right to the lower left A possible result is shown in Figure This component is now complete

The tail lights are framed by the tailgate the side rear windows and on the bottom by the rear apron (see Figure )

The basic shape of the tail light can be put together by separating polygons from these already modeled parts Therefore use the SPLIT command to separate the necessary polygons from the named components and connect these faces with the CONNECT command into one object

Delete unnecessary points in this object and connect the remaining faces to a closed polygon ring as shown in Figure

Use the CREATE POLYGON function to close the front of the tail light as evenly as possible with polygons

Select these new faces and extrude them a bit inward so that the outer edge is sharp when smoothed by the HYPERNURBS object (see Figure ) Then make new faces at the rear of the lights using the same principle These new faces do not have to be extruded in ward

Create three basic cylinder objects with a radius of units each and arrange them as shown in Figure

Use multiple BOOLE objects to merge the first two cylinders to each other and then to merge this BOOLE object with the remaining cylinder into one unit

This group will then be combined with the tail lights in INTERSECT mode The result can be seen in Figure

Because the shape has many hard edges we need to duplicate the boole group and con vert it into a POLYGON object

Select a continuous edge loop at the con verted object and convert it to a spline Now the spline type can be changed to BEZIER and the shape of the spline can be adjusted with the

tangents Then subordinate the spline under an EXTRUDE NURBS object with rounded caps These steps can be seen again in Figure

The spline diameter is automatically ex tended by the rounding of the caps The origi nal cylinders can therefore be subtracted from this shape with a BOOLE object

As a first step we will need three cylinder objects as shown in Figure There the blue cylinder will be subtracted from the green one

The result of this action together with the red cylinder is again subtracted from the EX

TRUDE NURBS object The resulting shape is also shown in Figure

Now only the third light is missing First its yellow cylinder shown in Figure will be combined with a cube in a way so that it does not penetrate the rear of the light The white cylinder is also subtracted from the yellow one creating the same crescentshaped recess that we produced with the green cylinder

This BOOLE object will then also be subordi nated under the red cylinder Therefore this

shape will also be subtracted from the shape of the tail light and leaves the desired recess

Adjust the first model of the tail light so that the three lights have enough space to fit inside (see Figure )

Make a POLYGON SELECTION of the rear faces of the tail light These faces will later get a re flective material whereas the front will be covered with a transparent material

Then convert the BOOLE hierarchy of the tail lights and select the faces that represent the actual lights These faces are marked in red in Figure

Extrude these faces in the world Z direction toward the glass and use the CREATE CAPS op tion of the EXTRUDE tool

By extruding the faces of the brake light inward its ringshaped structure can be rec reated

Take a look at the real photo in Figure Create polygon selections for the surfaces of the lights that will get the same material

Later we will have to deal with three colors of light lenses in white red and yellow

I already applied a transparent material to the light lens as shown in Figure so that the position of the lights can be seen more easily I will talk about the material used at the end of this example

Maybe you already noticed in the photo that this type of car has large gap sizes which means that the components are separated from each other by a large gap

We will simulate this by a small movement of the points in the edge areas of the compo

nents The desired effect is marked with ar rows in Figure

Figure also shows that simple cube ob jects with an extrusion at the upper end were integrated into the indentation of the engine cover They simulate the license plate lights

We will continue with the air vents on the side of the car These also have to be closed with the stylized grids

The technique we will use here is identical to the one used at the tail bracket Therefore it is not necessary to go into detail here

The result is shown in Figure There the following steps can be seen as well These are modeling of the air vents in front of the wind shield and the mount for the windshield wipers

In front of the windshield there is a complex shaped plastic part that aside from other things contains the air vents for the fan on the inside of the car

We will construct this shape primarily with the help of splines Start with placing two paral lel spines in the area in front of the windshield

Extract an EDGE SELECTION as a spline from the edge of the trunk lid and duplicate the spline We do this so that the shape of the spline fits exactly to the trunk lid

Combine both splines with a LOFT NURBS object as shown in Figure

In order to achieve the curvature of the plas tic part create another copy of the spline and move it so that the LOFT NURBS takes on a shape that is slightly upward This shape can be seen quite well in the side view of Figure

The shape can now be mirrored and com pleted with a SYMMETRY object Now some of the faces of the object have to be moved up and down

The shape of the part that has to be moved upward can be recognized as a dark spline curve in Figure This curvature is shown in the photos of Figure There at the driver and passenger sides the part of the compo nent can be seen that is moved upward The el liptical air vents are also in that area

Place the spline parallel to the ground above the surface that was generated by the LOFT NURBS The arrow in Figure shows the position of the spline in the side view

Subordinate the spline under an EXTRUDE NURBS object that extrudes the shape verti cally downward and creates caps This shape is marked in red in Figure

Then create a copy of the SYMMETRY ob ject which has the LOFT NURBS object subor dinated and convert this copy to a POLYGON object

Finally use a BOOLE object in INTERSECTION mode to combine the EXTRUDE NURBS and the new POLYGON object The result is shown in the middle of Figure

Activate the HIDE NEW EDGES option in the BOOLE object before this object is converted to a POLYGON object This changes the face auto matically into an NGON

Extrude the NGON upward until it is at the same height as the trunk lid The upper edge can then be rounded a bit with the BEVEL func tion The result is shown in Figure

Now we will cut out the slits in the air vent This is done by subtracting a series of distorted cylinders from the previously extruded object with a Boole operation

In a moment we will discuss the additional steps that are necessary to end the holes at a certain distance from the edge of the object First objects have to be created that have a suitable shape for the air slits

Therefore we use slim cylinders that will be distorted along the axis Open a basic cylin der object with a radius of units and a height of units A circumference of segments should be enough so that the boole operation will not create too many faces

In object mode (see the icon in Figure ) we can now distort the cylinder by scal ing it in the local Z direction The advantage of this method of scaling is that the cylinder does not have to be converted and therefore keeps all parametric properties

When the size and the height of the cylin der are set we will make two copies and place them on a slight angle to simulate the air vent slits Figure shows the placement in dif ferent perspectives

Now the moment has come to convert these cylinders because they will have to be duplicated along a path Then combine all three cylinders to a new object by using the CONNECT command in the FUNCTIONS menu

Use the command STRUCTUREAXIS CEN TER CENTER AXIS TO to place the local axis sys tem in the center of this object

In the AXIS CENTER menu there is another mode for putting the axis system into a new place For example the axis system can be moved to the position of the parent object or detailed settings for the alignment of the local axis system can be made in the AXIS CENTER… entry This function is especially helpful when working frequently with imported D data

The axis systems of D data are often far outside the actual geometry which makes it difficult to edit the objects such as rotating or scaling them evenly

We will use a spline again to allow the cop ies of the cylinder to follow the plastic part in a slight bow This step should be familiar from the creation of the grid structure at the tail and the sides of the car

My settings for the DUPLICATE tool can be seen in Figure The number of copies de pends on the size of your cylinder and the length of the used spline and can therefore differ

Note the activated SCALE function of the duplicates This way the copy can be scaled down toward the end of the spline path Ide ally the cylinder copies will be parallel to the lifted shape until the end of the plastic cover

Actually we could subtract the copies from the plastic part with a BOOLE object but then we would get holes in the right part that would extend into the wall of the plastic cover

Therefore our goal must be to first confine the cylinder group so it is located entirely within the cover

Create a copy of the spline of the lifted parts and pull this spline higher than the up

permost edge of the plastic cover All points of the spline that represent the left part of the cover can be deleted Of interest to us is the area around the air vent slits only

Subordinate the spline under an EXTRUDE NURBS object and extrude the spline vertically downward

The lower end of the EXTRUDE NURBS should be located under the cover The result ing object is shown in a view from above in Figure

Scale the spline of this shape a bit at all sides The shape of the EXTRUDE NURBS object should not cover or breach the plastic cover at the outside

Create a BOOLE object in INTERSECT mode and subordinate it together with the dupli cated cylinders under the EXTRUDE NURBS ob ject For clarity reasons the cylinders should all be combined to one object with the CON NECT command

Only the cylinders that are placed within the EXTRUDE NURBS and are located within the cover should be left over These cylinders can then be subtracted with another BOOLE object from the lifted cover to create the air slits (see Figure )

Convert this group of BOOLE objects to get a POLYGON object of the lifted cover including the air slits

In EDGE mode the edges of the air slits can now be selected with a LOOP SELECTION as shown in Figure Activate the SELECT BOUNDARY LOOP option in the LOOP SELECTION dialog to avoid errors in the selection This way only the open edges of the holes can be selected

When all hole edges are selected they can be extruded downward to simulate a material thickness This effect can also be seen in Figure

To the left and right of the lifted cover are dents in the surface We will draw splines fol lowing their contours as shown in Figure

With an EXTRUDE NURBS object these splines can be moved downward until the cover is pierced Then close all caps

Use a new BOOLE object in SUBTRACT mode to subtract this EXTRUDE NURBS from the converted original shelf As you remember we created a copy of the upward bent shelf at the beginning Two openings in the shelf are left over

Extrude the open edges of these holes downward and close the holes with the CLOSE POLYGON HOLES function The result can be seen on the bottom of Figure

Select multiple polygon rows at the upper edge of the former shelf This selection is shown in Figure

These faces are supposed to be a kind of seal for the windshield Thus extrude these faces together a bit upward and then activate the ROTATE tool

In the ROTATE tool’s settings for the MODEL ING AXIS choose NORMAL for the ORIENTATION and select the ALONG NORMALS option This setting forces the faces to rotate only where nonselected faces are bordering

Because of this the faces at the edge of the windshield arch upward and at the front edges downward This is the shape of a typi cal seal

It is almost done as the actual windshield can be created easily by overlaying it with sim ple splines and a polygon skin

Therefore we can create simple twopoint splines as in Figure When D snapping is activated they can be snapped to polygons at the front roll bar and on the bottom to the re cently modeled seal

Switch the interpolation to BSPLINE and add a point to the spline with ADD POINT at about the middle of every curve This addi tional point is used to bend the profile of the window outward

Then subordinate the splines in the right order under a LOFT NURBS object The splines have to be created only for onehalf of the windshield The missing half can be added with a SYMMETRY object as long as the middle spline is placed exactly on the symmetry

For a seal along the upper part of the wind shield we can either use a polygon strip sepa rated from the roll bar with the SPLIT command and extruded with the CREATE CAPS option or change the encircling edges of the converted windshield to a spline and subordinate it along with a circular profile under a SWEEP NURBS object The result could in any case look like the bottom image in Figure

The windshield wiper contains separate seg ments that are connected to each other with moveable joints This allows the wiper to fol low the curvature of the windshield and to cover the largest possible area

We will start with a simple cube that is ad justed to the angle of the plastic cover and

placed to the right of the air slits Model two creases into the cube so that it runs parallel to the base and then moves away a bit from the window at the upper end (see Figure ) Then select all faces at the bottom and front and delete them

The remaining faces will be thickened with the EXTRUDE command and its CREATE CAPS op tion The result is shown on the bottom of Fig ure

Put a simple cube at the base of the wiper arm The HYPERNURBS smoothing will turn it into a sphere that penetrates the wiper arm on top thus serving as a pivot (see Figure )

Another slim cube should now extend the arm and represent the second segment of the wiper In order to have the same direction as

the first wiper cube we can use the TRANSFER function in the FUNCTIONS menu

Therefore select the new cube and use the TRANSFER function Pull the modified cube of the first wiper segment from the OBJECT MAN AGER into the TRANSFER TO field

With the diverse options in the dialog of the TRANSFER tool it can be determined which properties will be transferred to the selected object We leave everything activated and ap ply it with the APPLY button The new cube will then jump to the position of the first wiper segment and also takes over its direction Now the new cube can be moved along one of its axes in the direction of the tip of the first cube

Use of the TRANSFER command is espe cially helpful when the objects in the OBJECT MANAGER are not sorted in a hierarchy In our case we could have subordinated the new cube under the first segment and set the local position and rotation values to in the COOR DINATE MANAGER The result can be seen in Figure

Adjust the shape of the new cube to the first wiper segment so that a joint is created A suggestion on how to model it can be seen in the series of images in Figure

With multiple extrusions the end of the second segment can be shaped into the small holding strip where the actual wiper will be attached

Position a new cube across the end of the second wiper segment as shown in Figure and shape the rocker of the attached wiper out of this cube

An even subdivision of the edges of this rocker allows the deletion of single faces on the top in order to achieve the characteristic look of the holes (see Figure )

Select the faces on the bottom of the wiper extrude them a small amount inward and then delete them These faces are marked in red in Figure That way the rocker is opened up on the bottom and at the same time gets a massive outer edge that will help with the HYPERNURBS smoothing

Again we need a new cube that will repre sent the connection points for the wiper blade

Place slim cubes at the end of the rocker and give them a slightly bent shape as seen in Figure

Be sure that no part of the wiper will pierce the windshield Adjust the tilt of the second wiper segment if necessary When this ele ment and the two cubes for the wiper blade connection are subordinated under the rocker

then the whole wiper can be removed from the windshield

Finally create a simple spline and with ac tivated D snapping snap its points to the edges and polygons of the wiper frame

In connection with a triangular profile which can be created with an NSIDE spline generate the rubber lip of the wiper blade

with a SWEEP NURBS This object is indicated by an arrow and a slightly darker coloring in Figure

Figure also shows the duplicated sec ond wiper which was moved to the center of the plastic cover There the length and tilt of the wiper might have to be adjusted so that this wiper lies snugly on the windshield

We already created a small recess at the up per right corner of the door There the door handle and the whole side guide for the win dow will be placed Then we will model the exterior mirror

The shape of the door handle can be de fined by two splines for the outer contour and the transition to the recess under the handle

After these splines are drawn we will create a basic disc object and place it on the plane of the template splines

The disc should have at least two segments so that its points can be snapped to the two splines after the conversion Figure shows the already converted and adjusted shape of the disc As a comparison Figure shows the real images of the door handle and the ex terior mirror

Because the triangle in the center of the disc will not look good when smoothed with a HYPERNURBS we will delete these faces and add two loop cuts to the remaining faces as shown in the uppermost image in Figure

Pull these edge loops a bit outward to show the bulge of the object

The inside will be closed with the CLOSE POLYGON HOLE function We scale the resulting face in the center of the disc with the EXTRUDE INNER function in two steps and move these faces in the direction of the car interior

In order to gain more control over the kind of closing faces in the center of the recess we will use the FUNCTIONSREMOVE NGONS com mand and adjust these faces if necessary If possible only rectangular polygons of equal size should be used The result is shown in the third image of Figure

A new cube object will be placed across the front of the recess and reshaped into a handle Now this area already has enough details

Next in edge mode select the outer edge loop of the door handle recess and extrude it a bit toward the car interior

The door handle recess will therefore ac quire a thickness and we can select and ex trude the faces at the upper edge in order to model the triangular area above the handle

Figure shows the used selection of the edge faces and the tapered shape of the trian gle after extruding them in the upper part

In the same manner select the faces at the side of the door handle recess and extrude them toward the front of the car parallel to the upper edge of the door This creates the seal between door and side window as is shown in Figure

The exterior mirror will be modeled from a cube (see Figure )

After we have placed the cube at the cor rect spot next to the door we convert it add

new cuts and move points to create the char acteristic shape

The actual mirror surface is created with in ner and normal extrusions Afterward sepa rate the faces from the object and save the se lection as a POLYGON SELECTION tag for the ap plication of materials later on

At the side of the object extends an area to ward the door This represents the hinge of the mirror and can be seen in the upper image in Figure

The distinctive arrow shape of the back of the exterior mirror can be created by constrict ing some points and then extruding them to ward the outside The corresponding faces are marked in red in the middle of Figure

The exterior mirror itself is connected to the door with a simple triangular face

Adjust a simple flat cube to the tilt of the front roll bar above the door and create a raised area starting from the center There the external mirror can be attached as in Figure A more elaborate creation would only be necessary for closeups

We will create a POLYGON SELECTION along the front roll bar above the mirror triangle Then this selection is separated into a new object

and extruded which results in a simple seal as shown in Figure

Afterward we will define one part of the roof with some splines in a LOFT NURBS ob ject Then we will convert the LOFT NURBS ob ject and thicken the shape by extrusion with CREATE CAPS option

This car has two separate roof halves that can be removed to change the car into a con vertible Between these roof halves is a seal

For its modeling we could use the first spline of a roof half subordinated together with a pro file spline under a SWEEP NURBS object An other possibility would be to separate a poly gon strip from a roof half and to extrude it

Create another seal the same way with the edge of the roof above the side window

Finally use a small cube as the window and adjust it after the conversion to the available space The result can be seen in Figure

The tailgate is held by two complex hinges (see Figure ) We will not model their shape up to the smallest detail but will rather show only the most important features

The best way is to start with a cube and ad just it with cuts and extrusions to the desired shape

Place the scaled cube as shown in Figure at the edge of the rear roll bar and shape the converted cube to a wedge or teardrop shaped object This shape would already be enough to show the hinge

When more details are needed then the component groups of the hinges can be sepa rated from each other by means of extruding small polygon strips (see Figure )

The buttonshaped connection element can be placed as a separate cube in a recess at the head of the hinge (see Figure )

Depending on each person’s own aspirations we could spend a long time modeling various small parts apart from the complete interior However because I would like to discuss other projects I will talk only about additional parts of the car worthy of being modeled

The grid in the mouth of the front end is still missing and can be modeled using the same method as the tail grid

The only difference here is that this grid needs to be bent in order to adjust to the shape of the bumper The BEND deformer should be subordinated under the group of cubes shown in Figure

A tapered cube will replace the side turn sig nal on the fender in the HYPERNURBS object

The antenna can be modeled out of a slim cylinder Its points at the bottom would have to be adjusted to the shape of the body Then add a loop cut above the adjusted points and extrude the newly created faces at the lower-Figure : Details of the hinge

end of the cylinder outwards This step is shown in the first two images of Figure

Afterward the faces at the upper end of the cylinder are extruded to shape the actual an tenna The finished shape is also shown in Fig ure

The gas cap is made out of a TUBE object which has holes cut into it with a boole opera tion I used spheres in an ARRAY object so that the holes automatically get a beveled edge

Cylinders with six subdivisions at the cir cumference become the hexagonal screw heads which can be placed in the recesses of the TUBE object with another ARRAY object

A DISC object which is placed in the middle of the TUBE object represents the actual gas cap A clip at the edge can be separated by add ing points at the edges manually

These additional points which form a semi circle and the clip created by lifting the edge points at the disc can be seen in Figure

Next the wheel housing will need to be closed Separate a continuous polygon strip from the fender and extrude inward an EDGE LOOP of these separated polygons

A manually created polygon borders the arched opening at the end of the wheel hous ing This opening can then be closed with the CLOSE POLYGON HOLE function

These steps are shown in Figure It also shows that the same procedure is used for the rear wheel housing

The tires of the car can quickly become a poly gon trap what with all the complex rim and

profile structures and could easily use more polygons than the whole car

Therefore we need to find a compromise This automatically excludes the use of dis placement maps for simulating a tire profile because the whole tire would be subordinated unnecessarily high

I start by searching the Internet for a useful image of a profile These kinds of images can be found for example directly at a few tire manufacturer’s websites (see Figure )

In a graphics program I convert the image to a black and white one with high contrast and load it into a VECTORIZER object which is found at the spline objects

The TOLERANCE value of the VECTORIZER ob ject determines the maximum deviation of the created spline from the contours of the loaded image template We will use a value of for the most accurate result

The WIDTH value determines the scale of the calculated spline The VECTORIZER object could also be converted and the resulting spline could then be scaled manually

Basically the VECTORIZER spline could be subordinated directly under a NURBS object like a regular spline However I want to use the calculated spline only as a base for the sim plified modeling of the profile

The loaded profile image already portrays a segment of the tire profile that can be tiled Therefore we can place multiple copies of the VECTORIZER object on top of each other to get a better idea of the structure of the profile One copy of the VECTORIZER object is enough as shown in Figure

Create an empty POLYGON object from the OBJECTS menu and fill it with simple polygons to cover the most important shapes of the tire profile

Copy the created POLYGON object and move the copy so that the desired distance between the profile segments is shown

Then combine both profile segments to a new object and create the missing polygons to close the gaps between the segments The re sult is shown on the bottom of Figure

After this delete the duplicate faces of the object This leaves us with a segment of the tire profile that can be put next to each other multi ple times (see upper image of Figure )

Use the BEVEL and EXTRUDE command to cre ate the raised profile areas out of the segment Then find out how high the segment exactly is This can be done by selecting the highest and lowest points and then finding the distance be tween these points in the COORDINATE MANAGER

The resulting value can be entered into the DUPLICATE dialog to determine the movement along the height The number of copies can be set to for now while real copies and not in stances have to be created

The result is a long profile strip that looks like a tire track Check if the edges of the pro file segments are placed exactly next to each other If not then the MOVE vector has to be checked in the DUPLICATE dialog

We will use the CONNECT object in the OB JECTSMODELING menu so that the separate profile segments can later be merged into one continuous object

This object works like the OPTIMIZE com mand The TOLERANCE value determines the area around each point where elements merge when the WELD option is activated

This is an advantage especially when the ob jects grouped under the CONNECT object are go ing to be smoothed as well by a HYPERNURBS object The result is a connected surface

Subordinate the NULL object group with the copies of the profile segments under the CON NECT object as shown in Figure Also pull the original profile segment under the NULL ob ject so that it can be connected and optimized

Set the PHONG mode of the CONNECT object to MANUAL This way we can assign a PHONG tag to the CONNECT object later and influence the surface shading ourselves

Now the profile strip needs only to be bent into a ring This is not a problem for the al ready familiar BEND object

Open a new BEND deformer and subordi nate it under the null object along with the copies of the profile segments Adjust the posi tion and height of the BEND object so that the upper and lower borders of the BEND cube are placed as exactly as possible on the points of the profile strip The points should meet after being bent These places are marked with ar rows in Figure

When the BEND object is set to a strength of ˚ in the right direction then the upper and lower edges of the profile strip should fit exactly on top of each other and become merged by the CONNECT object

When this does not work at the first try zoom in to the area where the ends meet Change the height of the BEND object in small steps until the edges are close enough to each other to be merged by the CONNECT object

Now the most difficult part of the job is done and we can concentrate on the outward bend and the walls of the tire

Deactivate the BEND object with a click on the checkmark in the OBJECT MANAGER and cre ate two new BEND objects which will be placed in the group of profile copies

It is important that the two BEND objects ap pear first in the order of the group because these bends have to be calculated before others

As shown in Figure deformers are used to bend the sides of the tire In order to

not pull the profile too far around the corner we can select the sides of the profile parts that stick out and scale them down a bit

Use the MODELING AXIS and move them to the position of the profile faces that are not raised That way it can be comfortably scaled along the Z direction as shown in Figure

After this activate the third deformer again to see the complete tire

Select the CONNECT object and convert it when you like the resulting shape We now have one polygon object that contains the op timized structure of the whole tire

With a loop selection of the edges at the side openings of the tire make two edge extru sions to further round the hull of the tire along the walls and to bend the tire in the direction of the rim that still needs to be modeled This is shown on the bottom of Figure

For the rim we need a basic OIL TANK object as the hub and two slim cubes which will be placed as shown in Figure

When you like the shape of the cubes then combine them into one object and create two additional copies

These copies will be rotated ˚ and placed so that a threepointed starshaped rim is cre ated (see Figure )

Group the two connected cubes under the OIL TANK so that the placement of the cube spokes is exact Then create two copies of the OIL TANK group and turn these in the COORDI NATE MANAGER always by ˚

Now these three rotated CUBE objects can be combined into a new POLYGON object and the two additional OIL TANK objects can be de leted again

Delete all faces in the converted OIL TANK object that are not located directly under the end of the cubes What’s left is a slightly funnel

shaped ring surface as shown on the bottom in Figure

Add edges with the KNIFE tool in SINGLE LINE mode at the remaining OIL TANK faces where the cube spokes should connect later on Place the cuts as exactly as possible along the contours of the CUBE objects

The goal is that polygons with the exact same shape are placed where the cube meets the OIL TANK faces When the faces at the OIL TANK are deleted it will then look as shown in Figure

For easier orientation the faces of the former OIL TANK object were colored in blue The openings created by deleting the faces are clearly visible The cube spokes fit exactly into these holes

Now all objects of the rim can be combined into one new object and with the STITCH AND SEW function the points of the spokes can be

snapped to their corresponding locations on the OIL TANK faces The result can be seen on the bottom of Figure

The outer edge of the rim will be edited similarly We will use a basic DISC object con vert it and add fitting cuts parallel to the spoke ends (see Figure )

In order to place the points which were cre ated by the cuts exactly on the radius of the DISC later on select the two edge loops at the outer and inner openings of the disc Create two curves with STRUCTUREEDIT SPLINEEDGE TO SPLINE before adding the cuts

Switch the interpolation of these splines to CUBIC Then the points can be snapped onto the circular splines with D snapping

Add an additional subdivision in the outer area of the DISC and pull it slightly to the front of the rim This creates the typical beading at the transition between rim and tire as shown in the first two images of Figure

Then connect the ends of the spokes with the corresponding openings at the outer ring of the rim For this reason the spoke cubes need to be open at the end This procedure is the same as the connection of the spoke cubes with the hub of the rim

Now it is time to match the size and posi tion of rim and tire so that we have a unit This is shown in the third image of Figure

In order to avoid being able to see the in side of the tire when looking through the spokes we have to give the rim some depth Therefore select the open edges between the spokes of the rim and extrude them in the di rection of the symmetry axis of the car The re sult is shown on the bottom of Figure

Gaps behind the spokes have to be closed manually as shown on top of Figure This will create a continuous drum

In order to attach the rim to the axle we will need to add bolts and the necessary holes for them

Create an ARRAY object and subordinate a circle under it Align the ARRAY object in a way that the circles are parallel to the hub of the rim We need three mounting bolts and there

fore have to create only three circles with the ARRAY object

Duplicate the ARRAY object and convert the copy Normal splines will be created which we will now project onto the surface of the hub

Activate the editor viewport where the hub and circles can be seen from the front and se

lect all three circle splines that were created by converting the ARRAY object

Select the EDIT SPLINESPROJECT in the STRUCTURE menu and set the MODE to VIEW in its dialog in the ATTRIBUTE MANAGER This will project the selected splines along the line of sight onto the next object behind the spline The result can be seen in the second image of Figure

Now the selected faces shown in Figure can be extruded together toward the in side and the newly created points can be snapped to the three splines

All polygons that lie within the circles will then be extruded toward the inside of the rim to create the holes

Subordinate basic cylinder objects under the still existing ARRAY object and set their number of circumference segments to This is enough to show the bolt heads

The ARRAY object has to be moved far enough into the rim so that the cylindrical bolts can be placed in the holes of the rim

Close the center of the hub with the CLOSE POLYGON HOLE function and extrude the open edges of the hub and spokes just a bit This will give more volume to these parts as shown in Figure There the bolts can be seen in side the holes in the center

Now all the parts of the wheel have to be grouped together in a NULL object and copies placed inside the wheel housings

At the rear axle of the car the wheels can be mirrored to the other side with a SYMME TRY object This does not work with the front axle as the wheels will eventually be rotated as if the driver were turning the steering wheel Thus we need two independent copies of the wheel

This concludes the modeling of the car We could certainly build more details and finish the interior of the car

You should by now know the process enough to finish these parts yourself and you have probably realized how quickly complex geometry can be created from simple basic shapes For example the steering wheel could

be easily made out of a basic TORUS object or the seats out of a cube and placed in a HYPER NURBS object

In my opinion though the car is ready to be displayed as a look at Figure proves I added a FLOOR object from the OBJECTSSCENE menu to simulate the floor

An AREA light with AREA shadows and a dome shape light the scene The car would look even better with the appropriate finishes Let us take a short look at this subject

We will need only a handful of materials for the car The main goal is to simulate the high gloss finish

The properties of this paint are the display of clear and highcontrast colors and strong re flections The reflective aspect of the paint can especially be used as the base for the material itself Objects that will be reflected in the paint have to be added to the scene as well

I have chosen a bicolor paint job with dif ferent beige tones As is common with these flipflop paints the color changes depending on the curvature of the surface This effect can be simulated easily with the FRESNEL shader

Create a new material and load the FRESNEL shader into the COLOR channel The right edge of the FRESNEL gradient represents the color that will be visible when the viewing angle is extremely flat

The color value of the left edge of the gra dient will be applied to all surfaces that are perpendicular to the line of sight

I used a gradient from dark orange to a warm yellow tone as shown in Figure I also used the FRESNEL shader in the REFLECTION channel so that the intensity will be reduced depending on the severity of the curvature of the surface

This is not really correct physically but it will create a soft fading of the reflections on the body

By multiplying the brightness in the RE FLECTION channel the intensity of the reflec tions can be controlled without having to change the settings in the FRESNEL shader

Apply this material to all objects that have to be painted

Another difficult material to create is the one used for the rims or other reflective metal surfaces such as chromed parts

We will try a combination of distorted highlights and reflective properties

Create a new material and reduce the brightness in the COLOR channel to Many metals generally have a small surface bright ness Exceptions are colored metals such as gold or copper where the color value can be set higher We should mainly work with the reflective properties and the highlights

We therefore use the LUMAS shader in the LUMINANCE channel of the material to gain more control over the size and shape of the highlights

Deactivate the ACTIVE option in the SHADER PROPERTIES of the LUMAS shader because we do not want to create additional surface shading

We will use only SPECULAR and SPECULAR to create a diffuse light with an intense high light in the center The reason for using the LUMAS shader is the ability to calculate aniso tropic highlight distortions Therefore acti

vate the ANISOTROPY with SHRINK WRAP PROJEC TION

The direction of the projection of the anisotropy has to be checked with test render ings However we should wait until the light sources are set within the scene

We will need reflective properties as the third component of this material

Also I would like to use the FRESNEL shader but this time with a reversed gradient As a re sult surfaces that are bent farther away from the viewer have a stronger reflection than sur faces placed perpendicular to the line of sight

I will set the brightness of the gradient to so that it’s possible to see reflections on the front surfaces too All these settings can be seen in Figure

There are also many finishes on the car that are made of materials without reflective prop

erties These are for example the roof of the car the engine cover and the bumper in front

I will still apply reflective properties to these materials which might seem strange at the beginning

By dispersion of the reflections though these reflections will be blurred so much that they look more like light effects on the sur face This creates a more harmonious image overall especially when light objects are placed around the car in order to create reflec tions on the car

In a photo studio real light sources would do this job and therefore also light the matte parts of the car

The washedout reflections help simulate this effect The only disadvantage is the some times drastically increased render time for this material effect This effect should not be used when working on a slower computer

Figure shows an example of how the settings for the black plastic material should look

The NOISE shader in the BUMP channel will let the material look rough thereby creating a nice contrast to the painted surfaces

It does not happen often but it can cause problems in some situations I am referring to the restriction of materials to clearly sepa rated areas

We already learned about the ability to re strict materials to POLYGON selections What happens though when the polygon structure of an object has a direction that is different from the area to be textured?