Selections

While in Edit mode, the selection is restricted by the Selection Filter. With the Faces Filter activated, you can select faces, the Vertex Filter for vertices, and the Edge Filter for edges. ▶2.2

However, you’re not restricted to selecting just one kind of thing at a time. You can select vertices, edges, and faces together, without having to switch between selection modes. To do this, hold down the Shift key on the keyboard while clicking the filter mode icons from the 3D view toolbar. Clicking each button expands the Selection Filter, across vertices, edges, and faces. ▶2.3

You’ll often need to select many objects in a scene. Sometimes this will be to hide or show objects, or perhaps to delete objects, or even to move objects in one operation. Furthermore, you’ll need to select the same group of objects many times. This normally happens when you move, edit, or change objects and then later decide to change them back or tweak them further. One way to achieve multiobject selection

keyboard and click each object to select exactly the ones you need. ▶2.4 The problem, however, is that this can be time-consuming and tedious if there are many objects, and especially so if the objects are scattered all over the scene! You’d have to pick an object, move the viewport some more, pick another object, and so on-which is boring. A more promising solution, then, is to be found in Layers, which are accessed from the 3D view toolbar, provided the view is not in Local mode (see Chapter 1). ▶2.5 Layers let you collect multiple objects together, making it easier to view and select them and to reselect them. When objects are assigned to the same layer, they can be viewed together in isolation, separate from everything else. This lets you easily focus on only the objects you need. To assign the selected objects to a layer, start by choosing Object > Move to Layer from the 3D view menu (or press M on the keyboard). ▶2.6 Now you’ll see the Layer Picker menu. From here, click on a layer slot to move the selected objects to the destination layer. If the destination layer (the layer your objects are moving to) is different from the currently active layer (the layer you’re currently viewing), then the selected objects will disappear after moving to the destination layer. ▶2.7

in the viewport simply by clicking on the corresponding layer button, from the 3D view toolbar. Layers containing a dot icon have objects assigned to them, whereas undotted layers are empty and contain no objects. ▶2.8

When you pick a single layer, only the objects on that layer become visible in the viewport, and all other objects disappear. You can assign the same objects to multiple layers, and you can view multiple layers at the same time. To assign the selected objects to multiple layers, simply hold down the Shift key on the Layer Picker menu, which appears after choosing Object > Move to Layer from the 3D view menu. ▶2.9

You can view multiple layers at the same time by clicking Ctrl+ on each layer from the Layer Visibility buttons, on the 3D View toolbar. ▶2.10

While layers are a great way to group and organize objects, they’d be even better if Blender let us customize them further. It’d be great if we could name layers, select all objects on a layer, toggle layer visibility more intuitively, and even create layer groups that can be hidden and shown together in one operation. We can achieve these by using the Layer Management add-on. To install this, access the User Preferences window, and select the Add-ons tab. From here, type “layer management” into the search field at the top left-hand side of the window, and then Enable the Layer Management add-on option to enable the add-on. ▶2.11

When Layer Management add-on is enabled, a new tab, Layers, will have been added to the 3D view toolbar, at the left-hand side of the window. This tab is available only in Object mode. It is divided into two sections, Layer Management and Layer Groups. From the Layer Management tab, you can hide, show, rename, and organize layers. From the Layer Groups tab, you can hide and show multiple layers in one operation by grouping layers together. ▶2.12

From the Layer Management section (of the Layers tab), you can assign each layer a descriptive and meaningful name by typing a name into its text edit field. Using the Layer buttons, you can select or deselect all objects on a layer, lock or unlock all objects (preventing them from being selected), and even toggle their visibility as well as their viewport appearance (solid or wireframe display). ▶2.13

useful for quickly hiding or showing specific combinations of layers. To use this feature, first select a combination of layers from the Layer Management tab by clicking the eye icon for each layer you select. ▶2.14

Then, to save the selected combination, click the + button from the Layer Groups tab, to add a new group for the active combination. ▶2.15

After creating a layer group, you can hide or show all layers belonging to the group, lock them, change their display mode, and remove the group itself. ▶2.16

In addition to Layers, Blender offers Groups for quickly selecting multiple objects in a scene. Groups are unrelated to and separate from layers. Groups are ideal for selecting multiple objects in the viewport as though they were a single, combined mesh. To start using groups, select multiple objects in the scene that belong together or should be edited as one-just as though you were going to assign them to a layer. ▶2.17

To assign the selected objects to a group, choose Object > Group > Create New Group from the 3D view menu, or press the associated keyboard shortcut (Ctrl + G). ▶2.18

After creating a new group, the outline for the selected objects will automatically change to green in the viewport. A green outline indicates that the selected objects are part of a group. ▶2.19

Once you’ve made a group, you’ll probably want to name it meaningfully and also be able to select it (and all objects in the group) quickly. To do this, you can use the Outliner window. From the Outliner window, change the filter type to Groups using the Filter drop-down list. On selecting this option, the Outliner window displays only the groups in the scene,

belonging to the group, making it easier to view and select groups. ▶2.20

To select a group, just click its name in the Outliner window, and all objects belonging to the group are automatically selected too. When they are selected, you can Translate, Rotate, and Scale the group (as well as all objects within it) just like a regular mesh. You can also expand the group in the Outliner and select specific objects within the group individually. ▶2.21

To rename a group, double-click its name inside the Outliner, and then enter a new name. You can also hide or show all objects in the group by toggling the group’s visibility icon (eye icon) beside its name within the Outliner. ▶2.22

The selection methods considered hitherto focus on selecting one or more objects in the scene-specifically, complete and whole objects, like buildings, characters, weapons, and others. But when working in Edit mode, you’ll frequently need to select parts of a single object, such as the hood of a car mesh, the trunk of a tree, or the nose in a head. These parts are simply collections of vertices, edges, and faces; and they can be very time-consuming to select. In Edit mode therefore, you’ll want features for remembering combinations of vertices (just like Layers and Groups for objects) to help quickly select and reselect specific combinations at the touch of a button. One method for achieving this is vertex groups. A vertex group, simply stated, represents a saved selection of vertices within a mesh. To get started at using vertex groups, a new vertex group must be created. Select a mesh for which a group should be made, and switch to the Object Data tab from the Properties window. From here, you can view the Vertex Groups list, which lists all vertex groups associated with the mesh. By default, a mesh has no vertex groups. ▶2.23

To create a new vertex group, click the + button from the Vertex Groups list. After creation, the vertex group begins in empty state; that is, it contains no associated vertices. Before adding vertices, name the group appropriately-just by doubleclicking the vertex group name from the list and then entering a new name, such as ear, branch, handle, or whatever is suitable. ▶2.24

to the group, enter Edit mode for the object, and then select all the vertices to add. That is, select all the vertices whose selection you want Blender to remember. ▶2.25

While in Edit mode, and with the vertices selected, click the Assign button from the Vertex Groups list in the Properties panel to assign the selected vertices to the active

vertex group. Assigning the vertices does not change their structure or connectivity within the mesh in any way but only stores the selection. ▶2.26

After vertices are assigned to the group, you can easily select them by first choosing the appropriate vertex group from the list and then choosing the Select button

from the Properties panel in the Object Data tab. This selects all vertices in the mesh associated with the active group. Easy! Just a oneclick operation for selecting many vertices. ▶2.27

The selection techniques considered so far assume you already know what you need to select, whether objects or polygons. But sometimes you just need to make specific kinds of selections based on criteria, and you don’t know in advance which objects satisfy those criteria. A common example is selecting all NGons in a mesh-that is, all faces with more than four sides. NGons are generally bad for game engine models and models that must be animated or subdivided. For this reason, modelers and animators strive to remove NGons from models. Hence, it’s important to find, select, and address all NGons quickly and efficiently. In simple models, it’s easy to find and remove NGons. However, the issue becomes troublesome for complex models with many faces and polygons. In these models, NGons are not so clearly visible, and you’ll need Blender to help you find them. ▶2.28

Blender lets you select all faces in the model by the number of sides. To achieve this, select the model, and enter Edit mode. Then choose Select > Select All by Trait > Select Faces by Sides. ▶2.29

On choosing this option, some faces in the selected mesh may be automatically selected. You can control which faces are selected by using the settings presented in the Tools panel, from the Select Faces by Sides field. To find all NGons, change the Type field to Greater Than and the Number of Vertices field to 4, and then remove the check mark from the Extend field. The Extend check box,

unchanged and simply adds (extends) to it. ▶2.30

Once the NGons search settings are specified, all NGons in the mesh are selected. You can easily check how many faces and vertices were selected by reading from the info panel. ▶2.31

On complex meshes, with many curves, holes, and recesses, it can sometimes be difficult to spot all NGons, even when they’re selected. To help improve the visibility of the selected faces, you can switch viewport shading to Wireframe mode by using the Shading drop-down list from the 3D view toolbar. ▶2.32

When modeling complex objects (e.g., organic models), you’ll often need to select an edge loop-that is, a set of connected edges running sequentially in a line across the surface of a model. Sometimes you’ll need a complete edge loop, but other times you’ll need only a fraction of it. To select a complete edge loop in Edit mode, select just one edge from the model, and then choose Select > Edge Loops from the 3D view menu. This selects the complete edge loop, which passes through the selected edge. ▶2.33

Sometimes you don’t want to select a complete edge loop but only a fraction of it. This is useful when, for example, you want to select only the front edges of a loop running vertically along a character’s face, as opposed to all edges running around the back. Blender can do this too! To achieve partial selection, choose the first and last edges of the edge loop that you need, and then choose Select > Shortest Path from the 3D view menu. Doing this selects all edges running on the shortest path between the two selected end edges. This works also for edges that aren’t in the same edge loop, but selecting edges within the same edge loop often makes the most sense. ▶2.34

Imagine this scenario. You create a plane object in the scene to act as a wall for an interior environment. Then you cut a square hole into it for a window opening looking outside. Having done this, you need to select all edges running around the window hole, to create a frame and a ledge. ▶2.35

Now maybe you could select all the perimeter edges by clicking each one or, in some cases, by dragging a rectangle selection over them. But sometimes the edges may not be so easily selectable, or maybe there are just too many edges! This is where Non Manifold selection comes to the rescue. Simply click Select > Select All by Trait > Non Manifold from the 3D view menu. ▶2.36

Choosing this option selects all the perimeter edges in the mesh-that is, all edges connected to only one face. This may select some unintended edges, so you may have to deselect some edges to get exactly the selection you need. ▶2.37

When mapping complex objects (from heads to cars), you’ll typically lay out the UVs into separate and distinct islands, using either manual methods like Mark Seam or automatic methods like Smart UV Project. Whichever way you go, UV mapping effectively inserts dummy cuts or spices into the model along the edges (UV seams), allowing the mesh topology to f latten out into a 2D space. In principle, this divides the mesh faces into separate areas, corresponding to the UV islands. ▶2.38

It’s often helpful, while modeling and mapping, to select all faces in each island-for tweaking or adjustment. You can do this easily and quickly just by selecting only one face in an island inside the 3D viewport and then choosing Select > Linked from the menu. ▶2.39

When choosing Select > Linked while in Face mode, the selection repeatedly expands outward from the selected face, and the selection stops only when a delimiting edge or condition is found. You can choose which kind of edge or condition should act as the delimiter. The delimiter is that which stops the selection expansion. You can pick this by using the Tools panel.