ABSTRACT
Next, activate viewport rendering by changing the Viewport Shading mode to Rendered. This is accessed via the 3D view menu. ▶5.4
Viewport rendering is computationally expensive. It easily causes major system slowdowns. A simple way to mitigate this is to use viewport rendering only for a smaller, secondary 3D viewport-as opposed to the main 3D viewport. ▶5.5
Texture painting lets you paint weighted brushstrokes and images onto 3D models directly in the viewport, using either the mouse or the pen tablet. It makes texture creation simple and more intuitive and is especially useful for hiding texture seams. Not only this, but you can paint on layers too, just like painting with Photoshop or GIMP-stacking up brushstrokes on top of each other! This means you have
access to a largely nondestructive texture painting workflow directly in the Blender interface. By painting onto separate layers, you can carefully organize and isolate specific brushstrokes and pixels. Texture painting, however, is more feature filled with the Blender Internal engine, as opposed to Cycles. Consequently, before texture painting objects, activate the Blender Internal renderer from the application toolbar. ▶5.6
To get started with layered texture painting, display the N Panel inside the 3D view. From the Shading section, select GLSL from the Shading drop-down. Using GLSL mode, you can preview texture painting work using the Texture and Material viewport shading modes. The default Multitexture mode will not display texture paint edits. ▶5.7
it some UV mapping, remove its materials, and then enter Texture Paint mode by choosing Texture Paint from the mode drop-down. ▶5.8
By opening the Tools panel, you can access the texture-painting tools and their associated settings. Select the Tools tab, and a “Missing Data” warning appears. This warning indicates that no paint layers (slots) exist and the object has no material assigned. You can fix this in one operation by creating a new paint slot-and Blender does the rest! To achieve, this click the Add Paint Slot drop-down button from the Tools tab. Then choose the kind of slot to add. The slot type specifies the material channel to which your brushstrokes are appliedsuch as Diffuse, Bump, Glossiness, and so on. In many cases, the initial slot will be Diffuse Color, allowing you to paint color data into the main material channel. ▶5.9
The Add Texture Paint Slot dialog appears. Use this to specify the pixel width and height of a new diffuse texture. Clicking OK creates a new texture and assigns it to the Diffuse slot for the currently active material. If the object has no material, Blender automatically makes one. If the texture is an initial background (or base) layer, then you don’t need to create an Alpha Channel. ▶5.10
list of available paint slots (layers), each of which maps to a texture for painting. The slots correspond to textures assigned to the material for the selected object. These can be viewed from the Textures tab in the Properties panel. ▶5.11
Now select a brush to use for painting (like the Texture Draw brush) from the Tools tab. All brushstrokes are applied to the selected slot from the Slots tab. The Radius and Strength settings control properties for the brush, and these can be linked directly to the pressure sensitivity of your pen tablet through the Pressure button. ▶5.12
Now here comes the clever layer painting part! Create a new layer by switching to the Slots tab and clicking the Add Texture Paint Slot drop-down button. From here, choose Diffuse Color. Then, select a new diffuse texture. For the new layer, ensure that Alpha Channel is activated. ▶5.13
with an Alpha (A) of 0. This fills the new texture slot and texture with transparent pixels, showing the layer beneath. ▶5.14
Now select the newly created slot from the Slots tab, and continue the painting process as before. This time, all new paint strokes are added to the new slot and are layered on top of the original layer. You can easily toggle layer visibility on and off using the visibility icon from the Slots tab. And you can also change the Blend mode of the selected slot, using the Blend Type drop-down. The Blend modes work much like Photoshop or GIMP blend modes. ▶5.15
Imagine this: You’ve invested time and effort painting layer after layer of brushstrokes, and your model is finally looking great. But now you need to flatten all layers, exporting the consolidated paint to a single, diffuse texture-the kind used for any real-time game engine. How can you do this? Blender doesn’t have
a convenient Flatten button. The way to achieve layer flattening is to use texture baking. To start, use the UV Image Editor to create a new texture that will contain the flattened output. Select Image > New Image from the file menu. Then, create a new texture with the needed dimensions, without an Alpha Channel. ▶5.16
Next, select all the faces in your model using Edit mode, and then view your composite, output texture from the UV Editor, side by side with the model. ▶5.17
Switch to the Render tab from the Properties panel. Scroll down to the Bake section. From Bake mode, choose Textures. Then click the Bake button. Voila! ▶5.18
Now you’ve got a completely baked diffuse texture from your painted layers, and you’ll want to export it to an external file. To do this, just choose Image > Save As Image from the UV Image Editor. ▶5.19
Here’s a great tip. You’ve created a mesh and unwrapped it (although you’ve not yet textured it), and now you’ve positioned the scene camera to get a complementary view of your work under some basic lighting. You’re now ready to make an initial render. ▶5.20
After making a full-size render from the camera using any render engine (Internal or Cycles), save the result to a standard PNG image file, using the UV Image Editor. ▶5.21 At this stage, a texture artist or a Photoshop expert may wish he or she could import the rendered image into Photoshop, paint all texture details onto the rendered image (using it as a guide) with Photoshop’s expansive painting tools, and then finally save the result, projecting it back onto the model in Blender as a final texture. Well, you can do this! Here’s how. First, create a new layer in Photoshop on top of the rendered image. This should contain all paint details to be projected back onto the model. The rendered image acts only as a background reference to guide your painting. ▶5.22
detail layer. You can use the standard Photoshop brush tools or even the Vanishing Point filter to project images into perspective on the render. Repeat this process until you get an image that looks correct for your needs. ▶5.23
When you’re done, hide the rendered background layer to reveal the transparent pixels beneath, and save the result as a transparent PNG file. This allows you to save the details painted without saving the rendered background, which was intended as a reference only. ▶5.24
Next, load the image into Blender as a texture via the UV Image Editor. Choose Image > Open Image from the editor menu, and select the PNG texture from your hard drive. ▶5.25
on your 3D model, and switch to the Tools panel. From the Tools panel, expand the External rollout, and enter the image dimensions of your saved render. In my case, it was 1920 × 1080. ▶5.26
Then click the Apply Camera Image button, and choose your imported image. When you do this, the image texture is project painted onto the model, from the active camera, and then saved to the model’s texture via its UV mapping. ▶5.27
Great! You’ve now project painted a texture onto your model. This technique makes it really easy to apply Photoshop paint work onto your geometry. In addition, you can project paint onto a model from multiple camera angles, multiple times, and on selected faces. This gives you even more control over texture-painting models. For the best results, however, project paint from orthographic views, as this minimizes texture distortion from perspective angles.
