In this tutorial you will learn how to create a shadow map on your sculpties that you can use to create high-quality textures for your sculpts.
Texturing with Shadow Maps
For some sculpties, slapping on a tileable texture from your inventory might work well enough.
Often, however, it looks better if you create a texture specifically for your sculptie. Sometimes this is even necessary to get the look that you want. The trouble is, how do you make a texture that fits your sculptie exactly?
I’ve often seen people use a colored and numbered grid to map out the general location of certain parts of a sculptie, then match it to the same grid in 2D format. While this method has its place, it can get pretty tedious.
There are features in Blender that will help us make textures for our sculpties relatively quickly. In this tutorial we’re going to focus on baking ambient shadows, which is probably the fastest and easiest to understand method available in Blender.
In this tutorial, I ask that you have your screen split in half and one half switched to the UV/Image Editor.
Ambient Occlusion
Before we begin, I want to change the draw type in the 3D View to Textured. Find the small menu to the right of the Mode menu (marked in red – click the image to enlarge) and switch the draw type to Textured. If your sculptie is currently assigned a UV texture (such as a sculpt map), you’ll see that texture placed onto your mesh in the 3D View.
If you’ve ever worked with other Blender sculptie templates, you may already know how to bake textures onto an image. However there are other types of images we can bake. The type we’re going to bake now is Ambient Occlusion – or global shadows.
First we want to assign our mesh to a new texture. If you have multires on your mesh, you need to switch to Level 1 or Apply Multires before you change textures. Then go into edit mode and select All, by tapping A until all the vertices are yellow and the faces pink. Then in the UV/Image Editor, go to the menu Image > New. Make a new image that’s 256 x 256 or 512 x 512. Hit OK. (If you switched to Multires level 1, you can now switch back to level 3.)
Now go to the Scene > Render Buttons (marked in green – click the image to enlarge) and then find the Bake tab (blue) and change the bake type to “Ambient Occlusion” (yellow) and hit Bake. Wait a few moments for Blender to bake shadows onto your image. Save the image as something meaningful.
Usually this shadow map gives you enough ‘landmarks’ on the texture to be able to paint a texture that exactly fits your sculptie. Just use your favorite image editing software.
Previewing Your Texture
Testing your texture before uploading is incredibly easy. Simply save your new texture right over the file you saved from Blender. Then in Blender, reload the texture file by selecting Image > Reload in the UV/Image Editor.
Your new texture will now be wrapped around your mesh. If something’s wrong, but you’re not sure where it is on the image, you can select the faces on your mesh and it will highlight them in the UV/Image Editor.
Another Texture
Maybe you’d rather keep the original shadow map or maybe you have multiple texture that you want to preview, like if you’re doing multiple recolors. You save these textures separately and then open them in Blender to preview on your mesh. Go to Image > Open. Find the texture you want and hit “Open Image.”
Then in Edit Mode swith to Multires level 1, select all your vertices, and find the drop-down menu next to the UVs Menu (marked in yellow). Click the small button with the arrows and select your new image. From this menu, you can also switch back to your old image, or to any image currently opened in Blender.
Multi-Sculpt Bake
If you have more than one sculpt mesh in a single .blend file (see how here) then each mesh may effect the shadow baking of the others.
If you look at the image to the left (click to enlarge) you can see how the smaller mesh has created a dark shadow on the larger one.
Sometimes this is desirable, such as when you want a drop-shadow look on your group of sculpts, but if you’d rather they affect each other less or not at all, move the meshes away from each other before baking.
