Up until now, we have set just one UV layer whose name is, by default, UVMap (go to the Object Data window and look under the UV Maps subpanel):
The UV Maps subpanel with the UV Map coordinates layer
Actually, in Blender, it is possible to set more than one UV coordinates layer on the same object in order to mix different UV projections that can eventually also be baked into a single image map.
The names of the UV layers under the UV Maps subpanel are important, because they specify which one of the projections a material has to use for the mapping of a texture. By clicking on the + icon to the side of the UV Maps subpanel, it is possible to add a new UV layer (whose name, in this case, will be UVMap.001 by default; of course it's possible to change these names by using Ctrl + clicking on them and typing the new ones).
We are now going to add a new UV layer to the Gidiosaurus object:
- Ensure that the Gidiosaurus object is selected and go to the Object Data window under the main Properties panel to the right-hand of the screen.
- Go to the UV Maps subpanel and click on the + icon to the right-hand side of the names window; a new UV layer is added to the list, right under the first one, and its name is UVMap.001 (in case you don't see it, it may be because the window is too small; just put the mouse cursor on the = sign at the bottom of the window and drag it down to enlarge it):
The new UV coordinates layer
- Use Ctrl + left-click on the UVMap.001 item and rename it as UVMap_scales. Then, press Enter to confirm.
Now we must set the projection of the UV layer:
- Go into Edit Mode, switch to the Face selection mode, put the mouse pointer on the mesh, and press the L key to select all the faces of the skin of the Gidiosaurus mesh.
- Go to the UV/Image Editor window, select all the visible islands and unpin them (Alt + P).
- Click on the Image item on the toolbar and select the Open Image item in the pop-up menu (or else, put the mouse cursor in the UV/Image Editor window and press Alt + O); browse to the
texturesfolder and load thescales_tiles.pngimage. - With the mouse pointer in 3D view, press U and from the UV Mapping pop-up menu, select the Cube Projection item.
- In the UV/Image Editor window, select all the islands and scale them 5 times bigger (A | S | 5 | Enter):
The Cube Projection mapping
- Go out of the Edit Mode and into the Properties 3D view sidepanel, enable the Textured Solid item under the Shading subpanel to see the result of the unwrapping in the 3D viewport:
The scales_tiles.png image mapped on the model using the second UV coordinates layer
At this point, as you can see in the UV Maps subpanel, the Gidiosaurus object has 2 different UV coordinate layers, UVMap and UVMap_scales. We will use the UVMap_scales layer to map the scales image texture on the body and thereby to bake it on the first UVMap layer; this will be the one we'll use in the end for the rendering of the model. However, we'll see this in detail in the texturing and baking recipes.
Repeat the process for the Armor.
- Add a new UV layer and rename it UVMap_rust; go into Edit Mode, select all the vertices and all the islands in the UV/Image Editor window, and load the
iron_tiles.pngimage. - Switch to the Face selection mode, and in the 3D view, press U and select Reset (the last item) from the pop-up menu. Then press U again, and this time select the Cube Projection item.
- Go out of Edit Mode.
As you can see, there are a few visible seams. This will be easily fixed during the texturing stage, but for the moment we are done:
The second UV coordinates layer for the Armor