Multiple Materials

Most objects are assembled so that they can be modelled in parts, each part being of a different material.

On some occasions it may be useful to have an object modelled as a single Mesh, yet exhibiting different materials. This is of course possible. Consider the mushroom in Figure 36. It is a single mesh, yet we need to assign two materials, one for the stem, one for the cap.

Figure 36. Mushroom Mesh

Figure 37. Mushroom with one material

First, create a creamy stem material of your choice, and assign it to the whole mushroom, as you normally would. (Figure 37).

Figure 38. Mushroom with cap vertices selected

Now in one 3DWindow enter EditMode for the mushroom and select all the vertices belonging to the cap (Figure 38) and, in the Multiple Material buttons in the Mesh Edit Buttons (F9) press New (Figure 39).

Figure 39. Adding a new material to the mesh

Now the mesh has two materials (the label now reads 2 Mat: 2 meaning that material number 2 out of 2 is active). The selected faces are assigned to this new material once you press the Assign button, the unselected faces keep any previous material assignment.

You can check which faces belong to which material by using the Select and Deselect buttons and switch among materials by using the Mat: NumButton. You can have up to 16 materials per mesh.

Both mesh materials are anyway instances of the same material! So, keeping the material you want to change active, switch to Material Buttons (F5). Here you will find a similar "2 Mat 2" button. The material now has two users, indicated by the blue color in the name of the material, and the number button showing "2" (Figure 40).

Figure 40. Multiple user material

Click on the "2" and confirm the OK? Single user question. You have duplicated the material. The original one is still called "Stem" and the duplicate is "Stem.001". Rename it to "Cap".

You can now edit the material as needed to obtain a nice looking cap. (Figure 41).

Figure 41. Mushroom with two materials.

TipTextures
 

If your material uses textures then they stay linked even after you make the material single-user. To have unlinked textures, so that you can edit the two materials textures separately, go to the TextureButtons for that material, and make the texture single-user as well.