Figure 5.29 - Red material
However, we can create another material using the second material
index for this selected object. Each object has independent material
indexes.
Add another index for that object using the "+" button on the right. Select
an existing material or create a new one from scratch. In our case, we
can create a simple material called "Green" with a Diffuse BSDF shader
and set a green color.
Select half of your object faces, and with the index containing the
"Green" material selected, press the Assign button (Figure 5.30).