3ds max Polygon Modeling Branching with Editable Poly Extrude It has no thickness, but if I want the rendering to look realistic, then I should model the object to some sort of physically plausible structure or form. And that means I should use an actual sheet of glass that has some thickness and not just a flat plane. So in order to do that, we can use the Extrude tool, but there are a couple other things we need to look at first, mainly there are a lot of excess vertices on this that we can’t even really see right now. So we need to investigate before we do a lot of things in 3D, and this time we need to investigate the vertex count, so I’ll choose Vertex Sub Object Mode, and look at this in the front viewport, go to Front with Alt + W, and we’ve got all these points, vertices, all around, as selected object, and those are all excess, we want to get rid of those, so we’ll take care of that in the following movie. We’ll exit out of Sub Object Mode, and that’s how to use Extrude to create an extension or depression in a surface.