3ds max Polygon Modeling Extruding a planar surface to a closed volume . From the modifier list, choose cap holes and now we have a perfect pane of glass that fits precisely into the extruded depression in the monitor chassis. We can finish this up by just reconverting it to editable poly and that will bake the cap holes modifier in. Right click, convert to, convert to editable poly. And then exit out of isolate selection mode and we’ve completed the monitor glass that fits precisely into the monitor chassis. We can maximize the perspective view with alt+w. Select that monitor glass, right click to get at its object properties, and turn on the see through property. Click okay. And it looks a little bit funny with those flickering polygons but if we get in really close here on the lower right corner and select that monitor glass and maybe move it around a little bit, we can move it forward in the y axis. So that would be giving it a lower value. So we can click and drag on the transform type in area and move that back and forth to verify that it’s actually perfectly inset within that depression. Alright, great so I’ll undo that with control+z and then zoom back out with the z key and if we want, we can turn that see through off again. Right click, object properties, and disable see through. Alright, that’s how to convert a planar polygon surface into an object that actually has some thickness using the tools in editable poly and the cap holes modifier.