So, I have created a level for my game in SketchUp 8 (2013 has this free trial thing that I can’t cancel) and textured and exported it. However, when I load the model into Unity, strange things start to happen. While some of the surfaces are textured correctly, the rest are untextured, despite the appropriate material with the texture being there. Reapplying the material manually yields no results. Also, in the editor properly textured surfaces are cut off so I can see inside the model, while this is not the case with those whose textures fail to load for some reason. So what should I do? Is it a Unity or SketchUp problem? Should I try an alternative way to make my levels (I’m going for a few rooms connected with hallways sort of thing)? Looking forward to your replies.
P.S. I’m gonna go to sleep now, so don’t be surprised if you don’t see me replying for a few hours.
I don’t personally export raw geometry straight into unity from sketchup nor do i use it that often for that matter, but i’ll try to lend a hand.
Untextured surfaces - A decent intermediary 3d package like maya/max or even blender would help you identify material properties and make sure each material is assigned to the correct surfaces. Your Shaders may be correctly set up, but materials not correctly assigned. I know its a pain but with such a short pipeline there is no room for identifying problems within the models’ sub-material set up.
Surface transparency - If the surfaces are completely transparent, sketchup may have reversed these faces which means they are culled inside unity for the sake of performance. You should go back into sketchup and see if these faces are, in fact, properly aligned. It could also be an issue at shader level - Are you using alpha transparency with these materials? Sketchup tends to use alpha channels as transparency which have been ported across to unity… again, its just a guess.
Alternative building methods? - For interior modelling you really want clean, quad geometry that is both uniform and easily edited for later art-passes (should you wish to do them). Sketchup isn’t to bad in this case, however! One wrong move can cause sketchup to reverse faces, clip geometry and generally go haywire. Again, a more robust solution would be a decent 3d package built for purpose (blender/max/maya/wings/soft image etc.). On the other hand, there is an asset called “probuilder” on the asset store which offers easy level design whilst keeping things neatly snapped to a grid. Its not really any good for high poly, static geometry or organic models but then again, neither is sketchup.
So to recap - Go over your material id setup, check face alignment and your material setups.
I have just opened up the model in Blender and found a suspicious material called “material” applied to all surfaces. When I removed it, everything turned pink. As for the surface transparency, it isn’t a problem. Since it is a room/hallway/whatever, I want the interior surfaces textured. I just noticed that textured surfaces are transparent from the outside, allowing me to see into the room as if it wasn’t there, while that is not the case with untextured surfaces. In playmode, everything is still there. I just wanted to point out that difference between properly and improperly textured surfaces. As for Blender/Maya/etc, I’ve always thought them to be a bit of an overkill for the simple things I need. ProBuilder is too expensive, although it sounds interesting. Also, a noob question. How do you check face alignment?
I imagine that is the stock sketchup material, its the white material seen when you first start modelling. If it still exists somewhere in the model, it will be ported across to any 3d application. That’s the only reason i could see any rogue materials popping up.
These are almost certainly back faces. If you want this problem corrected-
Identify the problem faces
Open the model in sketchup
Right click the offending faces and select “reverse faces”
if it is a backface, the face will turn white and un-textured (the problem is corrected now, just re-texture the surface)
If the face isn’t a backface, it will turn purple and un-textured. (Hit Ctrl-z)
There is no intuitive way to normalize faces en-masse, so this will have to do for now.