Texture mapping fails for some loaded FBX files
I am still working on my game with my custom game engine and I still make good progress. One of the topics I am currently working on is a content preprocessor. The aim of this stand-alone tool is to read popular file formats and to convert them into file formats I designed by myself which I am going to use in my game (engine). I wrote a slim C++ application using the official FBX SDK from the Autodesk developers to read FBX files and extract the information I need. The result is written using the custom file format I mentioned.
Most things work perfectly. However, I encountered some problems with models I bought online as you can see in the image below. For example, the upper part of the chair on the left side is not correctly triangulated and the textures are sometimes wrong (see lower part of chair). The right part of the bed should also have a different color.
The assets looked perfect in the Unity Asset Store, so I am wondering, what I did wrong. Is there some sort of geometric or texture information hidden in some FBX nodes I did not see? Does Unity store additional mapping information in other files, like the *.prefabs files?
I have this issue with several assets I bought. Some other assets work perfectly, so I highly assume I forgot something and did no general mistake.
Any hints would be great!
I finally found the solution to my problem. I did not have any geometric issues, but only a texture issue. I used the V coordinate I've read from the FBX file. However, for some meshes I had to use "1.0 - V" instead of just using the V coordinate. I adjusted my content importer so it mirrors the V coordinate for these models and now everything looks fine. :-)