So I'm trying to kit bash in Asset Forge (AF) using models from Synty. They provide the FBX or OBJ in their source files for each of thier packs so naturally I copied the OBJ files into ~/AF_2.0d/Collections/Synty and they appear in AF but with crazy scaling and a single white material. I've fixed the scaling issue using the meta.ini which was simple enough, however, the material problem has me stuck. Synty's source files don't include a MTL so this is obviously the root of the problem. However, they do include a Textures folder with a bunch of PNG files so this was the next logical step to try.
I imported the model into Blender and under Shading, I added the .png associated to the model then exported the model from Blender as an OBJ which also generated an associated MTL file. Great I thought, so I added these to a collection in AF, went to import and it appears fine with the correct material until I actually add it to the scene. The PNG tiles as the material as in the screen shots below, which is no more progress than I had before. Any thoughts or ideas to try next? I'm definitely out of my scope here.

This is the asset before I actually add it to the scene by left-clicking.

This is after I left click to add it to the scene.

Synth game assets use a texture map which is not compatible with Asset Forge, Asset Forge overwrites an UV map. Custom blocks are meant to work with both the Kenney assets plus custom made models - but not all models that can be downloaded on the web unfortunately.

However! If you don't mind this workaround, it might allow you to start 'texturing' your models - Go into blender and on each model, create new Material slots (woodenPK, metalPK, stonePK, GlassPK) Then, if you look at your particular UV map for the blender file, you'll see that some of the model takes up a section of the UV. Grab up each section of the model, and ASSIGN those vertices to that particular material. Then save as OBJ file. If you use a uniform format for the materials of each structure model, you SHOULD be able to affect each one. ALSO!!!!

I have found that importing each model into Blender as 1.2 scale makes each wall approximately 3 units. This makes things a bit easier to work with for me and the gridding.