Hello HakJak, I'm sorry about the inconvenience. I don't understand what makes this bug happen. I also used several materials with diffuse and normal textures to make the demo level and they worked well with UModeler objects as shown in the release trailer video. And I've tried to reproduce this bug using Standard shader on Unity 2017.3.0f3 but this bug hasn't happened to me. Did you also find that other materials didn't work? It would be really helpful to solve this issue if you sent me the scene file and the material and texture files used in the attached image.