Use this scene to check your models. After uploading, place your asset into this scene by clicking on it, so it loads at the center of the scene instead of dragging it. Pay particular attention to the scale, dimensions, rotation, and orientation of your model. Ensure you are using OpenGL normal maps and check the orientation of polygon normals. Check the brightness of emissive materials and light sources in the rendering. Note that the Subdivision Surface modifier - Level Viewport is allowed a maximum of 1.