I’ve made a very simple building out of four planes. “roof”, and three sides. Thusly, I should be able to walk in to the building, as it doesn’t not have all four walls. Problem being, when I load it into Unity, it will only render the “roof.” The other walls render when I actually walk through them (in the game). How do I make Unity render the whole thing all the time?
If your building made of planes, you need to add “thickness”, so that you have normals facing in and out, textured planes only appear textured on the normal face. You could add a solidify modifier in blender and apply it and add a texture to both internal and external faces, recalculate normals, apply rotation and scale and reimport the model. Check in blender with the texture view and make sure it appears correctly. Also, you might need to import the textures into unity as a separate asset and add them to the materials for the object manually.