Texturing and UV Maps

Texturing and UV Maps

Texturing is the process of applying 2D images to a 3D model to give it color, detail, and surface properties. Without textures, a 3D model is just a gray shape. With textures, it becomes a realistic object with wood grain, fabric weave, rust, dirt, or any surface detail you can imagine. Textures are what make CG objects look like they belong in the real world.

UV mapping is the bridge between the 3D model and the 2D texture. Think of it as peeling the skin off a 3D object and flattening it into a flat rectangle. The U and V coordinates are like X and Y for the texture space. Every vertex on the 3D model has a UV coordinate that tells the renderer what part of the texture to show at that point. A good UV map has no overlapping areas and uses the texture space efficiently.

Creating a good UV map is a skill in itself. You need to cut seams in the model where the UV shell will be split, like the seams on a piece of clothing. The seams should be placed in hidden areas where they will not be noticeable. Then you unfold the UV shells and arrange them in the texture space. Some parts of the model need more texture resolution than others, like the face of a character compared to the back of the head.

PBR textures typically include several maps. The albedo map is the base color. The normal map fakes surface detail by changing how light bounces off the surface. The roughness map controls how shiny or matte each part is. The metalness map defines which areas are metallic. The ambient occlusion map adds contact shadows in crevices. Together, these maps create a complete material definition.

Textures can be painted by hand in software like Substance Painter or Mari, generated procedurally, or captured from real objects using photogrammetry. Substance Painter is the industry standard for texture painting because it lets you paint directly on the 3D model and see the results in real time with proper lighting. It also supports smart materials that automatically adapt to the shape of the model.