At this point we can (if desired) lookup pixels from a "texture" to cover the 3D model, mix colours together, & allow closer triangles to obscure further ones. Typically we store the depth of each pixel in a "depth buffer" to facilitate this depth-testing work, though early game consoles couldn't afford enough RAM for that. So somehow it made sense to sort the triangles every frame instead, which isn't exactly fast! 3/3 Tomorrow: Lighting!