What’s so hard? (“unsolved” problems)
geometry creation - authoring is still hard
geometry animation - authoring uses curved surfaces, hardware accelerated rendering uses triangles
geometry transmission - triangle data swamps the bus
better texture filtering - is trilinear good enough? (hint: no)
more textures - texture-based lighting & shading is gaining momentum
better lighting and shading - vertex lighting, and Gouraud and Phong shading are showing their age
parallel rasterization - more pixels more often
pixel rendering bandwidth - getting calculations into memory
anti-aliasing - looks fine, but costs too much to do well