Parallax mapping is the next step on from normal mapping, and gives the illusion of depth in a 2D surface from a texture. It's used in great effect with stony floors in Kameo and Lair. This ATi presentation on page 9 has an excellent example too. In this case I'm thinking it could give the illusion of depth needed to a flat, blurred texture that approximates the spokes seen at speed.
That is not so my friend. Photo texture will not look 3d from angle but the wheels look 3d. You can see light and shadow changes and also curved shape of spokes from different angles.
This is a 3D wheel. This is what it looks like in videos. You can see curved spoke and occlusions. With photo-texture spokes will not have these curves and occlusions from this angle.
http://images.gamersyde.com/gallery/public/5975/1316_0001.jpg
So in order for it to be 3D, PD HAVE to say its 3D?
Those are YOUR words not mine..I just asked a simple question, a yes or no is sufficient.
The point, which apparently flew over your oblivious head, is how can one be so sure that it's 3D from a still screenshot unless there is some other proof?
)so in order to do parallax mapping you have to do normal mapping? sorry to take this thread off topic.
It can be done even without, but if you don't have a local normal (typically coming from a normal map) you need very highly tessellated meshes to work with it.
Too bad that when you are already rendering loads and loads of triangles then you don't need to fake geometric details anymore, thus no parallax mapping is needed.
I guess the final answer is: parallax mapping only makes sense if used in conjunction with normal mapping
Yes, I would call it a trade off between performance and memory.
