I'm a little confused here as to how each of the mappings produces the intended effect on the image. On the left, how exactly does perturbing the surface normals cause the shadows and ridges that mimic a bumpy surface?
Similarly, on the right, by offsetting the positions of the triangles according to texture values, are we saying that some triangles are pushed into and out of the sphere? How is this accomplished with a texture map, are we saying that, for example, a darker color on the texture map would mean offset the triangle inside towards the center of the sphere, and a lighter color on the texture map means push the triangle outwards from the surface of the sphere?
I'm a little confused here as to how each of the mappings produces the intended effect on the image. On the left, how exactly does perturbing the surface normals cause the shadows and ridges that mimic a bumpy surface?
Similarly, on the right, by offsetting the positions of the triangles according to texture values, are we saying that some triangles are pushed into and out of the sphere? How is this accomplished with a texture map, are we saying that, for example, a darker color on the texture map would mean offset the triangle inside towards the center of the sphere, and a lighter color on the texture map means push the triangle outwards from the surface of the sphere?