KruzeS on 31 July 2007
| alpha_dk said: However, in the documentation and in common vernacular it is still known as a "4-dimensional" point. |
Wrongly so, because they are 3D homogenenous coordinates.
And they're used everywhere because they: a) simplify perspective projection (essential for 3D); b) facilitate the composition of affine transformations (like rotation, reflection, scaling, shear and in particular translation); c) allow the representation of points at infinity.
Direct3D most definitely uses them, OpenGL since its inception 15 years ago, I'd bet every 3D hardware uses them. For 3D (homogeneous coordinates), for rotations (quaternions), for colors (with alpha) - 4 coordinate vectors are the norm.
4D is nothing but marketing speak.
Reality has a Nintendo bias.
