AnisotropicTM Filtering flavors
Talisman™ Escalante™ Anisotropic™ filtering
- approximates direction of maximum anisotropy using derivatives
- progressive approximation - from square pixel to:
- a parallelogram (maximum direction error 7%)
- a rectangle (maximum shear error ---> 90 degrees?)
- even number of trilinear samples - end samples are weighted
- ignores perspective within a pixel (square pixel is really a quadrilateral in texture space)
TEXRAM Footprint Assembly
- approximates direction of maximum anisotropy using derivatives
- progressive approximation - from square pixel to:
- a parallelogram (maximum direction error 7%)
- (implicitly) a rectangle (maximum shear error ---> 90 degrees?)
- power of 2 number of trilinear samples - end samples are not weighted
- ignores perspective within a pixel (square pixel is really a quadrilateral in texture space)