03/13/2003
15-462 Graphics I
14
Other Operations
•Pixel shading (Gouraud)
–Bilinear interpolation of vertex
colors
•Depth values (z-Buffer)
–Bilinear interpolation of vertex
depth
–Read, and write only if visible
–Preserve depth (final orthographic
projection)
•Texture coordinates u and v
–Rational linear interpolation to avoid
distortion
–u(x,y) = (Ax+By+C)/(Dx+Ey+F) similarly
for v(x,y)
–Two divisions per pixel for texture
mapping
–Due to perspective transformation