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viewpipeline
Posted:
Mar 6, 1997 6:58 AM


I've some trouble with 3Dplots in matlab, in particular when Im given the perspektive 4x4 transform P directly by view(P). How does the viewing pipeline actually work. What I understood sofar, that given a point A=(x,y,z) its homogenious coordinates a(x,y,z,1) are multiplied by P, and then a orthographiq projection via
O = 1 0 0 0 0 1 0 0 0 0 0 1
is done to obtain homogeneous screen coordinates, that are finally (u, v,w) displayed by u/w, v/w! Summarizingly
u v = O P a w
However, as soon as I change to:
u v = O P inv(H) H a w
with P'= P inv(H) and a' = H a, and setting(view(P') and plotting a' the projection should remain the same, is however distorted significantly.
It seems to be that there is another transform or another V in the pipeline!
u v = o P V a v
How is the projection actually realized ?
andreas



