The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Software » comp.soft-sys.matlab

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: view-pipeline
Replies: 0  

Advanced Search

Back to Topic List Back to Topic List  
Andreas Ruf

Posts: 11
Registered: 12/7/04
Posted: Mar 6, 1997 6:58 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

I've some trouble with 3D-plots 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!

v = O P a

However, as soon as I change to:

v = O P inv(H) H a

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

It seems to be that there is another transform or another V
in the pipeline!

v = o P V a

How is the projection actually realized ?


Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.