Chris
thanks thats interesting to know. My opengl is very rusty but I
know or at least knew the general philosophy.
My background is Computer Vision so I tend to think in terms of an
explicit camera/projection matrix which isnt necessarily modelled or
exposed directly as such in many 3D graphics packages but in the CV
community solving for and using the matrix is one of the central
things we do.
Where these two worlds of graphics and computer vision cross is
Augmented Reality. QC has been used for Augmented Reality - I see
George posted a cool video a couple of years back
http://vimeo.com/2375562
Were you involved in that at Kineme?
I wondered how AR alignment of virtual objects and live cameras is
achieved within the QC framework - do you have a sketch of the general
approach?
regards
Mark
Quoting Christopher Wright <[email protected]>:
I was trying to guess the parameters of the matrix as if it
was a camera. how far did people get in reverse engineering it? Is
there really two seperate matrices?
smokris and I gave the camera location -- I'm not sure what else.
It's a single line of code to ask GL for it. It's not top-secret or
anything, it's just not simply in code anywhere for reference (it's
synthesized in a few steps during initialization). I don't think
we want people building matrix-specific compositions because that
breaks down under a number of circumstances.
The 2-matrix setup is actually due to OpenGL (GL_PROJECTION_MATRIX
and GL_MODELVIEW_MATRIX) -- QC simply followed that model.
Projection isn't used much at all (nothing changes it), ModelView is
what gets modified all the time (every X/Y/Z Position/Rotation
input concatenates a new matrix on it, along with other
transforming patches doing the same thing).
--
Christopher Wright
[email protected]
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