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145

answers:

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If I have a matrix which is a combination of World*View*Projection and I multiply it by the inverse of the projection does it yield the World*View matrix or something else? If not then how can I extract the World*View matrix from a World*View*Projection matrix?

Thanks for any help :)

+8  A: 

If you multiply on the right by the inverse of Projection, you will get World*View.

If you multiply on the left you'll get something entirely different, since matrix multiplication isn't commutative.

This assumes that Projection has an inverse. Not all matrices do.

David Norman
Projection matrices usually don't have inverses since they map to a lower dimensional space.
Victor Liu
In math that's true, but in computer graphics usually the projection matrix is invertible.
David Norman