ozone01

04-16-2003, 03:54 AM

Hi,

I've got a question about some parameters in the projectionmatrix.

A typical call to glFrustrum gives you a matrix like this :

|E 0 A 0|

|0 F B 0|

|0 0 C D|

|0 0 1 0|

My question is about A and B. In most cases these will be 0 since left,right and top,bottom are the same except from the minus sign.

But i work with a matrix i calculated from a camera callibration. And in this matrix those values aren't zero.

I know these values stand for the optical centre, but what is their actual effect on the view i get? When i vary them manually my camera seems to move but the perspective doesn't change the way you would expect it to.

Any help would be much appreciated http://www.opengl.org/discussion_boards/ubb/smile.gif

jo

I've got a question about some parameters in the projectionmatrix.

A typical call to glFrustrum gives you a matrix like this :

|E 0 A 0|

|0 F B 0|

|0 0 C D|

|0 0 1 0|

My question is about A and B. In most cases these will be 0 since left,right and top,bottom are the same except from the minus sign.

But i work with a matrix i calculated from a camera callibration. And in this matrix those values aren't zero.

I know these values stand for the optical centre, but what is their actual effect on the view i get? When i vary them manually my camera seems to move but the perspective doesn't change the way you would expect it to.

Any help would be much appreciated http://www.opengl.org/discussion_boards/ubb/smile.gif

jo