# Billboard rotation help !

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I've been stuck with this problem for awhile... Ok I have my billboarding matrix set this way (using D3D): getRightVec().x, getUpVector().x, getForwardVec().x, 0, getRightVec().y, getUpVector().y, getForwardVec().y, 0, getRightVec().z, getUpVector().z, getForwardVec().z, 0, getPosition().x, getPosition().y, getPosition().z, 1 (and it works, it rotates to face the viewer around the y axis) UpVector is always (0,1,0) All vectors are normalized and orthogonal. Now using this matrix, how can I rotate the billboard (around the Z axis or X axis) so that it stills face the viewer ?? (like you would rotate a normal quad for instance, the only difference being that the quad always face the viewer) I tried a simple Z (or X) rotation matrix * billboard matrix. It doesn't work when I move around, it screw up the billboarding. I hope you understand.

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For what I think you want, you'll need to form a rotation matrix, the z-axis of which is the object-to-camera vector (normalised of course). Apply your rotation to this about Z, and then apply that to your object.

Ed: probably get more responses posting questions like this on the Maths forum...

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thanks for the info

I'll try this and eventually post in the math forums, even if I hate maths.

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