billboarding

Good tutorial here: http://www.lighthouse3d.com/opengl/billboarding/

dont know how fast this is, but it works fine for me:

(i assume the z/front vector is the direction of the beam and y/up is its normal)

vec3 tmp=camera.position - billboard.position;
billboard.right=cross (tmp, billboard.front);
normalize(billboard.right);
billboard.up=cross(billboard.front, billboard.right);

either use it for the transformation matrix or to calculate the 4 corners. what this should do is aligning the billboards normal so it will intersect with your cameras view direction which should make it face the cam with its while width.

(you might have to change the order of some vectors in the cross products)

hi! thanks for all your posts. I am now ... ummm ... parsing them. The only problem most of the times, that the game has a rotateable lasergunturret (i am not so sure about the word, whatever), so the direction of the laserbeam is not always on the negative Z axis.