geometry in space
Author
hi all,
i develop in opengl and a function keep these parameters:
gluLookAt( eyex, eyey, eyez, aimx, aimy, aimz, upx, upy, upz);
the param (eyex...) could be condidered as vectors with y the height in space.
then my problem is for the up vector. this function is as a camera.
then, if my up vector which place the orientation of the camera is not set correctly, the view is incorrect.
how to set this up vector correctly according to the 2 other vectors ? the camera is set at horizontal but is inclined due to the vector formed by aim-eye.
can someone help me (and almost understant what i want ?)
thanx a lot
Fratt
Remember that the second set of parameters is not a direction but a point.
i.e. ( 1, 0, 1, 0, 0, 1, 0, 1, 0 )
viewpoint in point ( 1, 0, 1 )
center looking at point ( 0, 0, 1 ), that is down vector ( -1, 0, 0 )
up direction is ( 0, 1, 0 )
The combination (cross product) of your ''up'' vector and ''forward'' vector (forward = center - viewpoint ) defines your ''right'' vector. The up vector must be provided to compute the missing vector, not the other way round.
i.e. ( 1, 0, 1, 0, 0, 1, 0, 1, 0 )
viewpoint in point ( 1, 0, 1 )
center looking at point ( 0, 0, 1 ), that is down vector ( -1, 0, 0 )
up direction is ( 0, 1, 0 )
The combination (cross product) of your ''up'' vector and ''forward'' vector (forward = center - viewpoint ) defines your ''right'' vector. The up vector must be provided to compute the missing vector, not the other way round.
This topic is closed to new replies.
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