how can I project a 3dpoint correctly when its z is negative?
I would want to visualize correctly
a polygon also when is behind the observer
es:this this example produces an incorrect result.
Distance=2.56f // Distance of the observer
x=-0.5f // 3d x
y=-0.5f // 3d y
z=-2.50f // 3d z
Inverse=1.0f/(z+Distance); // reciprocal
Xp=(x*Distance)Inverse; //x projected
YP=(yDistance)*Inverse; //y projected
thanks in advance
[This message has been edited by jeppa (edited 10-04-2001).]
As I understood you do the projection yourself already in eyespace. So any point with negativ z-value is behind the viewer. Your problem seems to be the “Inverse = 1.0f/(z+Distance);”. Try to do a “z = (float)fabs(z);”(or something like that) before you calculate the “Inverse”.