Hi, I have a very simple math question I can’t handle :
I specify my camera perspective by using
gluPerspective(fov, ratio, front, back) ;
I want to get the widht and height of my front plane using only fov, ratio, front and back, as you cans specify in a glFrustum call.
This is to perform view frustum culling using bounding spheres.
Thx in advance
Lolo
endo
2
Is this not a trigonometry question? I could be wrong but I thought I’d have a go cos I need the practice
I think height = sin(fov/2) * near
not so sure about the width, still thinking about it, but could someone confirm the height for me please?
endo
3
width = aspect * height,
but I’m less confident of this one, so if someone could check it…
I found by myself, here it is :
Width = Front * tan(Fov/2)
and Height = Width / Ratio
thx endo
endo
5
Is that the same as mine? btw, I thought the fov was in the vertical axis, is that right?
I consider it being in the X axis so that’s why tan and no sin
huh but you seem to be right, Red book says it’s fovy… I need to change my code then
Maybe simply switching Height and Width would do I bet