Hello Could someone please explain me how can I build a frustum from a polygon(actually a rectangle), or maybe point me to some docs which explain the maths behind building a frustum from a polygon. Thanks in advance, Oscar

What do you mean build a frustum from a polygon? Do you mean you want a projective transformation for the view frustum which will render into a specific quad on the screen? Or just build a geometric object?

"Math is hard" -Barbie

Hi

Hope this clariffy my question:

I am trying to code a Function for my portal engine which define my frustum clipping planes from my portal shape which is a simple rectangle.

Thats why im askig how can I build a frustum (clipping planes) from a poly(my portal)

Regards,
Oscar

Take your rectangle and your viewer''s position.
This builds a "pyramid". So you''ll have to take your position and
for every edge of the rectangle define a plane.
You''ll get 4 planes + the plane which is defined by your rectangle. Whatever lies within these planes is visible from your viewer''s position through the portal.
Wanna all the math ?

Hi

Thanks for your help, I got it working now! : )

Regards,
Oscar