# Plane + Frustum Intersection

Hi,

I need some help to find the intersections, I mean (x,y,z) of the points, between a plane and my frustum.

Thank you.

A plane is infinite, and a frustum is made up of 6 infinite planes.
What x,y,z points are you after?

You’re right.
The 6 infinite planes of the frustum define a finite volume.
Now, suppose I have a box (ok, not an infinite plane), what I need is (when the box intersects the frustum) the (x,y,z) of the points which define the volume of the part of the box inside the frustum.
Do you see what I need ?

Ulf Assarsson and Tomas Möller, “Optimized View Frustum Culling Algorithms” http://www.ce.chalmers.se/staff/uffe/vfc.pdf

Thank you for your answer dUckmAnn, BUT I am not looking for a fast test inside/outside, what I need is the exact points of intersection.

The intersection between a frustum plane and your plane will either yeild, nothing, a line, or a plane.

Intersection between a plane and a frustum will give nothing, or a polygon.

This requires basic knowledge of linear algebra.

V-man

Yes V-Man, that’s what I am looking for.
Have you got an algorithm ?
A piece of source code ?
An url ?