Calculate near/far plane vertices using THREE.Frustum

Question

I need some help to deal with THREE.Frustum object.

My problem:

I need to calculate near/far plane vertices; I\'ve taken a look at these tutorials

Answer 1

Three.Frustum is not really going to help you -- it is a set of planes. The good news is your solution appears correct, but there is an easier way to think about this.

The upper right corner of the near plane is a point in camera space with these coordinates:

var ntr = new THREE.Vector3( wNear / 2, hNear / 2, -camera.near );

using your definition of wNear and hNear, which are correct.

Now, making sure that camera.matrixWorld is updated, you convert that point to world coordinates like so:

camera.updateMatrixWorld();
ntr.applyMatrix4( camera.matrixWorld );

Now, flip the signs to get the other three corners, and then repeat the calculation for the far plane.

See, you had it right; you just took a more complicated route. :-)

EDIT: updated to three.js r.66