Home/ Questions/Q 7437069
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-29T10:20:27+00:00

When bounding box’s all 8 vertex is out side the frustum, it won’t be

  • 0

see

When bounding box’s all 8 vertex is out side the frustum, it won’t be rendered.
But if sth happened like shown above. That object should be in the display list. Any idea?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Because you are calculating the intersection as if the box is bunch of points, instead of a bunch of lines. This is how I do it in pseudo-code:

    inter = Inside
for ( plane : frustum ) {
    verts[2] = findOpposingPointsMostPerpendicularToPlane( box, plane )
    near = plane.signedDistance( verts[0] ) > 0.0
    far = plane.signedDistance( verts[1] ) > 0.0

    if ( !near && !far )
        inter = Outside
        break
    else ( near ^ far )
        inter = Intersecting
}

    If your box is an AABB, you create a static array of vertex indices for findOpposingPointsMostPerpendicularToPlane() and then map to them using the sign of the plane normal components.

    • 0