OBB Frustum::MinimalEnclosingOBB(float expandGuardband) const
{
assume(IsFinite());
assume(front.IsNormalized());
assume(up.IsNormalized());
OBB obb;
obb.pos = pos + (nearPlaneDistance + farPlaneDistance) * 0.5f * front;
obb.axis[1] = up;
obb.axis[2] = -front;
obb.axis[0] = Cross(obb.axis[1], obb.axis[2]);
obb.r = float3::zero;
for(int i = 0; i < 8; ++i)
obb.Enclose(CornerPoint(i));
// Expand the generated OBB very slightly to avoid numerical issues when
// testing whether this Frustum actually is contained inside the generated OBB.
obb.r.x += expandGuardband;
obb.r.y += expandGuardband;
obb.r.z += expandGuardband;
return obb;
}
