Please correct me if an assumption I have made is incorrect, or if I have missed something. When OptiX is traversing the BVH, it determines the geometry for which the ray intersects the geometry’s AABB. It then calls the geometry intersection function to see if there truly is an intersection between the ray and the geometry itself. This causes an issue when the geometry does not completely fill its bounding box.
The example is when a sphere and box are near each other and their bounding boxes overlap. If the box geometry is outside of the sphere but contained in the sphere’s AABB, then the box will not show up in front of the sphere even when it should. (See the attachment for a clearer example where the box should be seen by the center ray but is not).
Is there a way around this issue, or is this something inherent in the BVH algorithm?