pjcozzi
commented
7 years ago To improve this:
- Double check that OrientedBoundingBox.intersectPlane is correct. It probably is, and the screenshot above is probably because the view frustum is huge and this is the classic problem where the bounding volume is outside at the frustum corners but the algorithm still reports "intersecting."
- Try Correct Frustum Culling. After the 6 plane test reports intersecting, test all the corners of the frustums against each of the planes of the bounding volumes.
- Note that the larger the bounding volume (which is common in Cesium terrain and 3D Tiles), the more likely the plane test is to return a false intersection so I suspect these extra checks will more than pay for themselves in fewer draw calls.
- Given the increase cost, #4787 could be a big win.
- Implement for both OBBs and spheres, and profile for both terrain and 3D Tiles.
austinEng
lilleyse
The current OBB vs plane algorithm is an approximation that works best with more evenly-sized dimensions. As a result we sometimes see results like below, which cause tiles to be selected that aren't actually visible.