Software occlusion culling in Block Game
2 days ago
- The author developed a software-based occlusion culling system for their block game due to a weak integrated GPU (Radeon Vega 8).
- The system renders a low-resolution depth buffer (256x128) on the CPU and uses axis-aligned cubes for occlusion checks.
- It employs a mipmap-like hierarchy of subchunk occluders (from single blocks to 8x8x8 cubes) based on distance from the camera.
- Key optimizations include cheaper vertex transforms, world-space frustum culling, visible-faces filtering, and multilevel subchunks.
- The method culls 50–60% of chunks above ground and up to 95% in caves, achieving framerates above 400 FPS on weak hardware.
- Limitations: single-block occluders only work within 20 blocks, and culling weakens when the player is high above ground or near thin structures.
- Future improvements could include using 1-block-thick slices as occluders and superchunks for very high render distances.