GPU culling using compute
In the previous section, we demonstrated how to perform back-face and frustum culling on meshlets. In this section, we are going to implement frustum and occlusion culling using compute shaders.
Depending on the rendering pipeline, occlusion culling is usually done through a depth pre-pass, where we write only the depth buffer. The depth buffer can then be used during the G-Buffer pass to avoid shading fragments that we already know are occluded.
The downside of this approach is that we have to draw the scene twice and, unless there is other work that can overlap with the depth pre-pass, have to wait for the depth pre-pass to complete before proceeding to the next step.
The algorithm described in this section was first presented at https://advances.realtimerendering.com/s2015/aaltonenhaar_siggraph2015_combined_final_footer_220dpi.pdf.
Here’s how it works:
- Using the depth buffer from the previous frame, we render the visible objects...
