Volume rendering and Ray Tracing are SLOW
Volume rendering and ray tracing are painfully, ridiculously slow. Here is how to replicate.
- ParaView 5.11.1, Linux, builtin server.
- Settings/ Advanced/ RenderView/ Show Annotation. All we need is the framerates.
- Open g1s1-10fps.e.16.[0-15] Apply. Color by ids. Note dataset is only 20,000 cells and 28,000 points. Not sure if that is relevant.
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Frame rate on my workstation is about 560 fps. Way nice.
- Volume Render.
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Frame rate on my workstation is about 16 fps. Usable, but ouch.
- Turn off Volume Rendering, turning on Surface. Turn on Ray Tracing.
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Frame rate on my workstation is about 22 fps. Usable, but ouch - especially as we are only ray tracing the outside surface.
- Change Surface to Volume Rendering.
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Frame rate on my workstation is about 3-4 fps. Not really usable.
For real datasets with many, many more cells this would be basically unusable. I believe we would multiply time spent by the area (which isn't impacted by cell count) and depth (which would be impacted by cell count).
The other issue is that these renders happen every time someone changes something in state, such as changes visibility of filters.