what is it about raytraced animation that makes it more expensive to update the BVH mesh vertices every frame, compared to old-school bone animation where you send the info to the vertex shader every frame?
A 3D transform is built into the BVH, which the ray follows when evaluating the BVH. This adds animation information too. The upside is i think, that the animation is evaluated on the fly, in parallel by each ray. No need to update anything on the GPU, just the timestamp.
I'll note that the above is based on an impressive paper presented at the same conference in the previous year, "Real-time rendering of animated meshless representations" (2025):
What they did in the 2025 paper is that they used a tetrahedral mesh ("cage") to animate meshless geometry like voxel or SDF objects, which are (by themselves) notoriously hard to deform and animate, which is one of the reasons they have been used relatively rarely so far compared to meshes.
Now the new paper instead uses a low resolution tetrahedral mesh to animate a high resolution skinned triangle mesh, which greatly speeds up ray tracing of animated triangle meshes, which is normally quite expensive.
Also a notable: the 2025 paper was also based on a paper from the previous year at the same conference, "Interval Shading: using Mesh Shaders to generate shading intervals for volume rendering" (2024): https://youtube.com/watch?v=BbMGtfMei10
5 comments
[ 1.6 ms ] story [ 18.8 ms ] threadhttps://youtu.be/h2V8YyfKCVs?t=4421
https://youtube.com/watch?v=JzWYo-t4do4
https://hal.science/hal-05095359/file/Real_time_rendering_of...
What they did in the 2025 paper is that they used a tetrahedral mesh ("cage") to animate meshless geometry like voxel or SDF objects, which are (by themselves) notoriously hard to deform and animate, which is one of the reasons they have been used relatively rarely so far compared to meshes.
Now the new paper instead uses a low resolution tetrahedral mesh to animate a high resolution skinned triangle mesh, which greatly speeds up ray tracing of animated triangle meshes, which is normally quite expensive.
Also a notable: the 2025 paper was also based on a paper from the previous year at the same conference, "Interval Shading: using Mesh Shaders to generate shading intervals for volume rendering" (2024): https://youtube.com/watch?v=BbMGtfMei10