Extremely slow in initialisation of cuBVH

[YZsZY]

Hello author~ Recently I've been testing cuBVH in RTX 3070, torch 2.1.0, cuda 11.8, ubuntu 20 and I found that when initializing the mesh is extremely slow and takes half an hour, however, the same mesh using raytracing initialises in just 10 seconds or so, I'd like to ask you if you've encountered this problem!

import cubvh
import raytracing
import trimesh

mesh_file = "XXX.obj"
scene_mesh = trimesh.load(mesh_file)
scene_tracer = cubvh.cuBVH(scene_mesh.vertices,scene_mesh.faces)  # raytracing.RayTracer(scene_mesh.vertices, scene_mesh.faces)

[YZsZY]

I install cuBVH in RTX 4070, torch-1.13.0-cu117, initializing the same mesh file is very fast, but in RTX 3070,torch-2.1.0-cu118 is very slow T-T

[ashawkey]

@YZsZY Hi, it sounds strange as the raytracing package almost uses the same code as cubvh. Have you tried running several times and average the time? The first run's time maybe inaccurate.

[YZsZY]

@ashawkey Hi, thanks for the reply~ I tested it on two different sizes of mesh, the speed is similar on a very simple mesh, but on a very complex mesh (scannet++) the difference is huge, I encountered this on 3060, 3070, and A100 with cuda11.8+torch2.1.0，it's really strange T-T.

With a complex mesh:

With a simple mesh:

[HarukiZhang]

Hello, guys, I have also encountered this slow initialization.

In my case,

• ubuntu 20.04,
• RTX 4090 D, driver 550.67
• CUDA 11.8,
• pytorch 2.0.0,
• cubvh 0.1.0,
• libstdc++.so.6.0.29 is used in my environment;

When I tried to initialize cubvh with a scene that contains 3773056 vertices and 7155510 faces, it takes 323 seconds for initialization and 0.001568 sec for .ray_tracing() for 2^20 rays;

I wonder whether this initiliazation time comsumption is normal?

[ashawkey]

@HarukiZhang I guess at this level of vertices and triangles, it's normal.