Big Runtime Error with some particular BlendParams about pytorch3d HOT 5 CLOSED

@michele-arrival this is not because of the blend params but the rasterization settings. Currently your values are:

raster_settings = RasterizationSettings(
    image_size=frame_size,
    blur_radius=np.log(1.0 / 1e-4 - 1.0) * blend_params.sigma,
    faces_per_pixel=2,
    bin_size=1
)

There are two implementations of rasterization in pytorch3d and the approach that is used is determined by the value of the bin_size setting.

The first naive approach (when bin_size = 0) loops through all the faces in the mesh for each pixel. The second approach (when bin_size > 0) involves two steps the first of which is a coarse step where the image is split into a rough grid (or bins) and each face in the mesh is assigned to a grid cell (or bin). The second step loops through each pixel and only looks at the faces in the bin in which the pixel lies. Refer to the docs on the renderer for more details on this 'coarse-to-fine' approach: https://pytorch3d.org/docs/renderer. Also refer to the PyTorch3D API docs for the rasterizer here

For coarse-to-fine rasterization the bin_size setting determines the number of bins and in this case you have set it to 1. There is an upper bound on the number of faces which can be allocated to each bin and as the error mentions Got 256; that's too many! (for reference with, the error is from RasterizeMeshesCoarseCuda to help you debug such issues in future).

If you want to enable the coarse-to-fine rasterization you can just leave the bin_size empty and it will be set based on heuristics. If you want to use the naive rasterization approach you can set bin_size = 0.

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Yes sorry of course I meant RasterizationSettings.

Thanks for the explanation, I understand now.
I guess a clearer error message wouldn't be too bad though. For one thing it looks like a low level exception, not a user error, even thought it is. Also It's not immediately clear what *that* in that's too many is.

As a side note, when the image is big (> 1024) leaving bin_size out of the settings means another kind of exception incompatible function arguments later on.
see here where bin_size remains None:

Cheers!

from pytorch3d.

@michele-arrival, yes we could definitely make the error message clearer. Thanks for pointing out the error for when image size is > 1024. We assumed that most use cases involving batched rendering of meshes would require image sizes < 1024, but we can fix this so that rendering is enabled with any image size. Feel free to submit a PR if you would like to try and fix this yourself!

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#90

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@michele-arrival your PR has been merged so I am closing this issue.

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