graphdeco-inria / gaussian-splatting

Original reference implementation of "3D Gaussian Splatting for Real-Time Radiance Field Rendering"
https://repo-sam.inria.fr/fungraph/3d-gaussian-splatting/
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How can I know which gaussians contribute to a certain rendering? #726

Open wen-yuan-zhang opened 7 months ago

wen-yuan-zhang commented 7 months ago

I have already known that I can use radii>0 to filter the gaussians which project onto a certain view. However, I want to know which gaussians contribute to a certain rendering? Or, which gaussians can receive grads after backpropagating during once rendering? Are there any interfaces about this? A similar issue was #159, but I am not familiar with cuda and I cannot well understand it...

robofar commented 6 months ago

Hey. Can you tell me what excatly radii>0 represent for specific viewpoint. If I have map of 3D Gaussians, for specific viewpoint, what would radii value of 0 mean? With radii > 0 which information can we infer? Can we tell about how many Gaussians are in view frustum for that viewpoint or something else? I am confused about this mask.

robofar commented 5 months ago

@zParquet any update?

Xzzit commented 5 months ago

I believe the radii parameter represents the radiance of a specific Gaussian distribution. If radii > 0, it indicates that this Gaussian distribution is "visible" from a particular viewpoint. Otherwise, it is considered invisible and can be ignored during rendering.

wen-yuan-zhang commented 5 months ago

@robofar The explanation from @Xzzit is right. radii>0 means that this Gaussian is inside the viewpoint, otherwise is outside the viewpoint (the corresponding rgb image).

robofar commented 5 months ago

@zParquet and @Xzzit thank you