Query : 4 channels in nerf output

[aradhyamathur]

Hi, I have a query pertaining to the voxnerf implementation, the features generated 4 channels, whereas the density feature is computed separately, does the last channel correspond to alpha ?

[aradhyamathur]

I wanted to test with vanilla nerf implementation like stable diffusion, the outputs there are 3 channel, so wanted to know what change could be made for the same.

[w-hc]

The four channels are for the latent features of Stable Diffusion. It’s not RGBa. The density is controlled by another small 1-channel voxel.

[aradhyamathur]

Oh I see, so it's essentially predicting the latents which are then denoised by the SD network to produce the RGB while density is predicted from the other module. Is that correct ?

[w-hc]

That’s right.

[aradhyamathur]

Thanks for the clarification.