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facebookresearch / DensePose

A real-time approach for mapping all human pixels of 2D RGB images to a 3D surface-based model of the body
http://densepose.org
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How do you make 'UV_Processed.mat' ? #246

Open jbjeong opened 5 years ago

jbjeong commented 5 years ago

Hello, thanks for great work!

I wonder how do I make 'UV_Processed.mat'. I want to make a figure which visualize uv coordinate on other pose of SMPL template. To be specific, the SMPL template with the pose of human in the input image is needed. Now, I have deformed SMPL template, but uv coordinates from Densepose is fitted to T-pose template. And I think that 'UV_Processed.mat' file represent the mapping of uv coordinates to T-pose mesh(SMPL template). So I need to make a 'UV_proceesed.mat' for other pose mesh template. What can I do for it?

Thanks!

polygonfuture commented 5 years ago

@jbjeong In 3D animation, UV maps are independent of how a model is posed. Usually each verticies has a corresponding U and V value, so no matter where the vertices moves, the UV is mapped to that vertices independent from how that vertices is shifted.

That being said, I have no idea how they are doing it with this model. It often feels like it is done completely irrelevent of common established 3D practices.

Knowing how they generate that .mat would still be very useful. I wish the team would talk more about this (and how they get their warped texture image example from the SMPL layouts). @vkhalidov

jbjeong commented 5 years ago

@polygonfuture Thanks for your reply! I understand the independence between UV map and pose.

Do you understand how the authors obtain the UV fields provided in the SMPL model (I quote the some part of paper)? I also wonder how do they make UV map of each image pixel.

polygonfuture commented 5 years ago

@jbjeong The UV fields of the model come from the actual UV fields of the model. Every 3D model has a set of UV's associated with their verticies. If you use a 3D program like Maya, Cinema4D or UV layout programs you can specifically access the UVs and view them for any 3D model.

So for the SMPL model, when it was created the researchers / creation team created a set of UVs and laid them out so that texture maps and other image based information could be mapped to the surface of the 3D model.

I think the real question is how did they convert the original SMPL model UV's to their modified ATLAS layout. Its possible it they literally re-mapped the 3D model in a 3D program and then exported the UV fields (and their associated verticies) as that processed_uv.mat file.