Render to point cloud/volmetric data

[Algehov]

Hello!

Is there a way that I can render a scene/object to a point cloud or a volmetric format? With baked point color.
If I want to have a point cloud representation of an asset for example.

I know I can convert a render to a point cloud through a world position pass, but that only works from that camera angle. So Im thinking more of converting the volume of a scene or mesh to points. Similar to how you render into a vrscene.
It sounds like Atom View is doing something similar as a first step, to convert a Vray asset to a point cloud, but Im not quite sure how.

Any ideas?

[elmiguel]

What about a Deep render?

[Algehov]

That would still only help from the camera angle right? The backside of objects wont have deep data. Unless I do deep renders around an object, like you do with photogrammetry. Im trying to avoid that however.

[vlado]

For AtomView specifically, you can use the V-Ray texture baking tools to bake into a point-cloud .vrmesh file. See here for more information:
https://docs.chaosgroup.com/display/...Baking+Options

It says Ptex, but you can actually bake to a .vrmesh as well.

Best regards,
Vlado

[Algehov]

Thank you Vlado! Thats pretty much exactly what we need I think. Gonna look into this a bit more.
Is there an easy way to convert the vrmesh to an alembic with points and color? Thinking of opening it in say Nuke, Houdini, or a standalone viewer.
Or maybe Ill find the information I need if I open the vrmesh in a text editor, so its easy to convert on our own.


Cheers,
Simon

[vlado]

Not right now, but we can do a conversion tool relatively easily. For now you can open the resulting .vrmesh file in 3ds Max/Maya etc and render it out, or you can use the vrmesh_viewer tool to look at it. If you think it work for your purposes, let me know and we can do something about the conversion.

The .vrmesh files are not text files; we do ship a C++ library with V-Ray for reading and writing .vrmesh files if you are interested in developing such a tool on your own.

Best regards,
Vlado

[Algehov]

Everything seems to be working just as we where hoping for. Awesome.

A conversion tool would be great if you guys can find the time however!
Vrmesh_viewer was great for confirming that everything was working as we wanted. And its all looking good.

In the end we want to be able to view it in a standalone viewer, similar to Sketchfab, that we link together with assets.
Another use we are thinking about is perhaps doing some auto remeshing of the points, for low res geo representations of the assets. Used for quick stage dressing, that would later be swapped for the real asset, either at render time, or when needed.
All of that would require access to the points outside of the vrmesh however. Most likely alembic.

We might look into C++ library for reading vrmeshes, and writing it out ourself. Great to know that is an option.

Thanks once again

[vlado]

Ok, will make a note to look into it, but it might be a few days. In the meantime, the library that we provide is called meshes_s.lib on Windows. The associated header file is called "mesh_file.h" in the "include" folder of the V-Ray SDK (usually something like "C:\Program Files\Chaos Group\V-Ray\Maya 2018 for x64\include").

If you have any questions, ask

Best regards,
Vlado

[Algehov]

Great as always, Vlado! Thanks a ton.

A few days was way quicker than I was hoping for, and Im sure others would have use for such a convert tool aswell (not only for extracting point clouds). Let me know when you got something we can try
And great info on where to get started with the library. Will look into it.

Cheers