[Feature] Add associated volume to PPMs

[csparker247]

What problem is your feature request solving?

PPMs are often generated from surfaces which have associated volume ID's (i.e. from VC Segmentations as opposed to some random input mesh). However, this information is lost in the PPM encoding. As a consequence, the vc_*_from_ppm utilities generally require the --volume flag in order to function correctly.

What is your feature request?

Add associated volume metadata into the PPM header. The setter and getter will be easy to add to the PerPixelMap class. Changing the PointSetIO interface to support extra metadata fields in the header is more complicated, but not impossible (maybe something with std::optional or std::map or whatever). Updating usages will also require some attention to detail. But generally fairly easy.

What alternative solutions have you considered?

We could make the --volume flag required rather than defaulting to the first one. But that makes single volume .volpkg more annoying to work with and ultimately just makes the user work harder.

Is there anything else we should know that wasn't included already?

No response

Are you proposing to work on this feature yourself?

• I am willing to submit a pull request for this feature

Code of Conduct

• I agree to follow this project's Code of Conduct