mouse callbacks, picking and 3D pos of projected mouse click on mesh

[stigersh]

First of all thank you @nmwsharp so much for this super beautiful visualization library cpp+python! I wanted to ask how a few things which I fail to find the documentation for and I think might be implemented already -

• How do I attach a callback to a mouse event?
• How do I get the projection of my click on the mesh (3D coordinates)?
• How do I get the picking info - like the face index? closest vertex?

I'm currently trying to assign vector constraints on specific faces through UI and these will be very helpful:)

Thank you so much again!