Add an option to control backface culling

[wbhu]

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Context F3D is used to render different kind of geometries, most of them contain oriented faces with a concept of backfaces and frontfaces. F3D currently always show the backface but it would be useful to control that behavior.

Suggested Solution

• Add a CLI and libf3d option to control the behavior
• Use the option in vtkF3DRenderer to set the backface flag on the actors
• VTK API to use: https://vtk.org/doc/nightly/html/classvtkProperty.html#a19e98e81aba936017e8b9eeb26658d75

[mwestphal]

I think that would be pretty trivial to add, wdyt @Meakk ?

[Meakk]

Yes, it's just a flag on the actors

[Meakk]

Here's a file I create for testing: backface.zip

And the visualization in ParaView:

1. Front/Back display:

2. With backface culling:

3. In f3d:

[snoyer]

From a related discussion on Discord we've also got an .obj file with cubes from @theuser021: backface-cubes.zip

MeshLab rendering options for reference:

• single (back facing dark)
• double (back facing same color as front facing)
• cull (back facing not displayed)
• fancy (two different colors)

[mwestphal]

Improved the issue.

[Raghav-B]

Is anyone working on this? I would love to be able to help out + its a feature I really want to have!

[mwestphal]

Well go for it! Are you on discord already?

https://discord.f3d.app

[Raghav-B]

Just joined! Thanks!

[mwestphal]

any news on this one @Raghav-B ?

[Raghav-B]

@mwestphal I'm really sorry, I completely missed your messages on Discord. I know this a really simple feature that can be added in a couple of hours but I really haven't had the bandwidth these past 2 months due to some personal issues. I would have really liked to help out with this but it would be better if you could assign this to someone else if you need this done timely.

[mwestphal]

No worries:)

[KeflerExe]

Im working on it :)