SDF 2D / 3D Rendering improvements - call for input / help

[vade]

We ported some of Lygias SDF functions into single channel and two channel effects, but theres a lot more we can add, let a lone the 3D Shapes via ray marching)

This is a nice self contained project for folks that want to contribute without needing to learn a ton of Fabrics code base of Swift

Some things that would be nice to have

2D SDFs

• Additional shapes as generators in Fabric
• Additional operators exposed from Lygia as two channel inputs
• Update the shared include to support analytical anti-aliasing techniques

the 2D SDFs would basically be copying a template, and changing some import code and functions and making sure stuff renders correctly!

3D SDFs

• Propose / Expose a way to conform the 3D SDF a camera's matrix, so an SDF can be rendered similar to the scene
• Create a standard include which all 3D SDFs will adhere to (similar to the 2d include)
• Expose shapes
• Expose operators
• Expose blending

the 3D SDFs would be a new tranche of work, and would require a bit more knowledge but would be a great project for volks feeling adventurous !