Add a 3D antialiasing demo

[Calinou]

This demo showcases the various 3D antialiasing techniques supported by Godot. Many potentially problematic cases for TAA such as godotengine/godot#69493 are also included, so this will be used as a testing project for the purpose of improving Godot's TAA implementation.

Preview

TODO (in future PRs)

• Add animated skinned mesh (skeleton) test case.
• Add animated skinned mesh (blend shape) test case.
• Add SoftBody test case.
• Add complex model test case to check for specular aliasing.

[clayjohn]

We should keep our eyes open for a cc0 licenced model with a more complex profile. Something thin like a powerline is important to show how well different AA techniques preserve shape.

[Calinou]

Rebased with TAA support. This should now be ready to be merged.

[clayjohn]

Before merging we really need to use a better model. Cubes are not sufficient to clearly show the differences between AA methods. Consider using something like this https://polyhaven.com/a/dutch_ship_medium which has a good amount of thin geometry.

[Calinou]

Before merging we really need to use a better model. Cubes are not sufficient to clearly show the differences between AA methods. Consider using something like this polyhaven.com/a/dutch_ship_medium which has a good amount of thin geometry.

Done, I added this model in the test scene (with 1K textures to keep file sizes low). Textures are blurry when up close in 2560×1440, but it still demonstrates the effect of antialiasing well.

[clayjohn]

Looks great to me! It was lots of fun to step through and it does a nice job of covering a wide range of edge cases.

I will leave it up to someone with more knowledge about the demos to approve with respect to organization/code quality.

[aaronfranke]

Nice! Thank you, this demo is super polished.

I pushed some updates, including some minor changes to the camera script and default camera angle, an updated screenshot, renaming the scene and script, moving textures to a subfolder, and optimizing PNG files using oxipng.