Add a volumetric fog demo

[Calinou]

Marked as draft as I need help to get the mouselook script working again. It's based on https://github.com/godotengine/godot-demo-projects/blob/master/3d/waypoints/camera.gd, but with the 4.0 changes, I couldn't figure out how to make it work as expected.

This is an example of Godot's volumetric fog capabilities with the Vulkan renderer.

Showcased features are:

• Positive/negative density volumes that affect albedo (incoming light) and emission.
• Box/ellipsoid shapes, height falloff, and density modulation using a 3D texture.
• Temporal reprojection for greater stability and avoiding flickering.
  • The difference is demonstrated with a moving fog volume.
• Global density adjustment. With FogVolume nodes that have a positive density, it's possible to apply volumetric fog only in specific areas.

TODO

• Add custom fog shader example (some 3D noise is likely a good start).
  • Edit: Done in Improve volumetric fog demo #1014.

Preview

Video

volumetric_fog.mp4

[ScorpionInc]

I got the camera script to run on 4.0 alpha 1 with minor tweaks. Also got it to be able to go up and down as well. Available here: https://github.com/ScorpionInc/CameraLook-Test-Godot-4.0-Alpha1 hope it helps looking forward to trying out this demo. Edit: Updated code.

[ScorpionInc]

Just tested the demo the camera script seems fine to me the only change I had to do was from: transform.basis = Basis(rot, 0) to: transform.basis = Basis(Quaternion(rot)) hope this helps o/ I was tying to help with the shader but I'm still learning, I'll let you know if I get anything decent working.

[aaronfranke]

@ScorpionInc In Godot 4.0, instead of a constructing using Euler angles, you use the new explicit Basis from_euler method. https://github.com/godotengine/godot/blob/master/doc/classes/Basis.xml#L69

[aaronfranke]

Thanks!