feat(extended translucency): "scattering volume" material

[ArcEarth]

trafficstars

Adding a new material model to the feature: ScatteringVolume This material is modeled after a ball of smoke, which scattering light exponentially through it.

It is unique because its the first material model that "fade out" the mesh, instead of strengthening its edges.

This material was originally designed for Ghost, or SetActorAlpha. But it does not work out of the box yet:

1. The EffectShader of a regular ghost is way too strong, making it hard to see difference in the mesh's rendering.
2. We disabled this effect in SKIN shader to avoid rendering issue with makeup and face details.

Summary by CodeRabbit

Summary by CodeRabbit

• New Features

  • Added a new "Scattering Volume" material mode for extended translucency effects.
  • Included "Scattering Volume" option in the material model selection with updated descriptive tooltips.

• Improvements

  • Improved alpha handling for anisotropic materials with view-dependent alpha adjustments.
  • Refined transparency behavior for scattering volume materials with view-dependent fading.

• Bug Fixes

  • Ensured alpha values are properly clamped for improved visual consistency.