DeepFrostIceShader

The backface refracts the background captured by its own dedicated GrabPass according to Refraction Strength / Chromatic Aberration, then layers the inner wall on top — the result is then seen warped again through the front face's refraction and chromatic aberration (light bends twice: once entering, once exiting). The inner wall's color follows Deep Color for bare ice and Frost Color where frost has formed.

To use this in a world that supports VRC Light Volumes, the world itself needs REDSIM/VRCLightVolumes installed. A reference copy of LightVolumes.cginc is bundled so the shader doesn't throw material errors in the avatar-side project. The bundled file is MIT-licensed code from REDSIM/VRCLightVolumes.

Raising Frost Coverage adds noise-based frost even without a mask texture. When using Frost Mask (R), it guarantees frost on the white areas while Frost Coverage layers on additional edges and grain.
Animating Freeze Amount spreads frost outward from the Fresnel edge and the densest crystal-noise areas until the whole surface eventually freezes over. The frost density on frozen areas follows Frost Intensity. Combine it with Dissolve Amount for a "freeze, then shatter" effect.

Melt Amount erodes frost uniformly, whether it came from a texture mask, Frost Coverage, Freeze Amount, or Top Snow Amount. Unlike Freeze Amount, it melts the Fresnel edge and thin crystal-noise areas first, leaving the densest crystal areas intact the longest. Raising Melt Water Film makes low-frequency noise flow in two directions across exposed surfaces — scaled by the melt amount — appearing as a thin water film with boosted Smoothness, normal detail, and refraction. At 0, the extra calculation is skipped entirely and the previous look is kept.

Looks at the upward (Y) component of the world-space normal and adds a mask — deeper frost the more a surface faces upward — into the existing frost value. It layers cleanly with Frost Coverage and Freeze Amount since all three feed the same frost value, so matte shading and specular falloff stay consistent automatically.

Sparkle flickers as the camera or light moves, and even when both are still, per-glint phase drift from Sparkle Twinkle Speed keeps the glints twinkling gently. Combine it with Frost Coverage or Freeze Amount for a look of glinting snow or frost grains. Raising Sparkle Rainbow gives it a diamond-dust-like prismatic shimmer.

Animating Dissolve Amount lets crystalline frost freeze over the surface first, then break apart like ice chips at a boundary formed by an ice fracture cross-section — whose per-facet shading changes with the lighting direction — and a thin blue-white core. The wide freeze front turns matte and cloudy using the same crystal noise as regular frost, the cross-section blocks the background with irregular triangular cells sized by Dissolve Ice Grain Scale, and the glow is kept confined to the thin core at the boundary. This isn't a recreation of lilToon's Dissolve — it's a purpose-built look for this shader's take on ice.
If the very end disappears all at once, try pushing Dissolve Ice Grain Blend closer to 1, or lowering Dissolve Broken Edge slightly, for a smoother finish.