Vertex Colors

Vertex colors are the cheapest per-pixel mask you can ship: data painted in your DCC tool, stored on the mesh, and read for free during the vertex stage. Genesis exposes them as tints, layer masks, vertex-animation amplitude, and dissolve gradients.

When to use it

Layer masks — paint moss, dirt, or snow weights in Blender or Polybrush.
Wind amplitude — store sway strength per vertex on foliage.
Tint variation — randomize prop colors without instancing.
Dissolve gradients — control the dissolve direction from per-vertex data.

Difference from mask textures

Texture masks need clean UVs and an extra sample per layer. Vertex colors are free (already on the mesh) but limited to vertex resolution. Use vertex colors for low-frequency masking and textures for high-frequency.

How it works

Genesis reads the vertex color in the vertex stage, optionally selects a channel via _VertexColorChannel, and forwards it to the fragment for masking or to the vertex-animation evaluator for amplitude. No texture sample is required.

Properties

Inspector label	Shader property	Type	Default	Description
Use Vertex Color	_UseVertexColor	Toggle	Off	Master toggle.
Channel	_VertexColorChannel	Enum	RGB	RGB tint, R/G/B/A mask, or RGBA composite.
Mode	_VertexColorMode	Enum	Tint	Tint, LayerMask, WindAmplitude, or DissolveDriver.
Strength	_VertexColorStrength	Float (0–1)	1.0	Blend amount against the unaffected value.
Bias	_VertexColorBias	Float (-1–1)	0.0	Constant added before strength.

Usage

Paint vertex colors in Blender (a vertex color layer), Maya (a color set), or Polybrush.
Confirm the mesh has them: select the asset and look for “Has Vertex Colors” in the Mesh Info.
In Genesis, enable Use Vertex Color and pick the channel and mode.
For wind, set Mode to WindAmplitude and paint the sway strength directly on the mesh.


material.SetFloat("_UseVertexColor", 1f);
material.SetFloat("_VertexColorChannel", 0); // R
material.SetFloat("_VertexColorMode", 2);    // WindAmplitude

Tips & gotchas

Unity primitives have no vertex colors; only imported or painted meshes do.
Vertex color interpolates across the triangle, so masks soften by triangle size. Subdivide for sharper masks.
Vertex colors are not gamma-corrected. In a linear project, the values you painted are the values you get.
Static batching strips per-renderer colors — use GPU instancing for unique tints per instance.

Layer Textures — the primary consumer of vertex masks.
Vertex Animation — vertex R drives wind amplitude.
Dissolve — vertex color as a dissolve gradient.
Mesh Utility — paint and verify vertex colors in-editor.