Why VAT?

Vertex animation textures store per-vertex positions for every frame in an image. A simple vertex shader reads them back, so you can render thousands of animated instances (crowds, foliage, destruction, cloth, FX) without skeletal skinning cost. Most VAT tools live in Houdini. This one runs entirely inside Maya, in pure Python.

Features

Anything that moves

skinCluster, blend shapes, lattices, nonlinear deformers. If it deforms the mesh, it bakes.

Zero dependencies

Pure Python + Maya API. Writes PNGs without PIL/numpy. Maya 2022+ with PySide2/PySide6.

Object or World space

Object space keeps runtime movement and rotation working. World space suits static props.

Auto VAT UVs

Generates a dedicated UV set that maps each vertex to its texture column.

Skip first frame

Use a T-pose or bind pose as the reference mesh without baking it into the animation.

One-click export

Position PNG, optional normal PNG, bounds JSON and a skin-free proxy FBX.

Install & Run

Download the latest release and extract it.
Rename the folder to maya_vat and copy it to Documents/maya/<version>/scripts/.
In Maya's Script Editor (Python):

import maya_vat
maya_vat.show()

Maya VAT Encoder user interface inside Autodesk Maya

Output

mesh_vat/
  mesh_vat.png      # position deltas (width = vertices, height = frames)
  mesh_vnrm.png     # normals (optional)
  mesh_remap.json   # bounds min/max for decoding
  mesh.fbx          # proxy mesh, first frame, VAT_UV set

Each pixel stores (ΔX, ΔY, ΔZ) relative to the proxy mesh, normalized to 0–255 using the min/max in the JSON. To decode in a vertex shader:

// uv  = VAT_UV (u = vertex column), v offset by current frame
// rgb = texture sample (0..1), point filtering, no sRGB, no mips
float3 delta = lerp(boundsMin, boundsMax, rgb);
position    = proxyPosition + delta;

Engine support

Engine	How
Unreal Engine	Material World Position Offset reading the VAT texture (point sampling, no compression/sRGB)
Unity	Shader Graph / HLSL vertex stage, sample with `tex2Dlod`
PlayCanvas / three.js / WebGL	Custom vertex shader chunk. Normal X is pre-flipped for PlayCanvas.

FAQ

Do I need Houdini?

No. Everything is baked inside Maya.

Object space or world space?

Use Object space for characters that move or rotate at runtime, including root-motion clips. World space is only for objects with a fixed transform.

Is it free for commercial use?

Yes, it's MIT licensed.