Vertex Animation Textures

Cloth, destruction and fluids cost too much to simulate in a game, so they get baked: each vertex's position, frame by frame, stored in a texture and played back in the vertex shader. Every engine and every DCC does it differently. In 2020 I wired one up by hand for a dismemberment study. In 2026 I built the tools.

• Six kinds of data in Unreal: Bone, Vertex, Soft Body, Alembic, Fluid and Sprite.
• Sources from Houdini and from Blender's OpenVAT, and from each engine itself: skeletal animation, Alembic, Geometry Collections, Niagara caches, particle systems.
• The size of a bake should be known before it is baked.
• A character baked to textures still has to hold a weapon in its hand.

In Unreal, the VAT Management Suite. An import wizard for Houdini and Blender exports, a baker that turns Unreal's own sources into textures and a static mesh, a manager that finds every VAT asset in the project, and a preview. A running mannequin, every frame sampled, comes out at about 68 KB at 512 × 17, and the tool tells you that before it bakes.

In Unity, EQ VAT Lab. Bakers for bones, vertices, Alembic streams and particle sprites from Shuriken and VFX Graph, and an importer for Houdini's VAT 3.0 exports, for Unity 2022.3 and Unity 6. Each instance plays at its own frame and speed, budget profiles warn about texture memory before a bake, and a socket tracker lets a weapon follow the hand of a character that is skinned on the GPU.

The VAT Management Suite is part of EQLabs Pro, and EQ VAT Lab is on the Unity Asset Store. The dismemberment I wired by hand in 2020 is now a few clicks in either engine.