Unreal Engine provides a dedicated SideFX Houdini Plugin to import and process VAT textures, making the setup much easier. If you’re looking for a deep dive into configuring Blueprints and materials, I highly recommend checking out the SideFX documentation and tutorials linked at the end of this post.

I use a projectile impact as the animation trigger, allowing destruction to happen dynamically when an object (like a bullet) hits the fractured surface. The Blueprint setup ensures that the VAT animation only plays when needed

Key Steps of Blueprint and Material Setup for VAT with Projectile Trigger

1. Import VAT Assets & Create Material Instance

   • Import the Full Simulation Location Texture, First Frame Texture, and Rotation Texture into Unreal Engine.

   • Create a Material Instance that reads the VAT data to animate the mesh.

2. Apply the First Frame Texture (Default State)

   • Before any interaction, the mesh displays the First Frame Texture, keeping it intact until triggered.

   • This ensures that the object looks solid before an impact occurs.

3. Set Up the Projectile Blueprint

   • In the Projectile’s Blueprint, add a collision event that detects impact with the VAT object.

   • When the projectile collides, it sends a signal to trigger the animation.

4. Enable VAT Animation in the Blueprint
   Inside the VAT object’s Blueprint, create logic to handle animation playback:

   • RT Draw This (Boolean Variable)

     • Initially set to false (object remains in its first frame).

     • When the projectile hits, set it to true, switching from the First Frame Texture to the Full Simulation Location Texture.

   • RT This Frame & RT Prev Frame

     • These values track animation progression, ensuring smooth playback.

     • When triggered, they start cycling through the VAT textures, simulating real-time destruction.

5. Trigger Animation on Impact

   • When the projectile hits, it changes RT Draw This to true, starting the destruction animation.

   • The mesh seamlessly transitions from intact to fractured, playing the pre-baked VAT animation.

Although my Houdini VAT exports didn’t show any noticeable issues, their behavior in Unreal Engine Blueprints was quite interesting.

• Pillar geometry performed the best, as the falling pieces transitioned smoothly with accurate physics and collision. The simulation respected the modular breakup, making the destruction realistic and predictable.

• Larger/wider geometries (such as walls) had more conflicts in determining which piece should fall first, leading to a messy animation. This was likely due to how VAT interprets activation zones—larger meshes require more careful control over active areas to prevent unintended overlapping.