Character Assembly prepares supported grooms for hair simulation using Geometry Nodes and Blender's XPBD solver. Physics controls apply to the character selected in Rig Instances.

Enable Hair Simulation

1. Open the Character Assembly tab and select your character in Rig Instances.
2. Enable the checkbox in the Physics panel header.
3. Play from the scene's start frame to preview the simulation.

Until you bake, hair simulation is calculated as the animation plays. Jumping directly to a later frame does not calculate the frames before it.

If the panel says No groom on this character can be simulated, the imported character has no simulation guides available. Check that the export includes a groom with simulation data and that Hair was enabled during import.

Bake the Simulation

1. Save your .blend file.
2. Set the scene's start and end frames to the animation range.
3. Set Warm-up Frames if the hair needs time to settle before the first frame.
4. Click Bake Simulation and wait for it to finish.

The bake stores this character's hair simulation on disk beside the saved file. You can then scrub the timeline freely and render the animation. Keep the bake files with the .blend when moving the project.

After changing animation, physics settings, or collision, click the trash button beside Bake Simulation (Delete Bake), then bake again.

Custom Collision

Assembly assigns an automatic collision mesh. To use your own:

1. Prepare a mesh covering the surfaces the hair should collide with. Keep it simple to reduce simulation cost, and make sure it follows the character where needed.
2. Select the character and expand Physics > Collision.
3. Choose your mesh in the object picker.
4. Adjust Margin, preview the motion, and re-bake.

The selected mesh replaces the collider assignment for this character's simulated grooms. Clearing the picker removes that assignment; it does not restore the automatic collider.

Settings