Create collision objects for hair using a Collision modifier

You can add a Collision modifier to a description so that you can assign polygon meshes as collision objects. Collision objects act as deformers that resolve intersections between splines and geometry. They can also be used to shape hair around objects such as hats.

Add a collision object

1. Add a Collision modifier. See Work with XGen interactive grooming modifiers.
2. Ctrl + select one or more polygon meshes to act as colliders along with the Collision modifier in the Interactive Groom Editor.
3. In the Collision modifier attribute group, under Collision Object, click Add Selected Objects.

   The collision objects are listed under Object Name.

Remove a collision object

1. Do one of the following:
   • In the Collision modifier attribute group, under Object Name, select the collision object you want to remove.
   • In the scene, Ctrl + select one or more of the polygon meshes you want to remove along with the Collision modifier in the Interactive Groom Editor.

     Use this selection method if you have a number of collision objects in the list, or if you do not know the names of the collision objects you want to remove.

2. Click Remove Selected Objects.

Control interaction with collision objects

• Use the Enable option beside each collision object to toggle whether the object acts as a collider or not.
• Turn on Flip Normal to push hairs in the direction that is opposite to face normal of the bound mesh.
• Set the distance between the collider mesh surface and the hairs by adjusting Collision Distance.
• Turn on Preserve Deformation so that hairs keep their deformities after colliding.
• Adjust Smooth Factor to remove kinked or jagged hair that result from the collisions.

Related topics

• XGen interactive grooming Collide modifier attributes
• XGen interactive grooming modifiers