Create Tearable Surface constraints

You can create a Tearable Surface constraint to make an nCloth object rip or shatter when it collides with passive objects or other nCloth objects. For example, you can use a Tearable Surface constraint to make a piece of nCloth silk tear when it catches on a pointy passive object.

1. Select the nCloth object you want to rip, tear, or shatter.
2. (Optional) If you want your nCloth to shatter rather than tear, set its Bend Resistance to a value greater than 0.2. See nCloth Dynamic Properties.
3. Select nConstraint > Tearable Surface > .

   The Create Tearable Surface Constraint Options Box window appears.

4. (Optional) Turn on Use Sets to add the nCloth object to a dynamic constraint selection set.
5. Click Create Constraint or Apply.

   The current nCloth is made tearable or shatterable by separating all of its faces, generating new edges and vertices, merging the nCloth’s vertices, softening the nCloth’s edges, and constraining the nCloth’s points (tear) or edges (shatter) together using the Weld constraint method. As a result, the topology of your nCloth’s output mesh will no longer match that of its input mesh.

   The nCloth object you selected is now also connected to a dynamicConstraint node.

   The preset properties on the dynamicConstraint node determine the constraint’s type (in this case, a Tearable Surface constraint) and how it behaves. For example, you can create a Tearable Surface constraint with the following attribute settings:

   • Weld as the Constraint Method.
   • Object to Object as the Constraint Relation.
   • All to All as the Component Relation
   • Within Max Distance as the Connection Method.
   • At Start as the Connection Update.

   See dynamicConstraintShape.

6. To adjust how easily your nCloth tears or shatters, increase or decrease the Glue Strength of the Tearable Surface constraint. See Dynamic Contraint attributes.
7. (Optional) You can also direct where the tearing or shattering is to occur on your nCloth by painting a Glue Strength map.
   Note:

   • If you want to add additional constraints to your tearable or shatterable nCloth, add them to its input mesh (nMeshShape).
   • If you want to paint any texture maps for your tearable or shatterable nCloth, paint them on its input mesh. Also, since making an nCloth tearable or shatterable changes its output mesh’s topology, do not use vertex maps with tearable or shatterable nCloth objects.