Set Instance Geometry

 
 
 

This compound uses objects instead of particles for the geometry in a particle simulation. You can use any 3D geometric object or even other point clouds in place of particles to create many different effects. If the instanced objects are animated, you can create crowds or flocking scenes, such as with flying birds or butterflies.

Plug this compound's Execute on Emit output into an Execute on Emit port of the Emit compound.

For more information on using instances, see ICE Particle Instances.

TipThis compound uses the ShapeInstanceTime attribute which may cause issues when rendering — see Rendering Particle Instances for information and workarounds.

Tasks: Particles/Geometry Instancing

Output Ports: Execute_On_Emit

Geometry Instancing

Reference

The object or group of objects whose geometry you want to use instead of particles. You can use a single object, a hierarchy of objects, or a group of objects. Each object in a group is assigned randomly onto a particle and stays with that particle for its lifetime. This is because the instance is based on the unique ID of the particle.

Hierarchy Mode

Specifies whether to instance just an object or a hierarchy:

  • Select Object Only if the instanced geometry is a single object or a group.

  • Select Object+Children if the instanced geometry is a parent object in a hierarchy.

Group Object Index

When connecting to a group, this picks a group member according to its index value.

The index is the order in which the objects were created, as you can check in an explorer using the View General Sort None (Creation) filter.

You can change this order as described in Sorting and Reordering Elements in the Explorer.

You can also plug any type of Randomize node into this port to randomly select the objects in the group - see Using Groups of Master Objects for more information.

Out-of-range Group Index

When connecting to a group of instanced objects, this specifies how to treat group index values larger than the group size.

  • Clamp: the objects with index values outside the group object index are not considered.

  • Wraparound: the objects are automatically included.

RBD Type

If you're using the Simulate Bullet Rigid Bodies node in this ICE tree, you can select the type of collision geometry to use for the particle's instanced shape:

  • BBox creates a bounding box around the shape of the instanced geometry.
  • Convex Hull (Bullet RBDs Only) creates a convex hull approximation around the shape of the instanced geometry.

See Collision Geometry for Rigid Body Particles and Obstacles for more information.

Instance Animation

Select Initial Shape Instance Frame Value

The frame of the instance's animation you want to use as the starting frame for each particle:

  • Use Input Frame Value uses the value you enter below.

  • Use Current Frame uses whatever frame you are at.

  • Do Not Change Instance Animation Time uses the animation exactly as it is.

Input Frame Value

The frame number of the instance shape animation to use for its initial frame.