The Constrain Strand Length compound makes the strands follow particles like trails. If the particles leave the emitter, the strands follow behind like strings that always keep the same length. This compound is useful for creating hair, if you're creating with particle strands that have no emission Speed. The strands don't follow the particle's path exactly as they do with Align Strand with Particle Trajectory compound.
Create strands with the Create Strands compound, then plug this compound's Execute output into a port on the ICETree node.
For more information on strand compounds, see ICE Particle Strands.
Tasks: Particles/Strands
Output Ports: Execute
Autodesk Softimage v.7.5