Trail surface node

Creates trails behind points.

The Trail op takes an input op and makes a trail of each point of the input op over the past several frames, and connects the trails in different ways. It will generate trails of any input geometry, whether it is a cube translating, a deforming surface, or particles. This is useful for multi-frame ghosting effects and temporal modeling.

When using a Particle SOP or Spring SOP as input, it is important to keep the trail increment to integer values. Otherwise, the trail will not work well.

Examples

Velocity Computation

The particles thrown off the end-most points receive a higher velocity than those close to the root of the L-system (enable Points display in Viewport Display):

Temporal Modeling

Temporal modeling with the Trail op: the corners of a translated and rotated cube are used as a source for the Trail op with a Trail Length of 50 frames connected by Columns.

Parameters

Result Type	How to construct the trail geometry.
Trail Length	Number of frames in trail.
Trail Increment	Number of frames to skip in trail.
Cache Size	Number of frames to cache in RAM.
Reset Cache	Resets the cache memory buffer.
Evaluate Within Frame Range	Clamp evaluation between $FSTART and $FEND, otherwise may evaluate before start frame.
Connectivity	How to create the output mesh.
Close Rows	Closes the rows in the output mesh.
Velocity Scale	Non-uniform scaling of velocity vectors.

Usages in other examples

Example name	Example for
MountainSplash	Attrib Transfer surface node	Load \| Launch
ParticleCopyScale	Copy surface node	Load \| Launch