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InstanceTrailer
Turns one moving image into a trail of its recent frames: a cache laid out in a row or column with exponent-shaped spacing, plus the offsets as a CHOP for instancing.
◧ Visual ◆ Patreon:Base
This tool unlocks with Patreon. It installs through the same picker as everything else and unlocks with the Patreon Base tier or higher, connected from inside TouchDesigner. Everything else in the toolkit stays free and MIT, and the membership is what keeps that work moving.
What it is
InstanceTrailer caches the incoming frames and lays the most recent ones out side by side, oldest at one end and newest at the other. Depth says how many, Direction and Expval shape how the samples are spread through the cache, so the trail can bunch up near the present or fan out into the past. The layout is a texture and the sample positions ride out as a CHOP, which is what an instanced geometry needs to draw the trail in 3D.
It is a member of the FNS operator family: pick it from the FNS tab of the OP Create dialog and it lands as one node.
Inputs and outputs
- in1 (TOP): the frames to trail. The cache records only while something is wired in.
- out1 (TOP): the laid out trail.
- out2 (CHOP): the trail as pixel data (one sample per pixel of a second, identical layout, r g b a channels), for instancing or CHOP-side use; the first block is the newest copy and the last block the oldest, matching out1 top to bottom.
Parameters
Custom
| Control | Type / default | What it does |
|---|---|---|
DepthDepth |
number10 | Number of delayed copies (instances) drawn in the trail, the live frame included. |
Max Cache SizeMaxcachesize |
number300 | Frames the cache holds. The trail cannot reach further back than this; larger values use more GPU memory. |
Cache SizeCachesize |
number300 | How many frames back the oldest copy reaches. Clamped to Max Cache Size: the cache holds nothing further back, so a larger value would read empty slots. |
DirectionDirection |
number1 | Direction and strength of the time offset, -1 to 1. Positive values delay the copies into the past, negative values reverse the order; at +-1 the oldest copy reaches Cache Size frames back. |
Exponent ValueExpval |
number1 | Exponent that spaces the delays: 1 is even spacing, higher values bunch the copies near the live frame. 0 puts every copy on the same frame. |
AlignAlign |
menuTop to Bottom | How the copies are arranged in the output layout. |
Recreate All OperatorsRecreateall |
button | Rebuild every replicated copy, for example after changing Depth by a large amount. |