Injecting single point to Feedback loop - is there a better way?

POPs
1

I need to add a single point, on cue, to a Feedback POP loop.
I made a working version, by merging an extra point for the duration of one frame.

Two questions:

A) Is there a better way? As my approach feels a bit hacky/inefficient using an Execute DAT to control a Switch POP on every frame end. (see attached example A)

B) Not sure if this is a bug, but merging an extra point only works if there was already at least one existing point - why?
(See approach B in attached example). I would like to start from zero points, and then add the first point on cue.

inject-point-in-feedbackloop.toe (7.8 KB)

2

Hello @nettoyeur

Do you necessarily need to add points to a Feedback POP loop, or do you just need to add one point at a time over time on cue? You can use a Script POP and add points to a GeometryStagingData over time.

inject-point-in-feedbackloop.toe (9.3 KB)

Currently, the Feedback POP stays in an initializing state while no geometry is fed in. In your example, this results in the output points never being re-injected into a feedback loop. We’ll evaluate whether we should change this behavior.

I noticed that your first example doesn’t run as expected in 2025.33230. Changing the timing in the Python script fixed it. I would have to take a closer look at what could have changed to pinpoint the difference.

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3

Thanks for taking a look @Guillaume.L !

Yep I need to add a single point to a Feedback loop (multiple times)- it’s for a particle system where I need to be able to control single spawns on cue, and particles also have eternal life until I delete selected ones. (This is also why I did not use the Particle POP - could not find a way to give particles eternal life)

thanks for explaining Feedback POP behavior where it does not start until geo is available at its input.

And true my example does not work in 33230 I noticed today! - it worked fine in previous official 33070. But it already felt a bit hacky - your version guarantees it stays up a whole frame, so thanks!

4

A workaround for the Particle POP to set an eternal life span is to set a ridiculously long life expectancy (for example, 2e20 seconds). You can then remove particles by using the PartDeath attribute and spawn one particle at a time on cue with the Input Birth Attribute.

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