Pyro_event_manager

Houdini Digital Asset (pyro_event_manager) that puts pyro events on drones: on which frame each drone fires which of its pyro channels, how long the pyro burns and how long the flame is. A point attribute used as a mask can spread the ignition over time, so the drones fire one after another instead of all at once.

The events are point attributes (channel, frame, burn duration and flame length) and travel with the animation in its Alembic file. Full_show_preview reads them from it and writes them into the preview file, and the show preview plays them as flames. Each pyro channel of a drone fires once; a second event on the same channel stops the upload.

The second output shows the flame icons in the viewport while the pyro burns.

HDA: houdinitools/hda/pyro_event_manager.hda

Parameters

Parameter	Type	Default	Description
Group `group2`	String	—	Points (drones) that get the pyro event. Empty gives it to all points.
Mask attribute `mask_attribute`	String	—	Point attribute from 0 to 1 that spreads the ignition over Mask duration: drones with 1 fire on Start frame, drones with 0 at its end. Empty fires all drones on Start frame.
Start frame `framenum`	Integer	50	Frame on which the event fires. With a mask, the first drones fire on it.
Mask duration (frames) `duration`	Integer	100	Frames over which the mask spreads the ignition. 0 fires all drones on Start frame.
`normalize_mask_value`	Toggle	Off	Stretch the mask values to the full 0–1 range over the drones first, so the ignition fills the whole Mask duration.
`debug`	Toggle	Off	Switch the flame icon in the viewport to its debug form.
Event channel `event`	Integer	1	Number of the drone's pyro channel this event fires. Each channel fires once: two events on the same channel of one drone stop the show preview upload.
Burn duration (sec) `burn_duration`	Integer	15	How long the pyro burns, in seconds. Written with the event and used to show the flame in the viewport and in the preview.
Flame Length (m) `flame_length`	Float	5	Length of the flame in meters. Written with the event, it sets the flame in the show preview, and it sizes the flame icon in the viewport.