I'm trying (without success) to use the Particle CHOP,
This chop produces translate and rotate channels to move Objects according to the positions of particles in a pop Network. Channels are generated for all particles with an instance attribute and which have the override state turned on.
For a quick test, I created a pop network with a single particle birthed at frame 1. This particle moves around under the influence of an orbit POP. To the end of this short network I added an attribute POP to create the ‘instance’ attribute (gave it value 1). I have no idea what “have the override state turned on” means. As I'm not seeing any channels created by the Particle CHOP, I'm obviously doing something wrong. Could someone please point out my error?
(As an aside, how can you search the forums for occurrences of the phrase “particle chop”? If I enter this quoted text, I seem to get posts that have any occurrence of “particle” and “chop”, not necessarily adjacent. It would also be nice to search only post titles.)
The “override state turned on” part refers to a flag indicating that a particular particle's transform should be used to override that of the instance geometry. This flag dates from the old RBD that used to be part of POPs.
The flag still exists in 8.1, and can be controlled via the state POP. The relevant parameters are invisible, but can still be set using the opparm command. In particular, you'll be interested in the “dooverride” and “override” parameters. The helpcard for the state POP still mentions these parameters.
These parameters, and the particle CHOP's reliance on this flag, have been removed from the next version of Houdini.
Coming back to this, I'm still struggling to get the Particle CHOP working. I've created the simplest of hip files to demonstrate. Could I trouble someone in the know to download my hip and spot the error? As always, any help is much appreciated.
Yeah I guess the current way to do it would be copy stamping or using attributes of particles for various things. Also could be done with the geometry CHOP set to animated, with Channel nodes or chopi, chopf expressions.
Would be nice to see some CHOPs improvement with H9 though
