can it be done?

As far as I've been able to disern, there are primarily two ways to change Instances, shader strings and pscale, Is there anything else I can do? I'd love to know any other ways I can manipulate Instances… If you find that the above is true as far as you know, please reply so I know to move on…

Here's the sitch: One geo with animation cycle, Instanced N times. Can I offset its animation in such a way as to make each instance play at a different place in its cycle thus no two instances are in sink? I can offset animation cycles all day long without the geometry being Instanced but thats not what I'm trying to do here.

Thanks a bunch for any help
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I do this by adding a custom point attribute to the particle system called “offset” and then use the point SOP to add the instance attribute which takes into account this offset attribute.

Do the following:

Add attribcreate SOP
Set Group Type to Points, set Name to offset, set Class to Point, set Type to integer, set first fielnd Value to something like:

int(round(rand($PT*16.7)*7))

This will create a custom attribute and OFFSET variable with interger values ranging from 0 to 7 (the 16.7 value is arbitrary, I just found that feeding the rand function a float number is more random than giving it a int).


Now attach a point SOP and in the particles tab, Add Instance fill in something along the lines of:

/obj/Instance_animation1/instance_`(($F+$OFFSET)%8)+1`

(this is an object path, not a sop path) This will assign each particle an instance attribute with a string value that is offset by the $OFFSET variable (the one that got created automatically with attributecreate) and will range from 1 to 8.

Unfortunately, I believe you can't make the instance attribute point to a file on disk, meaning that you have to have an object node in houdini somewhere for every stage of your baked animation, unless I can be proven wrong. I think this is a standing rfe.

I've made a digital asset that generates copies of a base object automatically when you point it to a baked animation. It's clunked together for my own purposes, but if you want it, let me know and I'll update and post it.

What you're suggesting is pretty much what I allready have, I'm using 3 sets of random lookups that point to a serries of offset /objs, (obj/name_offset1_offset2_offset3)
I put up that post yesterday in hopes of gleeming some knowledge that I hadn't run into in any of the formus… You hit the nail on the head saying that “you can't make the instance attribute point to a file on disk”, thats really what I was hoping to get around. As it stands the system I'm currently using is working pretty good.

I'm still going to put it out there: Does anyone know of any other ways to manipulate instances, other than shader strings and pscale?..

Thanks again DriesD

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