Russ, I dealt with this problem when writing a similar plug-in. I meant to reply to your earlier email. You CANNOT do a direct connection to a per particle position attribute. I spent a great deal of time on the phone with Autodesk/Alias and even though the docs say you can connect to the per particle position you actually can't (If someone can correct me, I'd be very happy :). I solved the problem by using realflows solution, using an emitter to create/modify per particle position values. There may be other ways to do it, what are you actually trying to accomplish? Do you need to actually render a particle system? Alice Labs as a point cloud viewer for maya that actually just displays particles/colors in the viewport.
The plug-in I wrote dealt with molecular dynamics data. Essentially, I wrote my own particle caching system for maya that I could animate and interpolate, sounds like you want to use geometry within your scene to control a particle system. This could be done with a similar plugin... I haven't touched my code in a very long time, if I can even find it again... Have a look at some of my old threads on highend3d, they may steer you in a better direction. http://www.highend3d.com/boards/index.php?showtopic=224509&hl= http://www.highend3d.com/boards/index.php?showtopic=228795&hl= I'd have to take a deeper look into this, I've been meaning to convert my c++ plugin to python for fast prototyping and speed tests to give a more in depth answer. Also, I have yet to look at nParticles, this problem may have been solved already! ps, using a c++ plugin as opposed to expressions is roughly 100x faster (I found) when dealing with very large datasets, which is why I wrote it! Cheers, Justin On 3-Aug-09, at 1:57 PM, bendingiscool wrote: > > The reason I mention doing it this way is because the particle system > is really supposed to be handled this way, thats why they have their > own expression rules. > > Which is why it was a silly assignment. > > Chris > > On Aug 3, 8:59 pm, russell dines <[email protected]> wrote: >> Indeed, >> >> That part should be simple, but I'm wondering if it would be >> possible to do >> it on a PP basis. That way it prevents using up memory on many >> particle >> objects. >> >> Ta for the reply though :) >> >> On Mon, Aug 3, 2009 at 6:03 PM, bendingiscool >> <[email protected]>wrote: >> >> >> >>> Howdy russ! >> >>> Get on with that pesky project lol! >> >>> Not sctricly what your after but if you just sketch one particle you >>> can connect the outputs of the node to the nParticle's translates. >> >>> Obviously you would only want to do this for one particle otherwise >>> you would have a bunch of particles moving in the exact same >>> fashion. >> >>> Quick fix for a silly brief. >> >>> Toodles >> >>> El Bendino >> >>> On Aug 3, 10:11 am, "[email protected]" >>> <[email protected]> wrote: >>>> Hello, >> >>>> Sorry for a possible rookie question, but I've been ill for a while >>>> and had to take a break from my studies. This has made me forget >>>> some >>>> of even the simplest things :(. >> >>>> I've had trouble trying to connect node outputs to the individual >>>> particles position attribrute. >>>> So using the circleNode for example to make a single particle >>>> travel >>>> in a circle, how would you connect the nodes two outputs (x,z) to >>>> the >>>> particles position? >> >>>> The only way I can think about doing it is as follows... >> >>>> create a locator with 2 custom attrs. (x,z) >>>> connect the node o/p to the loc attrs. >>>> query the loc attrs, and place in varibles. >>>> query varibles and edit the particle position attr. >> >>>> However, this causes a problem of having to create expressions to >>>> constantly query the loc attrs and update the particles position >>>> per >>>> frame. >>>> It would be much simpler and by far quicker to have the node >>>> drive the >>>> individual particle directly. >> >>>> Does anyone know how this may be done? >> >>>> Group member Paul Molodowitch was kind enough to suggest the >>>> following >>>> to ammend individual particles to help me: >>>> particle('particleShape1', e=True, at='position', order=39, >>>> vectorValue=(-0.7, 0.428757, -0.938712)) >> >>>> Kind regards. >> >> > > --~--~---------~--~----~------------~-------~--~----~ http://groups.google.com/group/python_inside_maya -~----------~----~----~----~------~----~------~--~---
