Mathieu
I got some issues trying to disk cache deformed particles, while the deformed system is connected through worldPosition -> deformedPosition everything works, but if I break that connection, position and velocity cached data are accurate but other attributes as radiusPP and rgbPP are set to 0. I though I could just cached position and velocity and then recreate and overriding  my other attributes (radiusPP, opacityPP,... ) and recache a second time the deformed particle system, but it 's not working (maya disables "use particle cache" before launching a new one).
If someone as an idea :)

Mathieu
Quote 0 0
pshipkov
The entire post sim modification pipeline for particles is bug ridden.
It takes extra technical knowledge to make it work.
The simple thing is to cache the original particle node and keep the deformed one "live".
The reason for the empty rgbPP and radiusPP stuff is that the deformed particle cache is inheriting these from the original one on the fly and the cache system apparently fails to notice that.

There is a tool in SOuP called nPCM that allows us to specify exactly which PP attributes we want to cache. I am wondering if we can use it to cache position/velocity of the deformed particles and then only to append radius/rgb/opacity data from the original shape to the cache. But this is bad workflow because it requires extra work. For now try the first suggestion.

Quote 0 0
Mathieu
Thanks for the reply, the only problem is that I really need to cache all the attributes of the deformed particles system cause we use a data expansion tool that needs those attributes to extrapolate new points from pdcs.
But I think I have found a tricky and dirty solution :)
I cache my nparticle original simulation with a isCreatePP attribute that I set true at creation, I used that attribute in a global expression to emit from newborned particles into my ToCache particle system and I use my Deformed particles as goal for the ToCache system. 
(I use a deformed particle sytem connected to my original just to check if it works with an intermediate deformed particles system)

Mathieu
Quote 0 0
pshipkov
That's a good solution too.
Quote 0 0
jibadajaba
Where is isCreatePP attribute...I don't see it.  I opened up the AddDynamicAttributes and looked.  Am I just not seeing it?  Did you set this up yourself?  I feel like a 101 student watching two masters talk.  Which actually is not too far from the truth.  I've come a long way but I really can't figure out your solution.  I want to learn.  Please explain this method further.  Much thanks.
Quote 0 0
fedest
hy Peter really thanks you for your work and inspiration(that's my first post on this forum).
I'm having a similar trouble whit this maya bug on deformedparticleshapenode connections.

Instancer on maya will use correct particles position on a deformed sistem only if it's connected to the deformedParticlesShap node , the one who loose PP attributes. 

Is it possible to make a connection between PP attributes of the ParticleShape node,
the position from the deformedparticlesShapenode, pyping them into a pointNode , the one who will bw generating data for an instancer?


i've been reading lot of treads around , can u help us finally solve this problem?

how to keep PP attributes inside an instancer connected to deformedparticleShapenode?
Quote 0 0
pshipkov
You can connect the PP attributes to other nodes, but PP attributes on particle, nparticle, ncloth, nhair nodes cannot accept input connections.
I flagged this to developers and hopefully they will resolve it at some point later, but for now the only way to do that is from within particle runtime expression, like this:

float $myDataPP[];
if(id == 0) $myDataPP = `getAttr someNode.someArrayAttr`;

Quote 0 0
pechart
Just to point out our solution for this:

We just pipe the position to an instancer with an arrayToDynArrays. The other stuff, like objectIndex etc comes from the original particle system and gets daisy chained into the arrayToDynArrays node.
Seems to work great for now. Hopefully vray will be able to read the rgbPP values somehow...
Quote 1 0
nezus
After struggling for a while I finally managed to transfer my attributes to the deformed Particles. Here a screen shot of the setup (note to myself and anyone interested)

deform_particles_instancer_soup.png 
But since my deformed particle is not directly connected to the instancer, the instancing options are disabled and I can't choose which attribute to use for aim, scale, rotate, frame...

Any idea ? Thx a lot
Quote 0 0
pshipkov
can I take a look at your scene ?
Hard to say by just looking at the screenshot.
Quote 0 0

Add a Website Forum to your website.