Custom Particle Cache Writer/reader

[mayapower]

Hi,

Maya's native PDC (particle disk cache) cache is a huge waste of space and difficult to manage if you have more then one particle system in the scene. Second option is to write (PDB) files where you can specify particle attributes you would want to store but again you can't use PDB in place of PDC.

How about a custom particle cache writer/reader, in which you can write information you would be needing apart for position of the particles such as rgbPP, colorPP etc. Is it going to be tricky using Maya's API? Need some advise or if some one had already done this before then please share some information.

Regards

[joojaa]

QUOTE(mayapower @ 06/01/09, 11:34 AM) [snapback]308664[/snapback]
How about a custom particle cache writer/reader, in which you can write information you would be needing apart for position of the particles such as rgbPP, colorPP etc. Is it going to be tricky using Maya's API?

Would say it would be VERY challenging to get done with any sane performance yes.

[petershipkov]

Actually this is well supported.
If you use the default particle caching tools they will write all the available dynamic array attributes.
But you can call the command by yourself and provide only the attributes you want to save.
At some point in the past i wrote a handy little tool that allows you to do this easily in a simple gui.

Also, check the docs - this command is well documented there.

[mayapower]

Hi pshipkov,

Are you trying to say that you can write/store only selected dynamic array attributes in PDC files?
Could you please post you script?

Cheers

Prashant

[petershipkov]

How i attach files here ?

[joojaa]

QUOTE(pshipkov @ 06/12/09, 10:41 PM) [snapback]309380[/snapback]
How i attach files here ?

You cant put them up on your webpage!

[petershipkov]

True.

This is a rip of a bigger system that deals with particle caches and some other things.
This is the user code that operates in the current maya session only.
Try sourcing all the scripts before running the gui.
http://www.petershipkov.com/temp/pcm.tar.gz
It is very old so no guarantee that it works with nParticles.

[petershipkov]

Just remembered an old "trick" well more of a workflow with particles:
cache only position and velocity (if needed) and the rest of the attributes are still available for tweaking.
For example - you have your position cached particles but you can edit their color, sprite size and everything else.
I noticed that most people are ignoring this very flexible workflow, or at least not paying attention to it.
Not in the last place the cache files are much-much smaller this way.

[mayapower]

Hi,

Sorry for the delay. I have checked your scripts, seems pretty good way to do the job.
How ever I have thought of implementing particle caching in an alternate way. I am not sure if it's going to work or not.

1. You write "position" array of a particle emitter in an external file on per frame basis.
2. Create a simple emitter node using API.
3. Instead of generating particles, this node will read the data (position) from file based on frame number and generate
   the required data.

Need some light here...

Cheers

Prashant