Particles and Scatter node

[tschwenke]

Hi,

Ok, that's too bad.

F. Rible created pyCloid and it seems that he used the Carrara Particle systems with quite some success. I try to get my fingers on the source code and let's see what will happen then.

Best wishes,
Thomas

[tschwenke]

Hi again,

I'm currently not able to get my fingers on the source code of pyCloid. So, I'm creating a small script in Houdini that will allow me to export particle positions into a CSV file that can be read by the Octane scatter node. I'll try it with Octane render standalone first. If it works well, it would be great, if you could incorporate the connection between Octane scatter node and Carrara.

Best wishes,
Thomas

[tschwenke]

Hi again,

Python did the trick. I loaded around 5 Million particles into Octane Standalone via CSV in an acceptable time frame. Quite amazing

The images is a render of about 300,000 particles.

So, is there any chance we can bring the scatter node into Carrara?

Best wishes,
Thomas

[protovu]

That is a really nice image, Thomas. Thank you for continuing with this.

[Sighman]

I'm adding the ability to include a scatter node to the plugin, including the ability to add multiple files to form an animation (like VDB animations). However, octane has a built-in particle that is highly memory efficient and allows you to specify additional particle properties such as particle size, uv coords (for color, transparency, etc) and velocity (for motion blur). I'm going to support an additional cvs format to include these parameters.

A particle csv must include a header row, for example:

Code: Select all

x,y,z,size,u,v,vx,vy,vz
1.0,1.0,1.0,0.001,0.5,0.5,0.1,0,0

X,y,z is the position of the particle (in octane coordinates)
Size is the particle size (in meters)
U,v is the UV coords and must be between 0 and 1
Vx,vy,vz is the velocity vector

Note that size, u,v, and vx,vy,vz are optional,

[protovu]

Thank you , Simon. This is so very encouraging.

[tschwenke]

Hi,

Thx protovu

That's very cool Simon! Adding other features to particles is a great idea. Thank you so much! I did not know of a built-in particle system...

In the future, it would be nice to have a PRT or ABC importer, as CSV files can become very big. 5 million particles can be easily 500 MB with a CSV file, whereas a PRT file is like 30 MB or so.

Best wishes,
Thomas

[Sighman]

I looked at PRT but the channel system is not easy to adopt. The only example PRT I found contained colors rather than UV coords so I would have to create some kind of mapping mechanism. I also don't know where to find details about alembic support for particles (although I admit I did not look very hard).

I could support a zipped csv format. That will reduce the size considerably.

[Sighman]

Do you have an example of an alembic (.abc) file that you want to render?

[tschwenke]

Hi Simon,

Ah, great

A zipped CSV would be a step forward, I think.

I created several files for you to have a look at.

The folder "1 Particle" contains files with only one particle present. I saved it as PRT and ABC. You find them with "no channels" and "all channels." All channels means that I activated them all for export. It's a simulation of 10 frames. In ABC file format, there are 10 files and another one, where I merged all ABC files into one. Most programs (IMHO) only support ONE Alembic file...

The folder "Particle flow" contains a particle flow in ABC and PRT. Here, I compressed the ABC file. I hope you can make the magic happen

https://www.dropbox.com/sh/cnjjft464g3l ... RB9Q_Q0_ha

Best wishes,
Thomas