Rendering Particles of Varying Size

[burgess3d]

Hi I'm using VRay version 1.50.00.14230 for Maya 2011 under CentOS and am trying to render Maya particles with varying sizes and it doesn't seem to be working.

I'm taking the following steps
1. Add an emitter on the grid
2. Press play until I see a few particles
3. Select the particleShape node, set render type to point and add attributes for current render type as well as radiusPP under Per Particle (Array) attributes.
4. Apply an expression to randomize radiusPP,
e.g. particleShape1.radiusPP = rand(1, 2);

VRay seems to pick up the pointSize attribute with no problems, I see it in the vrscene file under the GeomParticleSystem node, however, I don't see anything in the vrscene file to suggest that radiusPP is being picked up at all.

Am I missing something in the steps I'm taking to set this up?

Thanks for any help guys!

[vlado]

It looks like it is not implemented currently; will make a note to add it.

Best regards,
Vlado

[burgess3d]

Cool, thanks for the reply. One other thing, it seems like the Maya UI won't allow point size to be under 1 but V-Ray seems to respect point sizes under 1 when I change them directly in the vrscene before rendering. It might be useful to have this kind of control as an extra V-Ray attribute if the Maya UI doesn't support it.

Cheers

[Dan Andersen]

Any updates on the implementation of this?

Cheers,
Dan

[jbvfx]

It would be great to see this implemented. It's the missing piece for rendering particles in vray.

gogo Vlado

[vlado]

Working on it, sorry for the delay. Should be there soon, but if you need this urgently, let me know and I can bump its priority.

Best regards,
Vlado

[jbvfx]

Great. Please do bump the priority.

[vlado]

It seems to work fine for sphere particles; the Maya hardware renderer and mental ray both ignore the radiusPP attribute for point particles. It is not a problem for us to implement this, but it this will make it different from what you get with the other renderers.

Best regards,
Vlado

[jbvfx]

I know Mental Ray ignores radiusPP when rendering points. Mental Ray is never used for rendering points because it's incrediably slow. Vray is way faster at rendering points, and with the ability to control the point size, it could be a great particle render. So please implement it

It doesn't have to be radiusPP. It could be a custom PP attribute called "vrayPointsizePP" or something.

[jbvfx]

Bump.. Any news on this matter?

[Zdravko]

The radiusPP attribute is already supported. The feature will be available in the next service pack.
If you need it urgently please send us an e-mail to: support@chaosgroup.com

[jbvfx]

That's great news.

Thank you!

[NiallFlinn]

Hi,

Was this feature added, and if so, in which release? We've been using Vray 2.20.01 here and I don't see radiusPP having any affect on the render. I'm guessing I need a newer version...

Cheers,

Niall

[ivaylo.ivanov]

I think it's not there. Only in the nightlies. You must add additional VRay attributes group to make this work, it's called "Point size". I have forgotten to add this for the old particles though. If you use them, you can wait the next nightly or add one extra line to a text file. You must then enable "Point size pp" and optionally "Point size world" if you want to use world space radiuses.

[NiallFlinn]

Thanks for the swift reply!

When you say the old particles, do you mean non-nParticles? They are what I typically use unless I need the more advanced features of nParticles, so it would be great to have point size for them
Which text file do I need to edit and what do I need to put in it?

Cheers,

Niall