Particle Amount Rendering

[Thomaskl]

Hello@all,

well, this time i do have a little problem with particles and Vray Motion Blur. I am asking myself how-many particles can be rendered with MotionBlur (geom-Samples>=3).
Its a general questions how vray handles the amount of triangles in the szene, i think. If the geometry would be loaded into the Ram only for the active bucket, you would be able to render a much higher polycount. But -for me- it seems, as if vray caches the whole Geometry before starting with first bucket. (Think, all renderers do so, and it makes sense in most cases). Well, so i would like to know, how to render really large numbers of particles with vray and a good looking motionblur.
In my special case i have to render more than a million particles with MB, but only as MattePass without any lighting, and currently i have no idea, how to solve the Vray-Error-Message in the Preparing-Objects Phase. "Preparing Camera Samper", Unexpected Exception", etc...

So, my idea was only to cache the geometry for the one active bucket only. By using the bucket-Size, you would be able to control, how many particles are being cached.

Thanks for your answers,
Regards,

Thomaskl

Head of Animation
MagnaMana GmbH

[dimo]

Hm,

for normal geometrie setting the default geometry setting in the system tab to dynamic should do exactly that. No idea if this applies to particles as well.

Dieter

[studioDIM]

If you're using ParticleStudio, make sure in its render settings you specify "Mesh per particle".
Maybe then with the dynamic raycaster it will load only the particle present in the bucket...
I haven't tried it in VRay, but succesfully did so with Mr on an old job.

Re,
Lele

[Thomaskl]

mmh..yes, it says so in the help files...I tried several tests, and it does not seem to be a solution for this "particular" case
I will render the particles in passes now, and let the comp-team do the rest
I am using standard-max particle-systems, not pflow...
The proxy meshes of vray dont work with particles...(of course, they don`t)
Well,

Thanks for your answer,
Regards,

Thomaskl
Head of Animation
MagnaMana GmbH

[studioDIM]

i guess the standard particles are one single "mesh object", as far as rendering goes.
Passes will definitely be more economic in this case :P

Lele

[Thomaskl]

Thanks for your answers,

but i would be intrested, how vray handles PFlow Particles. Perhaps someone has an idea ?

Regards,
Thomas

[DaForce]

I have had no problems rendering pflow particles with vray moblur.. true it wasnt all that much... probabaly 5-10k i think (cant remember may have only been a few thousand) but anyway, it rendered fine a little slow.. but still rendered fine.
I found post to be a better alternative as long as you render out the correct channels and options you should be fine.

Also i believe the newer version had a fix to render pflow particles better with vray moblur.. not sure if it was the 1.47 or 1.48 version of vray tho.. sorry

[Thomaskl]

another try

Hello Friends,

I could finish my last job with rendering in passes. But now, i want to crack that nutshell, with the particles...

So, here is my question...how far can you go with the amount of particles..in connection with the build in Pflow.

I rendered 5 000 000 Particles as Tetra. Tetra has 4 sides, so there 20 000 000 faces in my rendered image. I did use no lights, no materials, nothing else than particles....Memory goes up to 2.8GB and it still renders fine...

But with 6 oder 7 000 000 particles it crashes even on our best machine. Well, some stats:

Dynamic Memory set to 400
Pflow set to "Mesh per particle"..

The Problem seems to be before the geometry comes to Vray. Max build`s it`s Particle Tree completly (Ram goes to 3GB), and then max does crash, before Vray even starts....

Well, this is quite stupid. Is there any way to build/evalute/calculate only the particles for a single bucket?. Of course, max doesn`t think in buckets, which makes the problem...this suXX. 20 000 000 faces are a lot, but if you do something with many particles and spawning and trails, etc...making nice smokey trails....you will need much much more than this amount....

So, it`s a big limitation when you`re working with particles...Of course, i could use some volumetric renderengine like Afterburn, but i want particles....Many Many Many Particles...just faces...

the big companies make it to render Millions and millions of highly complex objects in one pass...i just want faces, and can`t do it...


Please,
anybody an idea ?

Regards,

Thomas

[re:FORM]

Sorry to dredge up this old thread, but I have a few things to add.

Sounds like what you are looking for is Krakatoa, a point renderer from Frantic Films.

http://www.franticfilms.com/software...atoa/download/

Looking at that renderer it made me wonder whether vray could have a particle primitive object that would render super fast in the same way as krakatoa works (ie particles are points, not geometry).

Unfortunately we would still run in to the memory limitations of pflow and max.
It looks like the only way to go is to make multiple flows, and to render them in passes and composite.

---------------------------------------

I'm trying to determine my particle limit with vray at the moment.
Simple scene, no materials, no lights, just 12 PF_sources each producing 100k particles(tetra).

- Renders in scanline in 4:07m. No problems.
- Crashes vray with an "UNHANDLED EXCEPTION : Memory allocation failure" message. The max render dialog shows P memory hitting about 1.2gb before the crash. Vray memory set to dynamic (1.4gb!, although I did try other smaller amounts higher than the default).

I'm running vray 1.5 on XP, 32bit, Max 9.

Any suggestions to why vray fails before scanline with particles?
Any ideas on how I can increase either max or vrays particle limit? (and I dont mean the particle limit you set in the pflow system dropout )

[re:FORM]

haha, well whaddyuknow.... As soon as I posted this, I got vray rendering the particles fine. I had to change to particle type to shape-facing.

joy.

Still, I'm open to hear other people's experience and suggestions with pflow and vray (except for the MB issues which seem to feature alot on the forum already).

[vlado]

Well, get a 64-bit machine/OS/3dsMax and you'll be fine

Best regards,
Vlado

[re:FORM]

hehe, thanks vlado I had a feeling that might be the answer.... unfortunately not possible till february as I'm out the country....

ho hum... looks like I'll have to continue on my hobbled system!

[re:FORM]

Just for other peoples reference, I've found that I can safely render up to 1440000 particles (facing) with just 2gb ram.