Can you figure this out?

[jucaro]

Here's the scenario:

 

I compute IR map using Multiframe incremental. Afterwhich I render the

entire animation to a render farm using Backburner. Everything starts out fine, but after sometime the renders are a bit splotchy, and some shadows

are left behind after some frames.

 

I tried re-rendering the problem frames locally, using the same IR map

that I saved before, the frames render fine and correctly.

 

I'm using VRay 1.09 r

 

I issue the jobs from a windows 2003 server. The farm workstations are windows XP Home edition on a ntel P4 HT 3.0 GHz utilizing 100mbps lancards

 

Some insight would be appreciated

[Crazy Homeless Guy]

i would check to see if the bad frames are always coming from the same computer or same computers.

[jucaro]

CHG: I've already done that. but the render errors happen randomly. Thats why I tried re-renderng the problem frames from a single PC and not use Backburner, and it looks fine.

 

The error comes when I use backburner and leave the rendering overnght. To my horror to find the next day to find messy rendered frames.

 

If this helps, some more info on my scene.

 

There are lots of moving objects. Truth be told, its not an architectural animation, but a product animation. I've always relied on my workflow for rendering architectural animations. Sadly, it doesnt apply when rendering product animations.

 

Sorry if this may look like I'm posting on the wrong Forum.

[Crazy Homeless Guy]

i think that might be the problem. lots of moving parts rendered across multiple machines.

 

moving objects in any type of radiosity solution usually causes problems.

 

you rendered the irradiance solution, then applied it before you sent it out using backburner. an irradiance map can only store global illumination information for still object. if there are moving bjects in the scene, then it needs to recalculate the illumination for that object when it moves. and that is where your splotches are being created. every time a solution is generated it is slightly different. so from one frame to the next, there will be variances in the solution that will appear to dance around.

 

when you render on one machine, the same solution is being re-used, and built upon. so the moving object from one frame to the next is more consistent because it is using the solution from the previous frame.

 

if you can get the rendering done on one computer, that would be the easiest solution.

 

if you need to use network rendering, i would suggest to exclude the moving object from the irradiance solution, then use lights that only effect them, so they render using more of a scanline method, while the rest of your scene is still globally illuminated. this is difficult to set up, but it shuld produce smooth results.

 

get a second opinion, but this is my guess at what is happening.

[Da_RoCk]

Thanks CHG.

 

What I did in the end was some what crude.

 

I got each machine in the farm to render a range of consecutive frames. I did get clean and predictable results at the expense of lengthy render times. Up to an hour for each frame. I can't be choosy anymore as deadlines are fast approaching and I've already wasted 2 days trying to figure this out.

 

Well, if anyone has some clever ideas, they'd be very usefull for future projects.

 

 

--and we all can avoid rendering nightmares.

[jucaro]

OOps..I forgot Ramir was previously logged from this computer...

 

My bad.