Vray error message can't figure out!

[Devin Johnston]

I'm in the process of saving out my LC & IR maps, I've submitted the job via Backburner to 10 render nodes all of which are clones of each other. They begin rendering out the maps with no problem but after a while I start getting "could not save irradiance map" errors from random machines. Naturally I figured this is a problem with the server I'm writing the data to so I switched to another one with the same results. I've had this problem before but the issue seemed to fix it's self, however this time I want to figure out what's causing the problem. I know the server my machine is writing to is on the same switch as they are, it's running a server version of windows and has plenty of drive space. Anyone have any ideas?

[Alyosha]

I'm not sure this has anything to do with it but it may be worth checking it out, as a european using special charachters I had problems exporting vray proxy objects into directories that contained european special charachters in their names, which is completely odd as I had never had any similar problem with any kind of program lol...

 

I see you're from US so by default you prolly shouldnt have such problems but maybe you're using some sort of other charachters that vray doesnt like or somesuch.

 

Well thats about all that I can think about:-)

[Devin Johnston]

I don't think it's a problem with characters because if I let one machine render out the LC&IR by it's self there are no errors but the minute I put two or more machines on the job it starts to error.

[Ricardo Eloy]

Do you get the same error when rendering via VRay's native DR?

[Devin Johnston]

I haven't tried rendering the maps using DR from my main machine yet, I'll give that a try.

[Ricardo Eloy]

I haven't tried rendering the maps using DR from my main machine yet, I'll give that a try.

The only thing that is kind of a pain with VRay's DR is that you'll probably have to copy all your bitmaps to a local directory with the same name in all machines (i.e., something like C:\temp), so all machines can find the bitmaps without having to rely on the network (most DR problems are because not all machines can find the bitmaps on the network). Also, you'll have to use the Asset Tracker to redirect the bitmaps you used in your project to this new temp dir on your machine prior to rendering.

[Devin Johnston]

I use DR all day every day, 10 nodes pulling maps from another network drive and I've never had any problems. What I don't understand about the process is when a node fails to write the data that particular frame is re-rendered, when this happens the final light map sometimes gets messed up and the animation won't render correctly. I can't wait for a single machine to render this stuff out it takes way to long so I've got to figuer this out somehow.

[Crazy Homeless Guy]

What mode are you using for the Irradiance map? I nearly always use multiframe incremental for fly-through's, and I was always under the impression that the light solution done in this way had to be done on 1 machine. Perhaps things have changed with some of the new light solutions, or I have missed something?

 

I do use DR for generating light passes, but I always do them on 1 machine. this speeds things up, but I don't think that the calculation of LC will use multiple machines while DR'ing.

 

As for the error... To me that sounds like multiple machines are trying to write to and save to the file at the same time, which would generate the error since the file would be in use by another machine, but that is just a guess.

 

I think you could generate separate Irradiance maps, and then combine them with the Irradiance map viewer, but I would just as soon generate them on one machine unless it is incredibly long in the calculation time.

 

Ricardo, ...As for DR, I am also typically able to pull network textures with no problem. Every no and again it messes up and gives me black buckets, but for the most part it is fine. Are you UNC'ing or DFS'ing your texture paths, or are the drive letter mapped? I always DFS or UNC the paths.

[Ricardo Eloy]

Hey, Travis! I've done everything by the book, and still had issues every now and then. The only way that worked 100% of the times was to make a local copy of all maps. After that (we even have a script that copies all the maps automatically when I log as a "render" user), it works like a charm.

About calculating the solution using multiple machines, I think VRay's DR does a pretty decent job using all machines to calculate IrrMap and Light Cache. And the main machine mixes them all up, creating one single solution. Not sure how that works via Backburner, though.

[BrianKitts]

I'm pretty sure the only possible way to have multiple nodes write out an irradiance map is when you are using the "animation" irradiance mode. Which writes out an irradiance map for every frame so that you don't have an error of multiple machines trying to write to the same file simultaneously.

 

Only thing I could think of to cause Devin's error is if he's using a non animation irridiance mode in which case multiple machines would be trying to write to the same file name and fighting over it. Which of course wouldn't work even if they could because they would just constantly keep overwriting the same file.

 

If you don't have any moving geometry or lights, multiframe incremental is the best way to go (as Travis mentioned).... which has to be calc'd on one machine. But you can use DR to run that calc on your single machine. If you need to queue up a list of jobs you can use BB to set a render list, but I also set them to only run on my machine. Then DR works great through BB. I thought with 2.0 vray was able to pass a list of available DR nodes to jobs through BB, but I've never gotten it to work.

 

Rick, I used to have similar problems with DR, but in the last year or so it's been running solid for me without any tricks. Sometimes nodes drop, but I've never had one run and drop maps.

Edited January 24, 2011 by BrianKitts

[Ricardo Eloy]

Well, maybe the new release has it sorted... I just did not have the will to change my "pipeline", lol...

About calculating the IrrMap in only one machine, using VRay's DR has always worked, even with Single Frame calcs. My machine simply shows all machines calculating what appears to be one single pass (even though I'm calculating, let's say, 4). They seem to be all calculated at once, using all processors at once. And, to be honest, I don't think calculating in animation mode would prevent the machines from trying to save the same file at the same time. It's the same as Single Frame, only several times one after another.

[Devin Johnston]

It's so strange because I did let all 10 nodes calculate LC&IR using multiframe & flythought for years and it worked. I guess I'll have to try it another way now, I hope it's not much slower.

[Ricardo Eloy]

They should still work, Devin. I mean, I've never heard DR could not be done with specific modes.

[iancamarillo]

Hi Devin, has your question been resolved? I'm experiencing a similar error with a file I received from China. The file does have textures and proxies that were created using Chinese characters. After the transfer to our network, the files were then renamed to English characters so they are now called something like "¦OOIA+-B.jpg". I believe this may be the problem.

 

For my flythrough, I use irradiance (medium animation) and brute force and render every 10 frames. I submit this file to the farm and select only my machine to calculate the vrmap. As soon as 1 frame is written to the vrmap file, I submit the final render to all available servers on the network (we have only a couple of machines so the final render doesn't catch up with the vrmap render). This way I don't wait for the vrmap to finish before submitting my final render.

 

When reviewing the frames, I've noticed a flickering/color splotching error on all the machines except mine. My machine has the Google language bar installed and the others don't. Maybe my machine renders correctly because of the installed language bar?

 

I did get a "could not save irradiance map" error in backburner half way through the vrmap render. Perhaps the renders flicker because of a corrupt vrmap? But that doesn't sound right because my machine rendered every frame correctly from start to finish.

 

I also thought my workflow of submiting the vrmap to the farm and final render right after could be the problem. But it's always worked fine before. I assume the final render is only reading the vrmap? I've also had error messages on our slooooow network (opening jpeg files!) saying"could not open because the file is currently in use". So I kinda think it's a network problem. So I guess I should wait til the vrmap is completely finished before submitting the final render? That sucks. Does anyone else see any problems this way?

Edited April 4, 2011 by iancamarillo
vrmap in use?

[Devin Johnston]

No I've never figured out what was causing it but it doesn't happen with every job so i don't really know. As for your problem it sounds like the final animation is starting before the pre-pass has completed, that would result in lots of flickering if that's what's going on. In order to make sure this doesn't happen make the final animation dependent on the pre-pass that way it will wait until the pre-pass job has completed before starting. If that's not the problem then you could have some machines on your network that can't read the light maps for some reason.

[iancamarillo]

Ok cool - thanks. I didnt know about the dependencies in backburner.

 

but why would it flicker? if the vrmap "blends" the lighting depending on your "nth frame" settings, why couldn't you read from the vrmap as it's being created? We dont have a large farm so the vrmap is nearly done rendering when the final render is still on the first few frames. know what i mean?

 

i dunno - i guess i just don't understand how it works under the hood

Edited April 4, 2011 by iancamarillo

[Devin Johnston]

Well vray is building the map as it goes along and then it blends it together so if you start rendering before it's done there will be parts of the model that don't have any light information. Regardless of what it's doing technically it's a good idea to let it finish before you start rendering the final animation just so you can avoid problems like this.

[iancamarillo]

cool will do. by the way, I installed the google language bar on the manager machine and the renders are working now! **crossing my fingers this fixed the problem**

[wuhoo]

Sounds like a UNC (Universal file Name Convention) thing (google it!). We have lots of similar issues with Vray DR not picking up buckets or unable to save IR and LC maps because the network path can't be seen. Proper UNC pathing allows VRAY/Max and Backburner to properly pick up all texture maps without resorting to copying all the texture maps to the local machines. Hope that helps!