Error writing file from VFB with Backburner

[simmsimaging]

I ran a render test locally and it was fine, and lo-res ran fine via backburner, but when I ran a render in high-res via Backburner I ended up with an empty file. It's happened twice, after 4 hours of rendering.

The error in Backburner server window says:
ERR: Task Error: (Vray) Cannot write output image file (the file name/location)
ERR: (Vray) [VFBCore:: SetRegion] Error writing render region to raw image file

I am actually using RPM to render and save, but it should be saving to .exr, not raw, and the file it generates is an exr, it's just blank.

Any ideas why it would work fine in lo-res but not high res? Seems weird to me.

b

[vlado]

Are you saving to a network location? You can try saving locally and see if it helps. There seems to be some issue with the OpenEXR library that we use in this case. The problem seems to be the time of the rendering, not its size in particular. The issue seems to happen when the file is kept open for writing for longer periods of time. There aren't issues when writing to a .vrimg file though.

Best regards,
Vlado

[simmsimaging]

Ah crap, that figures. I just dropped 100$ on ProExr and it looks like it's a dead end for me. I do use a network location and it would be difficult to avoid. I was really looking forward to the efficiency of having all the passes in one file that opened directly into Photoshop. I can use vrimg instead, but then I have all the steps of converting out the passes and manually re-loading them into a single file. At that point I might as well just render the split passes and save the vrimg conversion.

Is this specific to layered exr files? I have been using non-layered exr in this workflow without any problems.

[rivoli]

I can use vrimg instead, but then I have all the steps of converting out the passes and manually re-loading them into a single file.

i think you can convert vrimgs in single, multi channels exrs. still an extra step I know, but you won't have to manually load every channel in ps.

[simmsimaging]

Got it - it works fine automatically. Grant has this already well covered with RPM too: you can set the options in the Vray output to automatically fire up vrimg2exr and have it extract the exr from the vrimg file upon completion, so if I use RPM the extra step is totally transparent, which is great.

Thanks for the tip!

b

[simmsimaging]

Fired up a render last night and had the same error come up and the render crapped out again, but I had chosen to write a VRIMG file as the final. I am going over the Vray and RPM settings this morning, but is there any chance this error could happen with VRIMG files as well as EXR?

b

[vlado]

Is there an error code next to the message? If yes, what is it?

I haven't come across a case where it happens to .vrimg files, but there is always a first time... The other option seems to be to write to the local disk which also appears to solve the problem. In any case, I noted this down and we'll try to reproduce it here.

(Technically, with the .vrimg file you can try opening the partial render and just fill in the missing part, but I don't know how useful this will be).

Best regards,
Vlado

[simmsimaging]

There doesn't seem to be an error code, it just says the same things as quoted in the first post.

I'm running it again right now, with no DR, and I reset all the save options in RPM/Vray to see if there is something funky there instead. It's just hard to tell without hours of rendering I know I never had this problem rendering with split channels instead of a layered EXR, so I may eventually give up and go back to that.

Thanks for the tip on the VRIMG, but it crapped out having rendered a fairly small (and very odd shaped) part of the image, so I basically just have to do it all again

b

[vlado]

Ok then; in any case, I think I figured out a fix for this, so it should be coming fairly soon.

Best regards,
Vlado

[simmsimaging]

Awesome - beats me giving up for sure!

Thanks Vlado

[simmsimaging]

This time it worked fine - rendered for 6 hours and wrote the VRIMG fine. I am wondering if the RPM save dialog may have activated the Max save option too, in which case it may have tried to save an exr as well as the vrimg. For sure it was off this time, but not sure about last night. In any case, if you have a solution to the root cause then it will soon be a non-issue.

b