Any known issues with max 2012 bitmap IO configs (mainly EXR) and Vray?

[joconnell]

Hi Vlado,

Bit of a stupid one here but I'm checking up on a few issues at the minute. I've got a load of shots that come from a matchmover who renders a TGA sequence just to check alignment / tracking in the scanline, then loading in a vehicle asset, lighting and rendering out with Vray using the main max buffer, and a lot of render elements all going out as individual sequences. I'm getting two glitches with this:

1. All of the passes go out name as EXR files but the render elements are actually TGA files named as exr. The render elements are correctly set to go out as EXR, normally done by un-setting all filenames for output, then being set by script as shotname_objectname_renderElementName_###.exr but come out with bad data.

2. Sometimes our render elements come out with the entire list of 3dsmax g-buffer elements embedded in them, not even the useful vray elements that we've chosen to ad, but the following:



It isn't as big an issue as the first since the RGB data is still fine, but it means that the EXR files need to be stripped.

I've posted a question on the Deadline forums and they can't reproduce it, but someone else mentioned that there was an issue with max 2011 and vray where bitmap IO configs could get messed up at times and the scene file needed to be switched to another format, saved and closed, reopened and set back to what you actually wanted before rendering your final images. Apparently this bug was only fixed in max 2013 but I can't find any leads on it.

I'm trying to chase this down to solve future headaches, Are you aware of any known issues between max 2012, vray and this bitmap io issue?

Cheers!

John

[vlado]

Are you using the V-Ray VFB for this, or the regular 3ds Max one?

Best regards,
Vlado

[joconnell]

The regular max one, I'd much prefer to use the convenient vray vfb and embedded channels but our compers have found that even with the datawindow and Scanline zips, individual sequences are still a bit quicker, especially since they can turn off bits they don't need.

[Zdravko]

1. All of the passes go out name as EXR files but the render elements are actually TGA files named as exr. The render elements are correctly set to go out as EXR, normally done by un-setting all filenames for output, then being set by script as shotname_objectname_renderElementName_###.exr but come out with bad data.

Would it be possible to send us an example scene with that issue as well as the script that you are using to save the render elements?
Also, does the problem persist only when using Deadline? Which V-Ray version are you using?

[joconnell]

Yes! It actually turns out that this is a deadline issue and nothing to do with vray. It's got an option called "enable local rendering" which means that the frames render out to the render nodes temp directory first and then copy to the final output directory as a way of keeping rendered frames if there's an issue saving. It turns out though that deadline changes your max file as it's submitting to it's repository (which you never see it do so you aren't aware of it) to make your exr files save out to the local drive, but it doesn't take all of the EXR options that you've set. So that "enable local rendering" option was what was doing the damage - deadline seems to have a few "helpful" options which are nice features if you know about what they're doing but like in this case they're causing a lot of problems - they'd maybe be better turned off by default.

False alarm, Vray is still fabulous

Also the TGA error is apparently some kind of internal problem with max that came in with version 2011 - possibly related to their new cebas EXR plugin? It seems that even though you set a file type for output, if there was a previous different file type set the new type doesn't "stick", so you end up with the old file type with the extension of the new type of file. Max error for this one but we're stuck with it as we can't move off 2012 for this project.

Much appreciated for following up Zdravko!

[Rens]

It's the way max handles bitmaps in the elements. For the main file output it's enough to change the file string, but for the elements you need to replace the actual bitmap.

The steps are, in this order:
1. Make sure your folder exists.
2. Get the full EXR path and filename as a string.
3. Make a 1x1 pixel placeholder bitmap with the name string as filename. It doesn't have to be the exact same name as the actual EXR, I just add a "_TEMP" suffix to the bitmap name (before the extension).
4. Save the bitmap. This is important.
5. Replace the .bitmap property of the element with the placeholder bitmap.
6. Use .SetRenderElementFilename and set that to the actual, correct EXR string.
7. Close the bitmap.
8. Delete the placeholder bitmap on disk.

This goes for any changes you want to make to each render element, like bit depth.
I have a script that does this, I'll see if I can dig it up.

[joconnell]

Cheers for the tips again Rens, thankfully we haven't had this issue in a while but I'll definitely integrate your workflow until we find another file that has this issue consistently enough to test and eradicate. Where you working in london btw - somewhere like nexus?