Maniphest T39521

Render with two Blender processes on same computer: compression issues?
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Assigned To
Bastien Montagne (mont29)
Authored By
Colin (DerBen)
Mar 30 2014, 9:22 PM
Tags
  • BF Blender
Subscribers
Bastien Montagne (mont29)
Colin (DerBen)

Description

System Information
Win7
Nvidia Quatro FX 4600
ATI Radeon 3000

Blender Version
Not sure if it ever worked, but just tried 2.7

Short description of error
Open two copies of blender on same pc, only grabs render frame from one program or none

Exact steps for others to reproduce the error
I am trying to render a stereoscopic animation, I don't know if blender can do this (game engine can do stereo) in one pass..
Basically I have two cameras and a short animation, rather than waiting for left to render, I opened blender again on same pc and started rendering the right camera at same time.

I got a garbled mess with mpeg options, dropped/black frames for both files.
Then I tried PNG and noticed I was getting the same image for left and right (but individual manual shots were correct, render button, not animate) and then I started getting black frames while I was checking image output.

I think I even tried one blender copy on cpu and the other on cuda and still nothing useful.

If screen/vid card makes a difference, one blender window is on nvidia and the other is on the ATI card.

Thanks for your time! Love this program!

I'm not sure if this ever worked.. (I *think* I did it before though on an older version), but it would be great if it did

Revisions and Commits

rB Blender
AuditedrB6cd717e0a3c6 Fix T39521: Render with two Blender processes on same computer: compression…
rBAC Blender Add-ons Contrib
rBAC6cd717e0a3c6 Fix T39521: Render with two Blender processes on same computer: compression…

Event Timeline

Colin (DerBen) created this task.Mar 30 2014, 9:22 PM
Colin (DerBen) raised the priority of this task from to 90.
Colin (DerBen) updated the task description.
Colin (DerBen) added a project: Add-ons (Community).
Colin (DerBen) edited a custom field.
Colin (DerBen) added a subscriber: Colin (DerBen).
Bastien Montagne (mont29) lowered the priority of this task from 90 to 30.Mar 30 2014, 10:39 PM
Bastien Montagne (mont29) added a subscriber: Bastien Montagne (mont29).

Well, if you render to the same (video/png) file from two different processes, no wonder why it fails… If you render in two different files, I do not see why it would break.

Please attach small .blend file demonstrating the issue, with precise steps to reproduce it.

Colin (DerBen) added a comment.Mar 30 2014, 11:42 PM

HauntedHouse19BUG.blend1 MBDownload

Nope, I render to left and right files for videos or sequences. Basically I have a left and right video, and in turn a left and right image sequence rendered.

Left.mpg and Right.mpg

or

left001.png
right001.png
left002.png
right002.png

Anyway, there's cameraL and cameraR

Open blender twice, load the attached file in both.

select cameraL in one and cameraR in the other,
CTRL+num0 on both windows

you can try PNG or mpeg

hit animate and watch the output. (you might have to set an output folder)
The files left and right should not be identical, but off by a bit.

Colin (DerBen) added a comment.Mar 30 2014, 11:44 PM

Adjust Output folder and name as per the camera!

Bastien Montagne (mont29) renamed this task from Rendering technicality to Render with two Blender processes on same computer: compression issues?.Mar 31 2014, 8:38 AM
Bastien Montagne (mont29) edited projects, added BF Blender; removed Add-ons (Community).
Bastien Montagne (mont29) raised the priority of this task from 30 to 50.Mar 31 2014, 8:41 AM

OK, I can confirm the issue… I really wonder what happens here, sometimes you even get pictures which mix both left and right views!

Bastien Montagne (mont29) claimed this task.Mar 31 2014, 8:45 AM

Ah, in fact, think I know what’s happening here… You are using full buffers for OSA, which means Blender has to save them in temp files. Obviously, it generates same names for both right and left cam… Will see how to add some kind of "salt" to those, using the PID or timestamp e.g. maybe?

Colin (DerBen) added a comment.Mar 31 2014, 8:51 AM

"...sometimes you even get pictures which mix both left and right views!"
Some would call that modern art...

Thanks for the speedy responses!

Bastien Montagne (mont29) edited this Maniphest Task.Apr 2 2014, 12:09 PM
Bastien Montagne (mont29) changed the task status from Unknown Status to Resolved.Apr 2 2014, 12:09 PM

Closed by commit rB6cd717e0a3c6.

Bastien Montagne (mont29) edited this Maniphest Task.May 12 2014, 4:46 PM