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Author Topic: Forest rendering error  (Read 2293 times)

Kai

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Forest rendering error
« on: September 07, 2016, 04:45:08 PM »
Hi, I'm getting a lot of errors in my latest project using forest pro. Every few frames parts of the forest are being clipped. I've been dealing with it by re-rendering bad frames but it is very time consuming and I wonder if this is a bug or a problem in my settings that can be fixed. I uploaded a zipped up max file and a windows media file that I hope you can take a look at here: ftp://ftp2.dot.state.mn.us/pub/outbound/MetroWatersEdge/Visualization/Kai/forest/

Thanks in advance for your help!

Kai

NCViz

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Re: Forest rendering error
« Reply #1 on: September 07, 2016, 05:37:32 PM »
I have been struggling with this issue for some time now.  I'm glad to see it's not just me.  Are you rendering to a farm?

Kai

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Re: Forest rendering error
« Reply #2 on: September 07, 2016, 05:45:47 PM »
Hi NCViz, I was just looking at your post with the same issue and was about to reply to you but you beat me to it! Yes, I'm rendering on a farm and there is no pattern to which machine renders bad frames. I haven't tried to reproduce it locally because that would take way too long. This has to be a bug don't you think? I never had this problem before version 5. When did you start seeing this?

By the way, are you with the North Carolina DOT?

NCViz

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Re: Forest rendering error
« Reply #3 on: September 07, 2016, 05:56:43 PM »
I don't recall exactly when it started but version 5 sounds about right.  Yes I'm with NCDOT.  Guessing you are with MNDOT.  We should get together sometime to compare notes.  That is some nice work you have there.

Kai

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Re: Forest rendering error
« Reply #4 on: September 07, 2016, 06:05:20 PM »
Thanks! here is my email: kai-jurgen.link@state.mn.us
Let's compare notes, I'd like to hear about what you guys are doing.

Michal Karmazín

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Re: Forest rendering error
« Reply #5 on: September 08, 2016, 10:25:30 AM »
Hi,

Sorry to hear you're facing those troubles and thanks for all provided assets. We've been analysing your scene and it seems to be rendering correctly here (though we're missing some assets), but it's touching Forest Pack & mental ray renderer limits.

If possible, I would suggest you to check network rendering log files for any errors (thought unfortunately in most cases they are too way generic). It is also recommendable to increase the verbosity level of the log files (to get more overall info about what's happening).

Actually, the mental ray integration is overall problematic as for example mentioned in this "Strange Problems with DBR" post regarding another topic (an older DBR issue):

"Well, the real problem with Mental Ray is that it is not an Autodesk product either. The engine was originally developed by Mental Images, and recently purchased by NVidia. Unfortunately the integration with Max always was very problematic (and is not very well documented).

Probably this is the reason that 80% of our customers use other render engines (V-Ray mainly)."


Unfortunately, there is not much more we can do about it. Feel free to check another "Network rendering stops after first frame" post related to the mental ray renderer issues:

"Regarding Mental Ray, from our data we know that it's barely used by our customers. Most of them use V-Ray, Corona and other renderers. Probably it's not only a technical question, but also the lack of support from Autodesk.

Mental Ray is not a bad product, but is poorly integrated with Max, and when a problem arises there is not anyone to ask for help."

Best regards,

NCViz

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Re: Forest rendering error
« Reply #6 on: September 08, 2016, 01:23:59 PM »
The only flaw I see in this diagnosis is the fact that this issue is new.  It has only started with the last few releases.

I would love nothing more than to dump Mental Ray and Backburner.  We have 5 workstations and 30 render nodes which makes this cost prohibitive however. And yes Autodesk support for these products is worthless.  Do you have any plans to support the new ART renderer delivered with 3ds Max 2017?
« Last Edit: September 08, 2016, 01:30:47 PM by NCViz »

Michal Karmazín

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Re: Forest rendering error
« Reply #7 on: September 08, 2016, 01:48:19 PM »
Hi,

Sincerely, hard to say if the ART render engine will be supported soon (most probably not at least until 3ds max 2018 will be released). Actually, there is no SDK for the Autodesk Raytracer Renderer (ART) and it doesn't seem to have instancing capabilities required by our plug-in, but we'll evaluate its implementation for future releases. It'll depend on the ART renderer future development process (its future capabilities), because of mentioned actual limitations. Thanks for your comprehension.

Best regards,

iToo

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Re: Forest rendering error
« Reply #8 on: September 08, 2016, 05:54:43 PM »
The only flaw I see in this diagnosis is the fact that this issue is new.  It has only started with the last few releases.

We have introduced several changes in our latest releases to solve other MR issues. Unfortunately we cannot know if there is something wrong in our code, or what is the problem exactly.
Without the help of Autodesk, NVidia or whoever is in charge of MR now, we only can check our code or by trial an error (tried both many times unsuccessfully).

And go back to the code used in FP4 is not an option either, because then other fixed bugs would arise again. We feel on a dead end with MR...
Carlos Quintero
iToo Software

Kai

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Re: Forest rendering error
« Reply #9 on: September 09, 2016, 04:02:27 PM »
Thanks for analyzing the file. I don't think the other mental ray examples you gave are related to this. Not to say that mental ray isn't the culprit but I'm not ready to give up yet.
Yesterday I identified some bad frames in my animation. Out of 2100 frames (4501-6600), 44 were bad. I set up backburner to re render these frames. The first one was 4624. This frame came out good, but the next 33 frames did not. Then the next ten rendered correctly. In all of the bad frames, the forest objects were clipped as if the camera was still positioned at the first frame (4624). To verify this, I moved the time slider to one of the bad frames (5209) and then changed to perspective view. Then I moved the slider back until the forest objects were clipped in a way that matched the bad frame. I happed to be frame 4624.

So, in this example forest pro interpreted the camera as being stationary even though it was moving. Then, after 33 frames, it corrected itself. What do you think? Is this forest pro or mental ray?

Kai

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Re: Forest rendering error
« Reply #10 on: September 09, 2016, 04:14:03 PM »
Here is a sequence of some of the frames that show the forest objects being clipped as if the camera was stationary at frame 4624

iToo

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Re: Forest rendering error
« Reply #11 on: September 09, 2016, 05:14:22 PM »
No, that doesn't look as typical problems we find with Mental Ray.  In fact, i don't remember a similar case with other renderers either.

Please, can you check if those frames were rendered by a specifical render node ?
Carlos Quintero
iToo Software

Kai

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Re: Forest rendering error
« Reply #12 on: September 09, 2016, 05:37:37 PM »
The highlighted frames rendered correctly. The first frame (4624) was rendered by a node using stand alone backburner. All other nodes are using the backburner service.  I see now that the next good frame (5777) is actually the second frame by that node. This is interesting but not the case in other renderings. I've been getting bad frames throughout the animations, not just on the first frames.

iToo

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Re: Forest rendering error
« Reply #13 on: September 12, 2016, 10:39:19 AM »
Please, try to render the attached scene in your render farm.
It's a simple test using Camera Clipping. It may help to check if there is some problem with clipping and Backburner, or error happens only in complex scenes.

Thanks,
Carlos Quintero
iToo Software

NCViz

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Re: Forest rendering error
« Reply #14 on: September 12, 2016, 09:20:10 PM »
While I recently posted about trees being clipped in random frames my issue more often is no trees in random frames.  I'm guessing both could be the same issue just with certain camera angles resulting in all trees in view being clipped.

Last week I set up a simple test file and was closely watching frames as they were rendered.  I noticed a repeatable pattern for the first time.  Any time a node would come online the first frame would have no trees.  Anytime I would stop and start the Backburner service on a node the first frame rendered would result in no trees.  Any frames after that would be fine.  Attached is an excerpt from the log file showing one bad frame and one good.

I also witnessed another problem.  I deleted the bad frames, set the render job to skip existing and restarted the job.  Still no trees.  I then deleted the frames again along with some extra frames.  They all rendered with no trees.