Carrara stalls mid-render
nomuse_f2f0b8cc2a
Posts: 0
Carrara 7.2 pro, macBook dual i7 running Mountain Lion. Carrara stalls at random places in a render (different spots each time I render). Can't quit the render; either aborting render or NOT aborting render (aka hitting "cancel" locks up the application for good and it has to be force-quit.
No indirect light, no AO, no displacement maps, no transparency; basically everything is unchecked on the render engine but Bump and Shaders. Sometimes Cararra goes right through without difficulty, finishing the render in a handful of seconds. Other times it stops dead, as above.
I am very displeased with this, especially as I am doing layout tweaks and if I don't save before every test render, I lose my work.
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Is this new, or has it been going on for as long as you've had Mountain Lion?
Pretty much. I hadn't done any serious renders since installing Carrara.
Tried turning off multi-threading, saving all texture maps internally. Sometimes the renders finish. Sometimes they don't. Only thing that seems to make them finish more often is turning off "Full Raytracing," shadows, and bump mapping. Very much stalls on indirect lighting. I'm going to see if I can massage the setting of that, now. Once I restart again!
I know the C8.5 beta had some fixes for Mountain Lion, hopefully someone who is using C7 with it has a better idea of what can be done.
Interesting. Tile 1 finished the image...2, 3 and 4 stopped early in the image and remained stalled. When I restart AGAAAAAIIIN I'll try changing the tile size to see if I learn more. That was with indirect light switched on...had finished three successful renders in a row without it, including using AO.
Nope. With a tile size of 64, tiles 1 and 4 stopped dead in arbitrary places. The other tiles completed the image.
With a tile size of 16, only one stalled out. Set occlusion to 10 meters, dialed photon count all the way down to 1000, went to odd dominance field rendering and completed a render successfully. Dialed back up to 5,000 photons and switched to "fast" lighting instead of "preview" (still with tile size 16 and odd dominance); all tiles stalled early into the image, in again random places.
Preview, interpolation off, 5,000 photons: render got a little further but still stalled. Since these stalls are in random places I'm tempted to just render three or four times and combine the good parts in PhotoShop!
Dialed down interpolation and photon map accuracy, still in Preview quality with 5,000 photons; stalled early in the image again.
Apparently, no tweaking of the settings is going to allow a decent render to complete.
C7 had trouble with Leopard for some of us. C8 is supported only through Snow Leopard 10.6...but the beta 8.5 does support Lion and Mountain Lion. It's entirely possible it's an unfixable problem if you're having trouble with C7 at this point.
Hrm. A little more information. The stall isn't permanent. It is another of Carrara's exponential increases in time. The difference between fast spots on the render and slow spots on the render is much larger whilst running on 10.8. My old G4 seems to do better at bearing down and grinding through on the tough spots. On 10.8, 99% of the render is done in five minutes. But as of this moment, I've waited four hours to see one of the stalled tiles finally move. Weird. Not only is this a faster CPU, I have eight times the RAM on that machine! So something about 10.8 isn't allowing it to allocate CPU resources properly...
Well, from the look of it, I should have a 1,200 x 1,000 single frame render, with most of the lighting settings down at the lowest quality setting, finished some time in the next twenty hours. Good thing I have another laptop I can continue working on while this is rendering, eh?
If your old G4 works, I would use that. C7.2 is a 32 bit application, it is not 64 bit, so anything above a theoretical 4 GBs of RAM won't make a difference. It's also an unsupported version of OS X. DAZ's website clearly states that the production build of C8 isn't compatible with your OS version. I would imagine C7.2 would be even more so. I'm not surprised Carrara is having problems.
I'm on a G5 with multiple boot drives- One is OS X 10.4.4.11 because I have found that Carrara 7.2 Pro is very stable. I use a network render node and sometimes use an Intel Core 2 Duo iMac with Snow Leopard. It works well enough for a node but not stable enough for a full Carrara install. Maybe use Carrara on the G4 to set up the scene and install a node on your other machine and see how that works for you.
I have some issues with shaders that use procedural functions like noise or other random functions, volumetric effects with any type of GI and sometimes trees. The issues are differences in the gamma of the render buckets and for the shaders and trees differences in how the leaves and random shader functions are calculated between the PPC machines on the network and the intel iMac.
I'm actually on the reverse of that; set up the scene in 10.8 and transferred to the 10.4 machine to render. My experience with C 7.2 has not been the same. I don't do a lot of rendering in it so I can't speak to stability -- rarely had a problem I remember. But mesh modeling, I have frequent lock-ups. 10.8 has been no better and no worse for working in mesh. Hint to the wise -- spend as little time in the UV editor as humanly possible. And save often...every ten keystrokes, in the UV mapper.
Both machines are rendering the same file right now and they are showing about the same patterns. So this may be a peculiarity in the scene -- I've almost never rendered using the "large" scene default, or with a custom sky dome. As of this moment the Intel machine is ahead by a good margin. I expect it to finish some time before tomorrow morning.
In the meantime I'm using a THIRD machine to clean up a UV map.
Yup. RAM was the clue. The sudden brick-wall in render times is Carrara running out of addressable RAM. I left the computer alone for the evening and, as I had hoped, it eventually ground its way through the render. Follow-up renders (with Indirect turned off) were zippy-fast.
Not sure if you're aware of these, but there are some things that you can do to lighten the load:
Since you're using render nodes, you're obviously rendering through the Batch Queue, so if you hit a spot where you're having issues, you can pause the render (even on a still frame) and quit Carrara, relaunch it and continue the render from the point where it left off.
You can go to Carrara's preferences and turn down the texture spooling as low as you can (but not off).
You can go to the Edit Menu and consolidate duplicate textures and delete unused textures.
Don't save your scene internally. I use content like V4 fairly often and have found that saving locally reduces file sizes and the host computer transfers all the files over to the nodes. The exception would be custom leaves and plugins. Those need to be installed on the nodes even if a scene is saved internally.
I noticed that heavy use of multiple alpha maps in the same calculation area can help to stall a core pretty good. I'm constantly trying to create modeled solutions that don't require alpha mapping. Hair is particularly nasty - some products worse than others. I bought a cool new hairstyle last year that I never use, simple because of it's immense need to put a halt to my fast cpu cores. It does help some to bring the tile size of the render settings down to 16, which has the benefit of putting more cores on that slow spot, rather than stalling one or two for the entire duration of the frame.
I'm seeing this issue now on a Mac running OS X 10.12.1; in the middle of a very long and large render, I have four out of eight blocks (my machine has 4 dual-threaded cores) that are no longer making progress, while the others are still zipping along quite nicely. The complexity of the areas that are being rendered successfully, and the ones that are not being rendered at all is equivalent: it's not that those particular threads are hung up on some particularly complex calculation.
When other people have seen this, does Carrara eventually recover and start processing those hung blocks again? In other words, if I wait patiently, will it continue rendering? Or when something stalls, does it stall forever?
I would get that occasionally if I repeatedly re-render. Seemed to happen mainly on my Macbook Pro, so maybe it's temperature related? There was no logic or consistency to the place where it stalled. Haven't seen it now for many months (partly because I sold my Macbook Pro!)
I presume that bucket is stalled forever - I left it running for 24 hours once and it didn't pick up.
Weirdly, of four stalled buckets, two suddenly picked up and finished, one started up and then stalled again, and three completed their tasks, began new tasks, and then stalled. So I now have five stalled buckets, but only two are the same buckets as when I wrote my first message.
I'm going to leave the render running for now and see if any of the five zombies miraculously come back to life.