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Vray Multiscatter issues


Alyosha
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Hello,

 

 

Hopefully someone can help me with this nutcracker I've been on for the past day, the official forums of the product have been VERY UN-helpful so far.

 

I've been having this silly crash problem with multiscatter, most often it simply crashes a bit into the start of the render - while other times it renders normally, and all that without changing any settings whatsoever.

 

Needless to say, normal work is impossible.

 

Wierdest thing is i have the latest version which is supposed to work with 2011 64 bit max.

 

Also it crashes max all together when i go to menu - file - choose stuff like save or import it just crashes it all down o.O.o?

 

And the price tag on the thing is like for a pro plugin, so i must admit i'm pretty pissed at the moment.

 

It does seem to be connected with adding various meshes to the mix rather than with just the number of instances of a particular mesh - seems to work good if i only have one kind of a mesh on the surface, but if i have various meshes it will collapse like 5 seconds into the render when it starts doing the light cache (tho it crashed with other types of secondary bounces as well so i guess it's not related) even if there's only a handful of instances in the scene.

 

If anyone could share some insight into this matter it might prove helpful:-)

 

 

*Edit it definitly is related to adding multiple kinds of proxy objects to the scene, i.e. tree1, tree2...with only one it works perfectly, if i add additional i keeps getting more and more unstable, no matter the number of actual instances, can be as little as a dussen or smtn.

Edited by Alyosha
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  • 3 weeks later...

Hi Alyosha

 

Did you find the solution to your render problems?

 

I've not had any issues with my multiscatter as far as number of scatter meshes is concerned. I'm currently rendering an area with a max of 10000000 trees over a 6km wide area. Max 2011 64bit, win 7.

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Hey

 

No, not really, but instead I used a different model set and it works much better, but hardly to say without issues.

 

I pick the models from the scene and it somehow creates hundreds of instances and places them under hidden objects, i guess to pull it from there when needed, but the worst thing is it often unloads like 30 at a time into a scene for no aparent reason, and no instances either, simply makes 30 copies of each of the individual objects and drops them on top of original objects so i have to delete them manually each time it does that.

 

Can't say i'm thrilled by the performance of this plug.

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yeah i have like 5 tree objects in scene and for some odd reason when i pick em up with mscatter it will randomly create cca 30 copies of each object (could be instances as well but in any case it displays them as full poly, not as box), and drop them on the same spot. Needless to say viewport performance drops to 10% or smtn so i have to delete em all.

 

Couldnt really figure out when or why it happens, maybe when a render is initialized with ms on or when i turn ms on/off.

 

other than that it works pretty well with different tree objects than the ones i used originally, which would just crash it.

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Weird, I've never experienced it myself. The closest thing I've had is multiscatters preview mode set to points instead of box or pyramid, which with a lot of objects can slow things down.

 

Did you try clearing all other objects out of the scene and trying with some basic boxes and one instance of MS? (i realise you probably moved on from this project now)

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Actually i havent moved on yet but it's in it's final stages and i'm not touching multiscatter settings again until the final renders are out:-)

 

-The thing is it does random wierd stuff, i am not even sure how to approach troubleshooting here, i guess i'll just use it and learn from experience.

 

For example first attempt crashed during render time, then i changed tree objects used different models it worked, but it started occassionaly doing the above mentioned thing...

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I have it set to 4 gb, and i've tried different settings with that as well, even pumped it up to 8 but it didnt made any difference if you're referring to the problem described in my initial post in this threat. Tested a bunch of settings, too, nothing seemed to make any difference.

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  • 1 year later...

Hey, just wondering if you ever found out any more about this... The studio I'm working at seems to be having some of the same issues, and it seems to only happen when there is a multiscatter present. The big issue is random crashes upon saving a scene, or even opening up the file pull down menu. It also seems to be only happening on windows 7 machines, not xp. We are using 2010 Design, Vray 1.5 sp5 and the latest multiscatter.

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Actually I've gained some experience with multiscatter since then...as far as I've gathered by now, two things are important with multiscatter that may cause it to crash - the type of model you use as an instancing model and the sheer number of instances that may cause RAM problems.

 

Using very complex models like evermotion trees or somesuch in thousands or even only in hundreds has caused my mscatter to crash repeatedly, replacing them with models like "itrees" and "igrass" worked perfectly, supposedly those models are somehow optimized for use with multiscatter. I'm not sure why it sometimes (in my case often) crashes with your normal models though.

 

Second issue can be sheer number of objects used by multiscatter, despite the marketing, multiscatter doesnt allow you to go into gazillions of instances completely unpunished. Specially in complex scenes where other objects may already burden your RAM, it can very easily cause a crash during the render itself (usually during LC calculation), so try looking into that as well.

 

Anyway, those are just my observations up to date, hope it helps.

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it might be a problematic, hell it can be even the "normal map" bug of multiscatter that still exists through 5 updates..

 

check your msccattered objects, one or two should have a "normal map" in one of the map slots, this makes it crash on render start...

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I ran into the normal map problem early on a couple weeks ago and fixed that. I didn't know it was a known issue or a common one, but now I do! Its definitely not a memory problem at all. Working on a system with 32gb, and the crashes do not occur when rendering. Its usually when doing normal things like saving, or file pulldown menu. It could be a rpmanager issue, or multiscatter, not sure. It also seems like files crash more on windows 7 systems more than xp at the studio I've been working at. This is a really tough one to troubleshoot.

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  • 3 months later...

hi

even i am facing the same problem with multi scatter... before i had no problems with it. but now it crashes and after several attempts it renders and when i change the camera angle and render again crashes...while calcualting light cache...

As alyosha said it might be crashing by using evermotion models for scatter...boz before i used to use only itrees and igrass and i had no problems....recently i use evermotion model and problem started...but now i deleted that model and using igrass model but still its crashing...

strange thing is when i open old project files where i had used multiscatter before and render...it renders fine...only recent files have problems.....

plz someone had found the solution plz share.....

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  • 3 weeks later...

Hello, Alyosha.

 

Must say I've never posted, but think I know what's going on. After hours spent, I realized that one should NEVER make a group with a multiscatter object in it. It makes a bunch of hidden duplicates and the scene starts crashing. Hope it helps.

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I forgot to share something else. I found this thread 'cause I had max crashing with multiscatter... Turned out you should not use multiscatter with photometric lights with IES files. Use the vray IES light instead. At least solved my problem. Hope it helps with other cases...

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  • 3 months later...

Hi!! i have same problem,but I found it what is the problem.I have Xeon workstation 24 gb ram.when you use only one multiscatter,max will not be crash but when you add second multiscatter max will be crash,try use only one multiscatter in the scene.sorry for bad english.

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  • 1 month later...

Hi, I'm rendering a scene with multiscatter, some iGrass models, and a fairly uncomplicated building. My render time shoots through the roof when I turn the grass on, the light cache estimate is 80 hours!!! When I hide the grass it renders in about 1 hour... Everything I've read about multiscatter says it allows fast render time, what's wrong with my scene?

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Hey, in this case I'd say it's probably your ram. First check the dynamic memory limit - under vray settings tab check the dynamic memory limit assignment. If you have, say, 8 gigs of ram available all together you can probably set it up to around 5 GB.

 

Also make sure you don't have instance overkill for the grass...do a test or two and see which number is still fine to get you what you need. This is specially important if you don't have that much ram available on your machine.

 

And in the end; even though MScatter does allow incomparibly greater number of instances to cover a given area and render without any problems, you should know it's not omnipotent - if you want to cover a 10 square mile with 1000000000000000000000000000000000000 billion instances it will still crash your render because of the lack of available ram.

 

Testing different scatter solutions for your specific machine will give you the best knowledge of how to set up your mscatter scenes.

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