huge model-need advice, help!

[dpcaltdcah]

We're working on a project in our office that is bigger than anything we've done before. The architects are modeling it in Revit then exporting as dwg (we aren't getting materials correctly with .fbx format) and then I import or file link into max, material with vray materials, and render. It's three 200+ story condo towers plus a huge podium level that spans the whole site and from Revit that's giving me tons and tons of objects.

 

Anwyay, I've already split the model into two parts and am rendering them separately and then putting them back together in after effects and I've turned down the irradiance map settings as low as I know how but I'm still crashing during rendering and during irradiance map rendering which of course is resulting in splotchy animations. ( the error messages are all "unexpected exceptions" )

 

any ideas on how to improve this process? I've already re-modeled all three towers in max to reduce the amount of geometry but just don't have time to remodel the base too.

any suggestions at all would be greatly appreciated!

[Tommy Burns]

Have you tried xrefs?

[foxlee]

I think I have had luck before remodelling parts and then exporting rest of revit parts like the podium to 3ds and re-importing into another file or something. This shrunk the file from 280 megs to something like 30 or so.Wish I could remember what I did, In that case I think the building was white so materials was no problem.

[REDVERTEX]

Please give the exact version of your Vray render ?

Then give us the Windows version, and MAX version. This information is very importat. We have great experience with huge files, whole cities or skyscrapers.

 

Give me this software information and then we'll see. It might be of Vray version, OS, and MAX version, 32-bit or 64-bit ....

 

We are renderiong animations with more than 20 000 000 poligons !!! And we do not have problems.

[dpcaltdcah]

foxlee, not sure I understand what you're saying I should try...

 

red vertex, I have Vray 1.50 SP2, Max Design 2009 with Service Pack 1 (32 bit) and Windows XP Professional with service pack 2 on a Dell with 4G of Ram that is literally brand new. we got 4 of this machine about three weeks ago...and it does have the 3G switch on.

 

also yes to xrefs.

[Tommy L]

Hello Cassie,

+200 storeys? wow, thats big. Are the towers repetitive? I dont think putting them together in AE is going to be your solution. Proxy-ing each story would be a help if they are identical, then x-ref the whole tower into a different file 3 times. Are you guys using 64bit? Could be worth buying xp64 for a the workstations. Say hi to Dan for me

[Vince Paske]

Have you tried using VRay proxies for any of the geometry? Make a copy of the items you do proxy as there's no way to reverse the proxy back to it's original geometry.

This may be a good time to switch to an all 64-bit setup, although your IT department would just love that request.

[whitetr]

Are you using X-Refs for anything?

Are the splotches on a single frame or animation? What resolution?

How big are your renders?

What's your render settings at?

Poly count? How many maps? How big are the maps?

Has the imported geometry from Revit been fixed?

There are so many factors that can and will affect your renders/scene. Just the fact that it's a big scene doesn't say much. We work daily with very large scenes with lots of geometry and maps. We do run on 64 bit though...which may be the key. Post up some specifics and we'll try to work through it all:)

Edited August 25, 2008 by whitetr
spelling

[dpcaltdcah]

yeah I'm lobbying for a 64 bit to run irradiance maps on (we don't have an IT department--one of the design partners does the IT on the side--it's a terrible setup ;-)

 

all of the trees and plants are vray proxies. since the building geometry itself comes from Revit, would that work? weird things happen when I try to modify revit geometry...

 

Hi tom! I meant +100 stories but still, it's big. The towers themselves I've remodeled myself so they're actually not very big. and no they're not exactly the same. but maybe I'll proxy them anyway. it's the podium level which keeps changing that's the huge part. I've reimported that thing from revit like 20 times. and of course around here it's always, 'add more trees, add more trees' ;-) currently this animation is already in six layers. I spent 7 hours just putting things in the queue last week.

[dpcaltdcah]

the Revit stuff is xrefed into a main file which has the lights/cameras and some matte context stuff. the splotches are in the animations only. the animation frames are 800 x 450 . I haven't done anything to the imported revit geometry besides apply vray materials to it and the occasional auto smooth. it's still being designed so we keep re-importing it as things change. we've tried dwg file link, and import and .fbx

 

render settings - I'll post some screen captures.

 

poly count - 8 million for podium level alone. 3 mill in context. max towers are only 300,000

[BrianKitts]

with the problem that you are facing, xrefs won't provide a solution. You are crashing because your system is running out of memory at rendertime. Regardless of if the geometry is in the file or xref'd into a file all that data has to be compiled on your system when you hit the render button.

 

The only solutions that could give you any help would be to proxy as much geometry as possible and to render to a vrimg file. Also you mentioned getting a 64bit machine for calculating your irradiance map..... if it takes a 64bit machine with more RAM to calculate the irr.... most likely it will take that same machine to be able to render the scene. Again this gets back to having to load all the geometry to render.

 

The majority of our work is done with huge models out of Archicad which like Revit isn't exactly effiecient when it comes to that mass amounts of geometry that it creates. For us we pushed it as far as we could go in 32bit, but with how much information is going into the BIM models these days the extra RAM is necessary to be able to render these models without spending alot of time optimizing and cleaning up your imported geometry.

[whitetr]

Wow. The podium sounds like it's a monster:)

Take a look at the geometry. Messy geometry can really confuse VRay. Your context sounds on par at 3M. You shouldn't have issues if that's proxied stuff. The podium is really sound like the killer though.

Out of curiosity (and it looks like this), you are doing an IR prepass, right? If so, be sure to uncheck "don't render final image" in the global switches. An IR pre-pass would go very quickly. Also, there would not be a need to render every frame for a prepass...do every 5 or 10 frames depending on your animation needs. But you shouldn'e need every frame for you prepass.

Edited August 25, 2008 by whitetr
spelling...again...cuz i'm an idiot:)

[Vince Paske]

Here's a link to a previous discussion that may help you out:

 

http://www.cgarchitect.com/vb/31962-max-runs-out-ram-crashes.html

[Tommy L]

Does it render with glossies turned off in the global panel?

[dpcaltdcah]

you guys are being so helpful, thanks.

 

glossy off still crashes.

 

yes to IR prepass--I do every 10 frames. but uncheck 'don't render final image' ? wouldn't that make it slower?

 

I know it's a memory issue but they literally just bought four new machines because we couldn't render the project before this one. (and I thought THAT was big ;-) I could maybe talk them into one 64 bit machine but there's NO way I'm getting more than that. I suspect that in the end I'll end up re-modeling this in max. when I did the towers I reduced the number of objects by like 95 % and then there wasn't any weird geometry left because it was all max. They're just hoping I can avoid spending like a week doing that...

 

Brian, what is a vrimg file?

[Tommy L]

Well, 64bit is the way forward, no doubt. But if its not available, you'll have to make do.

I think with this one you'll have to strip it back to nothing and put back the detail peice by peice in order of preference....

Try rendering with default lights (no GI) and with a mat override on with a default vray grey material. Once you get that to work, try it with default lighting and mat override disabled.

When that wokrks,. you cn start figuring out your lighting.

One thing to consider would be faking the GI.

Another would be to use LWF as this actually makes the lighting computations less complex.

[dpcaltdcah]

but tom, you know that in this office we have to have the highest level of extreme detail all the time, everywhere, and all parts are super important, even the back alley and loading dock! ;-) I will try default lights/matter override but I'm already faking GI--after waukegan the projects have just gotten bigger and bigger and I haven't been able to use a second bounce since then. lots of fill lights, that's all. you know how awesome most of the computers on our nework are... ;-)

 

I just read somewhere else to try changing default geometry in the raycaster parameters in the vray system settings from static to dynamic. anyone know what this does? doing that and increasing the minimum leaf size seems to be helping...

[Tommy L]

if you get your head around LWF then you can eliminate the fill lights. That will help your cause immensely. Also, for externals, I would recommend you dont use a second bounce anyway. What color mapping are you using?

Try this:

GI primary irr map

Color mapping exponential (tick all boxes to the right)

Vray Camera on default settings.

Vray Sun on default settings (create sky on prompt). Lift the sun to apropriate angle.

 

THEN: render without geometry, adjust exposure on the camera til the sky looks about right.

 

Then if your shadows are to dark, play with exposure settings in the color mapping. You shouldnt need any fill lights.

 

Edit: you could also try doing an .fbx import from RTevit. You'll lose all the gropup headers which are such a headache in max and swell the file-size.

Edited August 25, 2008 by Tommy L

[dpcaltdcah]

I might try LWF again with the next project, but dan wasn't happy with how it was looking when you left--I think you were still learning about it then. and now that it's just me I don't have time to try a lot of new things. but I agree it's promising. I'll try your other suggestions, thanks!

 

we tried fbx but you know how we import then select by revit material then re-material with vray? fbx wasn't bringing in all the revit materials. we suspect it's because in the original revit file they hadn't been using 'promaterials' but haven't had a chance to test that theory. the file's so big at this point, I really need to be able to see those revit materials to know what's what. and they don't have time to change it on their end.

[Tommy L]

Dans an assh*ole and he doesnt know sh*t.

Good luck.

[dpcaltdcah]

thanks for your suggestions, tom. I appreciate it a lot.

Ryan and I are thinking we'll try lwf again for sure with the next project, I'll let you know how it goes.

;-)

[dpcaltdcah]

so changing that setting from static to dynamic in the raycaster parameters worked and now it's totally rendering...anyone know what that does?

[Tommy L]

........

Default geometry - internally V-Ray maintains four raycasting engines. All of them are built around the idea of a BSP tree, but have different uses. The engines can be grouped into raycasters for non-motion blurred and for motion blurred geometry, as well as for static and dynamic geometry. This parameter determines the type of geometry for standard 3ds Max mesh objects. Note that some objects (displacement-mapped objects, VRayProxy and VRayFur objects, for example) always generate dynamic geometry, regardless of this setting.

 

 

 

Static - all geometry is precompiled into an acceleration structure at the beginning of the rendering and remains there until the end of the frame. The static raycasters are not limited in any way and will consume as much memory as necessary.

 

 

 

Dynamic - geometry is loaded and unloaded on the fly depending on which part of the scene is being rendered. The total memory taken up by the dynamic raycasters can be controlled by the Dynamic memory limit parameter.

 

 

 

Auto - some objects are compiled as static geometry, while others as dynamic. V-Ray makes the decision on which type to use based on the face count for an object and the number of its instances in the scene.

 

 

 

Dynamic memory limit - the total RAM limit for the dynamic raycasters. Note that the memory pool is shared between the different rendering threads. Therefore, if geometry needs to be unloaded and loaded too often, the threads must wait for each other and the rendering performance will suffer.

[dpcaltdcah]

you're the best, thanks.

that makes total sense.

[REDVERTEX]

Dynamic setting are totally slower than static! It works but its very slow. Especially if you rendering sets of animation.

You have the hardware. You need the right software

WinXPx64 !!! 3DSmax x64 !!!

This is the only safe choice for huge scenes

 

good luck