AVI walkthrough memory problems Revit 6.1?

[bobo]

I have a model comprised of several revit files. I have activated a section box to limit the model to only a relatively small size, and yet the render avi still stops working after only a few frames. I have a P4 3.2 with 2GB ram and a top line graphics card, large harddisk...why is this happening. I have limited several settings, but it keeps on happening.

Someone mentioned the other day that the largest file size on export AVI's is now only 1000x1000 pixels, whilst before it was much larger. Was this reduced for memory issues, is it possible there is a problem with large files on Revit 6.1. Still imgaes are fine, but AVI's don't seem to render as they did in earlier versions.

Any ideas...how to limit model size, problems, work-arounds?..anyone!

[bobo]

In addition, the AVI frames tend to render painfully slow for a relatively small 1000x1000 pixel image....is it possible the section box does not work effectively in Revit 6.1? This would explain the crashing and the slow render times for each frame.

[bobo]

It is interesting to note that I deleted the attached models that are outside of the section box area being rendered in the AVI walkthrough and their has been no memory problems since...is this not what the section box is for?...more weight to my feeling the section box is not doing what it is intended to do, that is, limit the amount of objects to be rendered. Surely the Revit developers need to address this ASAP if it is indeed the case. Has anyone else had a similar experience?

[bobo]

Well, following on from my personal quest here, it seems I spoke to soon, it eventually stopped rendering again! It seems odd to run out of memory though on a file size that rendered perfectly well on the same machine in version 6.0. In that instance the final AVI size was over 878mb, the current AVI render stops at approx 34mb every time with a memory shortage.

Once again, any ideas or comments appreciated. I am getting quietly desperate as to how I am to output the AVI I have spent considerable time compiling. sigh...

[christopher.zoog51272]

hmmm... ok I have a similar machine, but i haven't done any heavy walkthroughs at that high of a resolution yet, but I have done a few at standards resolutions.

I guess my first though would be to change your resolution.

I am curious about the 1000x1000 size......What is the end goal of you presentation, will it be displayed on tv's or just computer screens, will it be projected, etc?

I typically render out to 640x480 (a square pixel representation of NTSC-DV standard of 720x480 interlaced) at 30 fps (it really should be 29.97 fps, but I can't do that in revit) or just 720x480. If your country uses PAL it's 720x576 @ 25 fps (non-square)

640i (640x480) is NTSC broadcast standard.

I use Sony Pictures Digital’s Vegas 4.0 (soon to be 5.0) as my NLE to put the animations together. (DV editing and DVD authoring is a hobby of mine) By rendering to a standard NTSC res, I find it easier to mix them with DV footage or still photos., etc

Just an FYI.... Lately I have been doing more "history channel documentary" style pans and gentle zooms on still renders to created the effect of motion. It's really quite effective, and they render in a fraction of the time. Were also considering moving to Viz2005 for animation work as the ar3 render times are killing us.

Sorry I can’t be of more help, try a lower res to see if it works.

[Steve_Stafford]

Just an FYI.... Lately I have been doing more "history channel documentary" style pans and gentle zooms on still renders to created the effect of motion...

I've been advocating this approach as well...it's a heck of alot more manageable from the perspective of hardware and time.

[bobo]

Well, thanks for your interest in my dillemma. I guess firstly I should address your point on the resolution..

The actual rendering is not set to any particuar video format at this stage as it is a trial run (clearly not successful). However your point is well taken in that it might be worth adjusting the overall output size to suit a standard screen.

However, even as it is currently set, at about 1138x892 pixels, isn't this only 125dpi? Hardly ground breaking resolution. Is not a standard screen resolution on a computer 1024x768 pixels (yet alone a TV screen)? Ideally I would like to send the image to a TV via a DVD, but surely that would require way higher specs for a full sized reproduction at resonable quality. A pic at 640x480 as you suggest will surely be only able to be played at minimal resolution on a computer screen (well at least without looking overly devoid of much of the larger scale detail)?

Any comments appreciated! :)

[GuyR]

I've done a fair bit of AVI's with AR .
I've also had this happen. I haven't worked out the problem. Recently the same model worked on a 1.3Ghz 768MB but didn't on my P4 3.06Ghz 1GB laptop. And worse than this rendering time for each frame on the P4 was 80sec. On the 1.3Ghz 90sec. Not that much slower!!!!

Regarding resolution I've found I get significantly better viewing on a TV if I render to as high a resolution as possible (keeping the aspect ratio correct) and then generate a 720x576 MPEG2 from that. The downside is time to render and increased time to encode. I don't normally do this until the model is getting more complete.

I don't bother with the fact PC screens are much higher resolution. If you are writing to DVD you are either using DVD+ or DVD-. I have all sorts of problems sorting out clients trying to run the DVD's on their PC's. Most PC drives can read either + or - but not both unless the PC is very recent. Whereas settop DVD players are far most tolerant. I just tell them to sit down in front of the TV. Much more comfortable viewing as well :-)

The reality is for serious movie generation you need massive hardware or lots of time. I usually work on how much I can render per night and only render that many frames. Then patch together all the AVI's in the video editor.
For firms with say 10+ revit licenses (and therefore good hardware) a network capable rendering solution will be very productive.

It's also worth keeping an eye on nVidia and their realtime hardware they're coming out with now. This will be very exciting if it works as they are saying.

Guy

[PeterJ]

It's also worth keeping an eye on nVidia and their realtime hardware they're coming out with now. This will be very exciting if it works as they are saying.Guy

And if Revit makes use of the video cards capabilities!


DV editing and DVD authoring is a hobby of mine

Let me guess, Noah is quite the movie star already?

[bobo]

Guy, I noticed you had said you had similiar problems with memory issues with rendering, did you find a fix?.. It has been suggested that my machine specs are more than adequate and revit settings reasonable, then perhaps is it related to the cache or page file sizes?...does anyone have any background in this area and whether this might be a related issue that could be affecting rendering?.... Of interest though i can relate to guy's comments about rendering times, they seem suddenly extra ordinarily long for some reason, when before i was getting the same reuslt in much less time... only significant changes i can think of.... update to Revit 6.1 from 6, and using linked files now instead of one large single file.. sigh..still unable to output AVI... at least only up to about 15 frames before memory issue.

As for recommendations on using DVD and TV, thanks and I will keep advice handy if and when I get my AVI out!.

[beegee]

Rietveld and GuyR, have you seen This Topic ? (www.zoogdesign.com/forums/phpBB2/viewtopic.php?t=3574&highlight=)

You may wish to get involved.

[PeterJ]

yuo could also take a look at Bink (http://www.radgametools.com) which I think Kroke has used to tweak small frame output into larger scale output with little appreciable loss in quality. It's a free download.

[Chris Riddle]

We have been battling this memory problem big time.
It's a 6.1 problem that didn't exist in 6.0. In our experience, it happens irrespective of the memory specs of the computer it happens to be on. According to Revit in Waltham, it's related to Accu-render trees. They refer to it as a 'memory leak'. We find that you can do between 10 and 30 frames before it crashes with a low memory message. The only workaround we've found is to do the walkthrough in batches of 20 or so frames, and reassemble them with Microsoft Moviemaker into a continuous walkthrough. This is immensely time consuming, plus you lose resolution with Moviemaker. We try to commandeer four or five computers and have them all running pieces of the walkthrough. Obviously you have to do this after-hours when the normal users aren't around. And it takes more or less full time attention.

This is a serious problem which essentially makes outdoor walkthroughs unfeasible economically. Revit says they are working on it and that the problem may be with Accu-render, not Revit. (I said I don't care whose problem it is.)

Chris Riddle

[GuyR]

This is a serious problem which essentially makes outdoor walkthroughs unfeasible economically. Revit says they are working on it and that the problem may be with Accu-render, not Revit. (I said I don't care whose problem it is.)

It does seem like a memory leak. But I've had no problems rendering on the Athlon compared to the P4, and the athlon's got LESS memory. I don't know if that's got something to do with it. I've had the problem in projects without trees. I've got a 3000 frame model rendering at the moment with trees so I'll see what happens with that.

If you want to be doing this seriously I'd be living with dwg exporting and importing into an industrial strength rendering solution, particularly if you can network render.

I don't know why you would lose resolution with Moviemaker. I'd invest in a decent videoeditor if I was you. The cheapest way to get MediaStudio Pro or Premiere is to buy a DV editing solution which includes this software. And if you get a realtime solution it's much quicker editing. People like http://www.videoguys.com/ do good deals on DVD writers + editing solutions etc.


Rietveld and GuyR, have you seen This Topic ?

Guy, I noticed you had said you had similiar problems with memory issues with rendering, did you find a fix?

For me moving rendering to the Athlon fixed the problem, so far...

To be honest I'm not interested in spending time sorting this out unless it becomes a show stopper for me, because as far as I'm concerned Accurender will be replaced sometime in the future.
Autodesk has made it clear by past actions that they don't want to be paying 3rd parties for software solutions as good as they might be.

So with the future uncertainty of Accurender I'm reluctant to invest significant time getting further into it's quirks.

Guy

[bobo]

Refer This Post (www.zoogdesign.com/forums/phpBB2/viewtopic.php?t=3770&highlight=)

[fernando]

why did u don't render to JPG insted to AVI ?
i use to do this and i'm happy this way
do the walktrhu render as usual, but choose to save to jpg
it will render X jpg's of mi film wich i late drop to some kind of software to create a film
it's is much litter
if it crash i could continue from the last picture rendered
and also i could drop the rendering trow other's machines in my office :wink:
to my, it work's 5 star's