By Mark Withers (Mark) (195.99.125.204) on Wednesday, June 13, 2001 - 01:19 am:

Dear All,
there have been a significant number of threads criticising LW and its use of memory on the Mac. I'd like to add my experince.

Most of the solutions for large renders seem to revolve around doing part renders using the limited region technique. Has any one else noticed that doing this, especially in radiosity renders, yields results that are different in brightness so that you have to adjust them before you can stitch them back together: why is this?!!

OSX LW has been citicised for longer render times, but I have to say that increasingly I am turning to LW for OSX to get renders to actually complete, having built them under OS 9.1. I too allocate 750 MB to layout and it still falls over with no warning half way through renders. Lets not be too hasty in condemning the OSX version of LW6.5!

If you have been, thanks for listening.
Mark.

By ingo (62.180.158.84) on Wednesday, June 13, 2001 - 02:02 am:

Hi Mark,

LW memory management is the same on every platform, i gave my project that cant be rendered in normla resolutions under Mac OS or Mac OS X to someone who uses LW on Windows.

And there is the same problem, LW needs more than 2GB of memory for just rendering a 2000x1500 pixel picture. And if he hadn´t that much space on his HD, LW crashes the whole system. The same things that happen on both Mac OS´s. It seems that LW tries to get more memory although the system says not enough memory available.

Since this is a basic problem and i have to render higher resolutions LW is for me not usable in production, i can only use it for low resolution test renderings. Despite LW great features i now use EI again to render the same pictures with half the RAM requirements and resolutions up to 12000x9000. Maybe one nice day Newtek gets this fixed and LW is not only useable for rendering stamps ;-)

regards

ingo

By Seb (194.78.194.9) on Wednesday, June 13, 2001 - 09:04 am:

Hi there,

I don't know if the answers to the questions below were already given in the past but...

I use a Dual G4/500 with LW 6.5b, under OS 9.1 (clean) and I have 1GB of RAM (VM OFF).

900MB is allocated to Layout and it's the only application running (in the foreground, of course).

The problem: my scene is OK to render @ 5.500 x 5.500 pixels...

Not more...

And the real problem: I need to render that scene @ 12.000 and even 16.000 x 16.000 if possible.

So, my question is a quadruple one:

1/ is this normal ???
2/ is it real that under OS X 10.0.3 theses "memory related" problems'll dissapear (I'm waiting for my USB dongle, I need to use the iMate right now - and the final render in question is... for yesterday) ?
3/ is it real that with a Wintel machine, no problem at all for rendering @16.000, even with less than 1GB of physical RAM (and with the same "kind" of scene) ?
4/ if the aboves are true, when Newtek plan to fix that flaw under Macintosh hardware (and why they have not fixed it some big-time ago) ?

Thank you very much for any help on that subject.

Seb.

By Chuck Baker (Cbaker) (207.235.86.2) on Wednesday, June 13, 2001 - 10:18 am:

Hi, Seb!

Under OSX and with sufficient RAM and available HD space for VMem, you should be able to render all the resolutions available in LW. Yes, the virtual memory in OSX is robust enough, just as Windows VMem has been for quite some time.

NewTek did not modify Apple's OS VMem system because NewTek does not produce the OS - Apple does, and it is Apple, appropriately, who addressed this disparity in OS VMem performance between the Mac platform and the Windows platform.

By Chuck Baker (Cbaker) (207.235.86.2) on Wednesday, June 13, 2001 - 12:23 pm:

Hi, Ingo!

Yes, of course LW operates the same under both Mac and Windows OS, and the same scene will have pretty much identical RAM requirements on both systems. And yes, the larger the resolution of the final image the more RAM/VMem is required to render it. Also, yes again, of course the much deeper pipeline offered in a renderer that many class with the very best renderers available to the graphics, television and motion picture industries will require more RAM than most other renderers. On the other hand, there are features in that renderer not yet available in any other commerical renderer, from the extreme bit-depth to HDRI.

And yes, if your system was not already set up with it, you'll need OSX and some combination of RAM and HD space for VMem that totals 2 to 3 GB if you plan to work at up to 7K x 7K full image rendering - exact needs will vary with the scene requirements for texture maps, etc., but the image buffer itself would be about 1.8 GB. At 16K x 16K you've got a little over 5 times the pixels, so you may need up to 10 GB in RAM/free HD space for VMem. Whether Windows or Mac, this does require spending an extra $300 or more on RAM and HD space to get that specific use of a $2495 professional 3d production tool, if your current system drives are too full for the VMem requirements and you perhaps want more RAM as well. Also the price of OSX if you are a Mac user and do not have that version of the OS, about another $100 of expense.

Any job you tackle is going to require the right tools. Having LightWave is having one element of the toolset. The equipment completes the toolset for the particular job you want to accomplish. Your equipment needs will vary depending on what you want to do with LightWave, or your working method with the tools will vary to compensate for your equipment configuration. You either have the RAM/Vmem for print work at full buffer, or if the configuration you have will not do the full image buffer, then you can use limited region to render portions of the image, and stitch them together later in another application, or you can render at lower resolution and up the resolution in another application.

By Chuck Baker (Cbaker) (207.235.86.2) on Wednesday, June 13, 2001 - 12:27 pm:

Mark - the luminance really shouldn't vary when using limited region, as long as no lighting parameters have been changed between renders. I'll have the Tech Support staff do some tests on this to check our results; it might be useful if you could send your scene files along to tech@newtek.com.

By ingo (62.180.157.106) on Wednesday, June 13, 2001 - 02:26 pm:

Hi Chuck,

first thanks for your comments and your many "yes".

My experience with Mac OS X and LW is so far so good, but, when Lw needs more memory than the HD and the system can give LW crashes the system, instead of giving a "not enough memory" warning like under the classic Mac OS. Isn´t it possible to do the same precalculation like LW does under Mac OS 9 ?

And it would be nice if someone can explain how LW uses the physical and virtual memory. If i have 768 MB and LW uses only half of it seems to make no sense, or ?

regards

By Arnie (65.160.186.199) on Wednesday, June 13, 2001 - 03:24 pm:

There is no "pre-calculation" of memory requirements. The "not enough memory" message will occur when an attempt at allocating memory fails. On systems with VM, malloc() doesn't fail until the situation is dire indeed. In this case, there is some likelihood that the system will not have enough memory (real or virtual) to even put up a message and back away slowly. This can happen on any platform, it just happens faster without VM to fall back on. When the memory is extremely low, the system is really on the brink of disaster, and anything could push it over. If allocating 200MB fails because there is only 150mb available, things can behave. If it fails because there are only 2kb available, watch out. None of this behavior is LW specific or OS/HW specific.

By ingo (62.180.158.146) on Thursday, June 14, 2001 - 02:50 am:

Thanks for the explanation Arnie, that helps a lot to understand the memory management.
Can you explain why LW under Mac OS X uses not as much physical memory as possible, for some projects it uses less than half the existing memory, on other projects around two third. Isn´t the physical and virtual memory handled as one big chunk of memory ?

TIA

ingo

By Seb (194.78.194.9) on Thursday, June 14, 2001 - 06:15 am:

Hi Chuck,

Thanks for your quick reply. In fact, I knew that Mac OS "Classic" VM management was very poor but... crappy like that ! I must said that I'm a little surprised: Photoshop 6, FCP 2 and others like that does'nt exhibit theses problems, even on very large files... Indeed, not the same stuff at all, but...

Anyway, now I know that the one culprit in my case is OS 9.1, not LW 6.5b. And that's very (very) good news since, finally, I'll not receive my USB dongle in a week but rather on Saturday (thank you FedEX) ! And so, bye-bye OS 9.0 for "real" LW projects ! :-)

As soon as this first "big" project is completed, I'll post the maximum image size obtained under X (16.000 x 16.000 ? ), rendering speed and all the details of the 3 scenes in question on this forum.

Thanks for your help,

Seb.

By Arnie (204.248.132.231) on Thursday, June 14, 2001 - 11:10 am:

I have no idea why OSX would appear to leave RAM unused. The system should manage all that transparently, and it works in mysterious ways. Keeping a little as a hedge against calamity seems reasonable, but would that really show up as free? If so, would it really be available?
From long experience, I tend to be somewhat skeptical of the results from RAM meters, or CPU clock utilities for that matter. They tend to have an impact on the thing they are supposedly measuring, like in quantum mechanics.