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3DeeNut
07-21-2006, 01:55 PM
Is there a limit for the maximum pixel limit? I have an image that admittedly is kinda large (36in x 72in), but ive got 2.0 gigs of memory and i can reneder the image with ease if i lower the pixel (height). But for some reason, when i up the resolution to (10,800 x 5400) ([email protected] size)) a message instantly appears that says "image creation failed" and all i can do is abort. If anyone has any suggestions I would really appreciate it. The model is relatively simple when compared to some of the models i render i cant see why its being a problem.

Other factors which may help to know
1. No reflections (ray trace reflections are off)
2. No Caustics
3. No Radiosity

My system (at work) is a dual 2.0ghz G5 with 2 gigs memory.

Celshader
07-21-2006, 02:00 PM
Have you tried lowering your Segment Memory to break the image up into smaller, less-memory-intensive sections?

Years ago, I once had to render a 6K image on a computer with 1GB of memory. I had to lower the Segment Memory to 1MB for that one image. It took a little longer, but it rendered.

-+-

Also, use F10 to render the image directly to your hard drive instead of F9. If you're running low on memory, you might not have enough memory to display the image in LightWave's Image Viewer.

3DeeNut
07-21-2006, 02:13 PM
Thanks for the suggestion.
I tried the suggestion and well, it worked but only somewhat. The error is no longer the same, now it says "Not Enough Memory for Frame Buffers", but its not too big a deal. I got my boss to agree to 125dpi which brings me to 9000 x 4500. I am just gonna render at that. I get not problems at that size at all. I would love to know what these limitations really mean as very often I am required to make posters at this size. Id hate to have a critical client and this problem.

Again thats greatly for the help.

Dave Jerrard
07-21-2006, 03:38 PM
Is there a limit for the maximum pixel limit? I have an image that admittedly is kinda large (36in x 72in), First, let me stop here for a second. This actually says nothing about the image itself. For all I know, it could be a single pixel, with a really low Pixels Per Inch output ratio. Pixel dimensions are the important, and useful numbers. Inches & DPI only have any useful info when the image is actually being output onto a display or printer. You can print the same image at different sizes and each will have a differnt PPI value, but will have the exact same pixel dimensions. <rant off>




but ive got 2.0 gigs of memory and i can reneder the image with ease if i lower the pixel (height). But for some reason, when i up the resolution to (10,800 x 5400) ([email protected] size)) a message instantly appears that says "image creation failed" and all i can do is abort. If anyone has any suggestions I would really appreciate it. The model is relatively simple when compared to some of the models i render i cant see why its being a problem.

Other factors which may help to know
1. No reflections (ray trace reflections are off)
2. No Caustics
3. No Radiosity

My system (at work) is a dual 2.0ghz G5 with 2 gigs memory.LightWave uses a lot more information when it renders an image than just the standard Red, Green Blur & Alpha channels. It's creating several different buffers, ranging from 8 to 32 bits per pixel. I think it actually generates a total of 196 bits per pixel, containg stuff like raw color, shading, angular info, depth, transparency, reflections, etc.. If you look at the Render Buffer View plugin, that has a list of 19 buffers that LightWave generates.

So to create enough buffer space for an image 10800x5400, it's trying to find 1,428,840,000 bytes of meory to store it all in - 10800pixels * 5400pixels * 196 bits per pixel / 8 bits per byte. Most of this needs to be in memory all the time (if not all) because it's constantly being written to. It it wasn't, rendering would be extremely slow. On a 2GB system, this means you have just over 500 MB left to work with, and that's got to store the scene, objects and any images, as well as the LightWave code, and OS overhead. THat's not a lot of room.

If you were running with more RAM with a 64bit system, you could probably do this fine. Another option is to render the image in strips. There's some render controllers out there that will do this for you, or you can use Limited Region and do it manually. This lets you render lower resolution strip of the image that LightWave can handle, and then you combine them in something like Photoshop.

Yet another option is to render at a lower resolution that there's enough RAM for and go with a lower output PPI. What's the output destination going to be? If it's a poster, 150PPI is probably a bit high, 100 should be more than adequate. The larger the output, the lower the PPI that's needed because the viewing distance becomes greater. Billboards have PPI values of around 5 (halftone screens for these are something like 8 lines per inch, opposed to the 65 lines per inch of a typical newspaper).

If it's something like a brochure, then sharpness becomes more important, and higher PPI is needed, so you're back to the memory issues. Rendering in strips will be the easiest solution.

He Who Remembers Teaching Printers How To Do This Stuff A Decade Ago.

Triskelion
10-22-2006, 03:18 PM
Thanks Dave,
I was just scanning for the same Memory Problem. I just built a 64 bit AMD Athalon machine with 4 gig of RAM, running WinXP Pro 32bit, I just got LW 9. I was trying to render a highly detailed and complex scene "Poster" for print. My end target was 34" x 58" at 300dpi, I know LW renders at 72 dpi, so I had to calculate the pixel number to 10200 x 16000 pixels, 16,000 is LW 9's limit. This would not fly. Segment Memory was set to 100MB, I tried many variations from 1MB to 3000MB, this didn't work either. So I have tried to render at 5100 x 8000, half the desired size. It is rendering, as I write this I am on another machine, and I expect it will take about 14 hours. I think the next time I will try Dave's suggestion and render it in strips to get the full resolution I need and put it together in Photoshop. I still would like to know the formula for the memory thing...lol. Thanx!

Captain Obvious
10-22-2006, 04:42 PM
What the heck are you rendering that needs that kind of resolution? For A1 size prints, you almost never need a higher PPI than 100 or so.

Exception
10-22-2006, 06:31 PM
Split your image up into vertical strips, not horizontal ones. Horizontal pixel width determines memory usage in LW (vertical is taken care of by memoery limit setting).

Dave Jerrard
10-24-2006, 12:02 AM
My end target was 34" x 58" at 300dpi, I know LW renders at 72 dpi,Actually, LW doesn't render at ANY DPI. It just renders. That 72 is being assumed by whatever other software you're looking at the image in. As I've mentioned in other posts on the subject, DPI is a PHYSICAL characteristic of an output or input device, like a monitor, scanner, printer, etc... and it can't change (without some severe hardware modifications). It's a physically built into the device. You're thinking PPI (Pizels Per Inch), but that's a meaningless value UNTIL you specify an output size. On my machine, the images rendered by LW are never 72 DPI. My monitor has a resolution of ~100 DPI (It's an LCD monitor with physical independent pixels), so anytime I view a rendered image on it at 1:1, the image is displayed at 100 PPI. If I print that same image, the PPI is dependent on how large I print the image. But no matter how hard I try or what settings I use, I can't change the DPI of my printer or monitor. My monitor was built with 100 display pixels per inch and my printer's dots are ~1/12,000th of an inch in size (1200 DPI).



so I had to calculate the pixel number to 10200 x 16000 pixels, 16,000 is LW 9's limit. This would not fly. Segment Memory was set to 100MB, I tried many variations from 1MB to 3000MB, this didn't work either. So I have tried to render at 5100 x 8000, half the desired size. It is rendering, as I write this I am on another machine, and I expect it will take about 14 hours. I think the next time I will try Dave's suggestion and render it in strips to get the full resolution I need and put it together in Photoshop. I still would like to know the formula for the memory thing...lol. Thanx!

That's a pretty high resolution for such a huge output size. Even Triskelion's recommendation of 100 PPI is a bit high. You should be able to crank that out at about 50 PPI (1700x2900) or around that range. Remember, the viewing distance for something that large is going to be a bit greater than arm's length. The further the image is intended to be viewed from, the larger it needs to be. The output resolution doesn't need to increase. Billboards are printed at about 5PPI, or even less. I've seen their halftone screens and the dots on those can be a good 1/4 inch in size (4-line screen). Compare that to the typical screen size for a newspaper (65 LPI), or a magazine (85-133 LPI). Then compare how each is viewed.

As for LightWave, I think the formula is 196 * Width * Height = Bits. The 196 might be higher now, I'm not sure, but LW renders everything internally in floating point, and there's other buffers it has to keep track of at the same time. Assuming the 196 is correct, then your image, with a target output of 300 PPI would be 196*10200*17400=34,786,080,000 bits, or (divide by 8) 4,348,260,000 Bytes... that's 4.384 GigaBytes. At 100 PPI that would be 1,449,420,000 Bytes (1.44 GB), and at 50 PPI, your memory requirements would be a much more manageable 724,710,000 Bytes (742.7 MB). That's assuming the 196 is the correct value though.

He Who Has Been Doing Test Renders At 3k Lately.

starbase1
10-24-2006, 03:41 AM
Are you letting the image viewer display the image and relying on saving once it is shown? This can use up enough memory to cause problems.

I have managed to get more out by turning display off, and rendering directly to disk. Also try saving to a simple format rather than a complex compressed one - e.g. BMP not JPG.

You can make lightwave use a LOT less memory itself for the scene by using PNG not JPG for the textures, and if you can reduce image maps to 256 colour indexed PNG you will save a LOT more. I found you can get away with a surprising amount using this method.

You can see how much LW is actually using by using Ctrl-Alt-Del to bring up task manager, and locating LW in the list. You will see memory use go up and down a lot as it does its thing!

Quite apart from the considerations others have mentioned (And I have had 1m x 70cm that look fine from 4000x3000), I have to ask, have you really got detail to render at that incredibly fine level?

Dan_NT
10-24-2006, 08:28 AM
Dave Jerrard pretty much has all the bases covered on the technical aspects of rendering and printing. It's a matter of memory and LightWave, as with any 32-bit program under Windows, can only access a total of two gigs of memory. Having more than two gigs is good because you still need your background operations and explorer to run off something, at least a half gig overhead would be nice.

64 bit is the same, just multiply everything by two. So LightWave 64-- which doesn't cost anything to upgrade to if you have LightWave 8 or 9 already-- would be able to utilize four gigs of RAM.

So it's really a matter of memory limitation, and you can get to a point where even if you have segment memory limit at just 1MB you can try rendering an image just too big regardless of the RAM you have. My recommendation for a workaround is to render the image in actual segments-- render the top half and bottom halves independently then combine them together in an image editing program later.

Exception
10-26-2006, 02:53 PM
render the top half and bottom halves independently then combine them together in an image editing program later.


Nooooooooo, the LEFT half and the RIGHT half...
The vertical segmentation is taken care of in the camera memory setting, the horizontal segmentation is what you can do yourself. If your horizontal resolution exceeds your memory capacity, you'll have trouble.