View Full Version : Problems With Large Renderings

01-20-2005, 03:49 AM
We're trying to produce the largest, sharpest still renderings possible. The ideal setup is in XGA format @ 400% image multiplier with high antialiasing. The problem is, after endlessly adjusting segment memory it will finally run (4.5 hours) but produce no image with image viewer or assigning a file format, name to save to disk.

Reducing the format size/image multiplier works just fine but won't produce the the sharp image we need.

This is on a new Dual G5 with 8GB of memory with LW 7.5C


01-20-2005, 06:31 AM
I render large (4,000-5,000 pixel wide) with no problem. I just put in the resolution (custom) I want and save it out as a tga (for Alpha) I am on a G4 1.42 (x2) with 2 gig of ram (LW 8). The viewer does not show me the whole image but when I open in PS it is all there. Hope this helps...


01-20-2005, 06:48 AM
Hmm, since this is no big resolution i see no problem. What actually does the image viewer display ? If its just black, don't worry, if you go down to 25% in image viewer it displays the image fine.

01-20-2005, 07:00 AM
When we render at 200% the small image preview shows the rendering in progress and when finished the larger finished image pops up-no problem. However at 400%
the rendering in progress works but when finished there's no finished image window or file anywhere????


01-20-2005, 07:13 AM
If you render a large picture... the viewer is black, it' s normal; because the rendering is made by parts, start at the high of the picture...

Simply wait!

Or... in the renderig option , you must put "image viewer" at "render display"

01-20-2005, 07:58 AM
We've rendered images that were over 10,000 pixels wide (to be made into murals) with no problems. Granted, Lightwave gets pretty choked up at those resolutions, but it will still do it (just slowly.)

Cheryl, when you say you can't see anything in the image viewer, can you go to File-->Save RGBA and then open that image in photoshop? If that still produces no image, try setting the res. multiplier to 100% and just manually enter your size.

01-20-2005, 09:47 AM
When rendering the files at 100% or 200% resolution multiplier everything works;
we can see the rendering in progress and upon completion the machine beeps and
there's a image which we save to disk.

When we jack up the resolution to 400% we can see the rendering in progress but upon completion (beep) there's nothing to be seen except the small window with its' abort button.

In addition, we are getting a lot of "not enough memeory for rendering buffers" messages.

I think were in trouble.

01-20-2005, 09:51 AM
Hmmm... odd. Bad RAM, perhaps? Renders over a couple thousand pixels swallow up RAM, and if there's a bad chip, it might do that.

Basically what I'm asking is, if you enter your desired size (4096x3092) but leave the res. multiplier at 100, does it do the same thing?

01-20-2005, 09:54 AM
As mentioned before, what happend if you type the 4096x3072 in the width and height fiel and render at 100 % ?

If tthe "not enough memory" message appears you should switch off "show rendering in progress" and "render display", that saves some memory.

01-20-2005, 09:55 AM
Sorry for the lousy spelling!

01-20-2005, 10:04 AM
We tried entering the size manually but the program reverted back to 640X480 when it started to render. We're gonna try it again shortly.

Thanks for all the help.

We'll be back!

01-20-2005, 10:07 AM
Did you remember to hit enter or tab after entering the numbers?

(my appologies if that seems too obvious... it's just an easy mistake to make) :)

(lightwave is weird about not remembering entered numbers unless you hit enter, instead of just clicking out of the text field...)

01-20-2005, 10:13 AM
Correction: Error essage reads: "Not enough memory for frame buffers"

Will changing thread # help? We're currently using 4 threads?

01-20-2005, 10:16 AM
In the camera properties, under "segment memory limit", what does it say?

01-20-2005, 10:21 AM
Follow Up...Changed threads to 8, Setup at 2560 X 2048 pixels with enhanced high anti-aliasing so that we can at least check out the illustration. Seems to be working. Simple fact seems that large renderings above 3500 pixels simply aren't working for whatever the reason. And we're running up to the deadline as usual.

01-20-2005, 10:30 AM
Hey there Cheryl2 you really should consider getting RenderFarm Commander you can split your single imges up and have them render across different machines (and its really cheap and there is a demo version) We have been rendering out large images for print and have found that using this cuts our time down tremendously and you dont have to worry about all the problems your having

01-20-2005, 10:48 AM
We've played a lot with segment memory. Currently I believe its set at 8MB (Can't look right now) but we've set it at anywhere from 8MB to 1000MB with the result that the LW simply won't run the larger images. May have to totally reload the program and start from there.

01-20-2005, 12:04 PM
View render in progress and Image Viewer take up ram - the bigger the image the more Image Viewer needs. Turn them both off, set an output path under render options, and use F10 instead of F9.

01-20-2005, 04:30 PM
My recommendation would be to use Render Farm Commander - it worked well for me. Alternatively go with the save to pathname approach.

01-28-2005, 01:23 PM
Listen to Toby. And get more RAM if you can, at least 2 gigs.

If you have to output for print, which I do all the time, turn OFF display render in progress and display final render. Set your render options to render one frame only (start 0 and end 0 or whatever frame you want) and then set the RGB filepath to write the data to a disk.

Now, depending on the complexity of the scene, LW may not render at certain sizes. It will balk. LOWERING the segment memory limit helps with this, not raising it. When you LOWER the segment memory limit, you force LW to render the image in pieces, which allows it to tackle larger pictures.

For the size, I just leave it at 100% and input my size in the window as inches*resolution, since it is print. For example, if I am doing something that is 8" square with 1/8" bleed on all sides, it is 8.25" x 8.25". For width I type 8.25*300 and it calculates for me that 8.25" @ 300 dpi is 2475 pixels.

If the image will not render because it is too big (or too complex), and this will happen, you have a couple of options.

1. Deconstruct the scene. Duplicate the scene into many different scenes, and delete parts of it. Each scene will have fewer polygons, and simpler scenes are easy to render at large sizes. You will have to retouch this all back together in Photoshop, adding shadows and so on. It can be difficult. If your image has lots of reflections and so on, it is probably not the way to go.

2. Reduce the resolution. Instead of 300 dpi, go down to 250, then 200.

Another thing that might help you, and I haven't tried this myself yet so it is just a theory, is to rotate the whole 3D space if the image is landscape. Lightwave segments the image vertically, so if your image is really wide then it will still have a lot to deal with in each segment. Add a null to the scene and parent EVERYTHING EXCEPT THE CAMERA to the null, and bank the null 90. Change the camera dimensions and suddenly your landscape image is portrait dimensions, and will segment better. I think.

Hope this helps. I often find myself rendering complex scenes that the client wants at huge sizes at lower-than-desired resolution. There is no way I can render a hugely complex scene for a 48" wide poster at 300 dpi!! Besides, who is looking at a poster of that size up close anyway??

Remember, even photographers are working with a certain film size, and then the image is enlarged. It's the same for us. I have 4 gigs of RAM on my machine, but LW can't use all of it.