View Full Version : Render itme in Lightwave 9

08-31-2006, 06:31 AM
I'm rendering out a scene in Lightwave 9 and I'm really surprised at how slow it is. I wouldn't call the scene exactly complex, it has around 100,000 polys, one area light with two point lights and a few objects with refraction and reflection on.
I've switched all the render raytracers on so shadows, reflections,refraction and transparency which of course will slow it down. There's no Radisoity and no complex shaders. The scene is taking over an hour for one frame. The bizarre thing is that I'm sure yesterday I done a test render with all the settings mentioned above and it took around 14 minutes which seems about right,which makes me think maybe Lightwave is having some memory leaks? The most annoying thing is Lightwave doesn't seem to use the whole processor, when I look at the stats my processer is only running at 50% I've always assumed Lightwave would grab as much processer as it can get?

Is anyone else having this problem?

Pete B

08-31-2006, 06:53 AM
Hi !

1. Did you set your multithreading in LW to proper value (i.e. 2 procesors - 2 Threads and not 4 or 1)
2. What camera type you used for rendering ? In Lw9 there is several new camera types which have NEW render core/alhorithm which is faster than old one in most of situations. But you also have old "classic" camera. Switch to Perspective camera and then try to render.
3. Also set your Ray recursion limit to lower number like 4-6 or so instead default 16

what CPU/configuraiton you use ?

08-31-2006, 12:13 PM
Well it's set at 1 thread at the moment but I'm running a single Pentium 2.4 ghz so I would have thought this was right, no?

The camera is set to perspective and I kept rays at 16 as I was worried that it might start missing certain things out I did try it at 12 but it didn't make much of a difference to the render speed. I'll try 4 and see what happens.

Thanks for the reply

Pete B

08-31-2006, 12:41 PM
Ok done another render and wow what a difference. I turned threading to 2 instead of 1 and it now uses 100% of the cpu. Also turned down ray recursions and turned on adaptive sampling (I forgot last time). So from a render time of around 1hr 30 minutes per frame it's now down to around 11 minutes.

Nice one Lewis

08-31-2006, 01:19 PM
You maybe have Hyperthreading CPU so that's why it says 2 CPUs and works better wiht 2 threads :).

Good to have problem solved

09-01-2006, 11:23 AM
Just out of interest what is the best setting for an Intel Conroe E6600? Is the correct setting 2 threads?

09-01-2006, 04:10 PM
Hmm !

2 Threads should be best (only wiht Perspective camera) if is not Hypethreading CPU but if it has hyperthreading windows will see it as 4 processors so it might be good to set as 4 also. I'm not sure about those new Intel marks so i don't know which ones are HT and which aren't. Try 2 and 4 and see which one is faster.


09-02-2006, 12:39 AM
You mght want to try this with the classic camera too, it ay be even faster. As I understand it Classic works best wih fairly simple scenes, perspective camera works best with very high poly counts (millions) and intensive ray tracing. Your scene has a fairly low poly count but quite a bit of ray tracing so it's difficult to choose the camera, it's worth trying both!

09-02-2006, 03:14 AM
Yes this is very nice change comparing to old style manuals :).