View Full Version : Lighting issues in LW 9.2

Bodger Bowham
07-31-2007, 06:37 AM
I am having a problem with what appears to be the lighting in my Lightwave Layout.

When I render a scene on my computer, everything seems to run smoothly. However, when I render the exact same scene file on another computer in my office, the lighting appears brighter, giving me an over-exposed image.

I have looked at my light properties and FPrime settings and they are exactly the same on both PCs, as are the surface styles.

I have noticed this problem with only 2 of my scene files (I produce several a day).

I get the feeling this may be an FPrime plugin issue rather than a Lightwave one, which I have recently upgraded from 9.0 to 9.2.

Anyway, I have attached the good render and the over-exposed one so you get an idea what the problem is.

Can anyone shed some light on this issue?


07-31-2007, 06:42 AM
If you are still using FPrime 2, and you are using area lights it's because area lights changed in LightWave 9.2, and were matched in FPrime 3.


07-31-2007, 08:07 AM
By the same token, if the other PC isn't running 9.2 then the Area lights will be blown out due to the same change.

Bodger Bowham
07-31-2007, 09:22 AM
Sorry, should have clarified.
Both PC's are in my office and are both running Lightwave 9.2 and FPrime 3.2

07-31-2007, 04:09 PM
Is there an Fprime 3.2 update?

07-31-2007, 05:03 PM
are the PC's EXACTLY the same. Try rendering on PCs that are EXACTLY the same. Then you can really narrow down what's causing the difference. My laptop renders better than my PC. It has more memory, faster processor.

08-01-2007, 12:37 AM
I would contact Worley on that one. They *should* be the same, because the math is the same, and it's more likely the renderer than the layout (LW).

08-02-2007, 05:18 PM
I've had the same problem, even with the old frprime 2.1 and lw 8.5. It only happened to me when i was using area lights. The intensities would differ.

08-02-2007, 07:47 PM
I loaded up both images and flipped back and forth between them. It looks to me like the camera position has been changed. If so, the lighting may be effected because of the camera shift.

Ron Mills

08-02-2007, 08:22 PM
Don't think it's this, but have you tried trashing your config files and letting LW rebuild them?

Bodger Bowham
08-07-2007, 05:02 AM
The camera has not changed, I must have cropped the images at some point.

I have tried trashing the config files, with no luck.

08-07-2007, 10:08 AM
The computer with the bright render... if you cut the area light intensity in half... is the problem fixed?

I seem to recall if layout opens an old scene, intensities of area lights are automatically doubled. Compare the values, and see if that is actually the case. Then it's not Fprime's fault but somehow one computer does double the intensity, and the other doesn't. Perhaps saving out the scene again from 9.2 will fix it on both?

Bodger Bowham
08-08-2007, 02:38 AM
Exception, I have tried halving the area light intensity in the brighter render.
I have attached thumbnails of the good render unchanged, and the brighter render with the intensity now halved.
They are not identical but are indeed very similar, so you seem to have the right idea. Do you know why this happens?
What seems most strange to me is that this has only happened with a handful of my scene files.

08-08-2007, 08:50 PM
have you tried rendering without F-Prime and changing the lights to something other than area lights? after this are they still showing intensity changes? if not then you know the area lights are messing you up; either re-make them (write down location and rotation) and see if that helps...