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neilp
06-01-2005, 09:05 AM
Can anyone please explain how i achieve what is explained below in the LW 7 manual. If this is not simply turning off volumetrics lights in the global illumination panel then I am stuck!!! any help much appreciated.

Dodgy
06-01-2005, 10:38 AM
It means volumetric effects like Hypervoxels/Ground fog. I don't thinl it's referring to volumetric lights at all.

neilp
06-01-2005, 11:13 AM
Fair play, I realised that I could disable via the effects panel...I was just confused as to WHY i would have to add this command to a menu or a shortcut to access is??
Alternatively, am I missing something hidden somewhere that will speed up my rad. renders..

toby
06-01-2005, 08:44 PM
There's several things you can do, but it depends, what are you rendering?
Backdrop Radiosity is much faster than the other types, but does not calculate bounced or luminous light sources.
If you know how to adjust Interpolated radiosity it can be much faster than Monte Carlo, but it's generally not accurate enough for animations, where you will see flickering.

neilp
06-02-2005, 02:24 AM
Thanks Toby,
I'm rendering building exteriors: I use a luminous white skydome to give a soft gi effect. (still images only)
radiosity settings as below.

some sample renders also
I have adjusted these settings to achieve fast renders but I never get the quality I am looking for!!
Have you any advice regarding settings?

Captain Obvious
06-02-2005, 02:55 AM
I have adjusted these settings to achieve fast renders but I never get the quality I am looking for!!
Have you any advice regarding settings?
Set the tolerance fairly high. Turn off "cache radiosity." Render using motion blur. The more AA passes, the better your radiosity will be.

toby
06-02-2005, 12:21 PM
Interpolated with a tolerance of 0 is the same as Monte Carlo. Try 0.2 to 0.25, settings between 0.0 and 0.2 can take longer than monte carlo, and look worse.

Each anti-alias pass with this setting will look very blotchy, but render very fast, and when you turn on motion blur (turn off cache radiosity) and high AA, the radiosity will be recalculated for each aa pass and then they're averaged together. Also put evaluation spacing pretty high, like 1m, and rays per evaluation higher than normal, like 6x18; it doesn't add much time and it helps. If it still looks blotchy with high or extreme AA, lower the evaluation spacing.

You might also try Backdrop radiosity, remove the skydome and set the backdrop to white, maybe pale blue at zenith - rays set to 4x12 is usually good enough.

neilp
06-03-2005, 02:27 AM
toby
I tried your suggestion thanks, do you know why my image appears darker when I do this?

toby
06-03-2005, 02:47 AM
backdrop or interpolated? if it's backdrop radiosity, it will be darker because light isn't bouncing around, from the ground for example. I'm sure that with interpolated you can simply turn up the intensity -

neilp
06-03-2005, 03:03 AM
interpolated, I can easily turn up the intensity - but do you know why it is darker?

phrick
06-03-2005, 11:00 AM
Skip the skydome and use the LW_TextureEnvironment instead (backdrop/environment settings).

Create a gradient with "Pitch" as input parameter. Add some keys (I usually use black and white colors only, or colors with very little saturation)

It's been a while since I rendered anything at all, but If I'm not mistaken this is a faster alternative which also looks better.

toby
06-03-2005, 12:09 PM
interpolated, I can easily turn up the intensity - but do you know why it is darker?
No idea!
How is it looking, can you post another image? How's the render speed?