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View Full Version : What's up with those dome lights ??



michaeldejong
11-22-2013, 05:09 PM
Question guys, at what point will my dome light stop making my scene look like it has television noise over all shading/shadows ? (especially when objects are animated)

I've been experimenting with some values and rendering out to 400*300 just to test, and I was using extreme settings of 20 min samples 100 max samples and even higher.
Still, extreme noise.

Basically any feedback that speaks to what is causing this, how I can (hopefully) solve it, or if this is just what to expect with a dome light.

I wanted to ask the LW community about this before I start an animation that may take up to half an hour per frame if I am still using too low of settings.

Thanks Guys! Have an awesome weekend.

RebelHill
11-22-2013, 05:30 PM
at what point will my dome light stop making my scene look like it has television noise over all shading/shadows ?

when you get a good handle on using the US/AA system (:


http://www.youtube.com/watch?v=UgNB9tZWUmM

prometheus
11-23-2013, 01:44 AM
what lightwave version?

lightwave 11.6?... go to render globals, render tab,light samples, should be enough with approx 4-8 light samples to get rid of domelight noise, for some finer reduction it might also be dependent on the samples in the camera render tab minimum/maximum samples, but you donīt need that high samples for that... but first check the render tab for light samples, the shading samples above that has no effect on the dome light what so ever.

Michael

sukardi
11-23-2013, 02:37 AM
Make sure you set angle to 0 - 10. The default 90 is useless...

4dartist
11-23-2013, 10:51 AM
I agree with prometheus, it's definitely the light samples. I think newer builds of lightwave default to 1. Even VPR turns it's nose at that, and renders poorly, but setting it to 6, maybe 8, it looks fine.

I disagree about 90° dome lights being useless. In outdoor scenes, it can be a nice fill from the sky instead of running Radiosity. It's not as fast as interpolated Radiosity, but it seems much faster than full up Radiosity. I've never had much luck running animations with interpolated, so I've turned to dome lights as an in between.

RebelHill
11-23-2013, 12:21 PM
it's definitely the light samples. I think newer builds of lightwave default to 1.

Whilst its true that its samples... its not simply just light samples... Whilst you'll certainly get better results by bumping them up, you'll also waste sampling where its not needed, increasing render time (sometimes a lot). You will often want to increase base light/shade samples above 1... but very rarely do you need more than 4.

Samples are (broadly speaking) interchangable (see first 2 panels of the image)... to get the best quality at the best rendertime cost involves playing around between where you "call" samples from to find the optimum speed balance.

4dartist
11-23-2013, 01:18 PM
Good point. Good video too.

spherical
11-23-2013, 03:38 PM
Use DPont's Dome. It has individual samples setting, in addition to Unified, then you can leave the other global sample settings down to better levels. Many of Denis' lights have individual sampling.

Greenlaw
11-23-2013, 04:13 PM
Make sure you set angle to 0 - 10. The default 90 is useless...

I find 90 is fine if you're going for an ambient or fully overcast lighting look.

For the B2 excerpt we released a couple of months ago, I mainly used about 40 degrees for Dome, which gave me a little directional lighting to make the scenes pretty while keeping the shadows super soft, even though 'realistically' the environment is fully overcast.

As for the noise, yeah, you need to increase your light samples. In the past, the default setting used to be 8 but it was dropped to 1 in recent versions of LightWave.

FYI, this is true for DP lights too if you enable the LW Unified option.

G.

spherical
11-23-2013, 04:19 PM
FYI, this is true for DP lights too if you enable the LW Unified option.

Yes it is. Disabling LW Unified, which is enabled by default, allows a higher/lower sample for just that one light; eliminating the need to over-crank the light samples globally to get rid of noise from a light that has a severely larger area than most others and cut the render time.

prometheus
11-23-2013, 05:18 PM
Make sure you set angle to 0 - 10. The default 90 is useless...

Not entirely, the dome light with 90 degree angle is useful for overcaster light, for direct feedback in environment scenes..otherwise you have to set ambient occlusion shaders for the scene.
so domelight with sunlight gives a pretty decent exterior lighting setup.
0,52 angle for domelight-hard sunlight, and 90 degree angle for the shadows and 90 degree rotation of the pitch for the skylight overcaster occlusion, or use dponts sk_sun light for the harder sunlight with a 0,52 default setup.

Update edited...ah..I missed the other following posts, more guys than me that thinks the domelight is useful for exterior overcaster.
I would gladely see some improvements on the speed of the domelight though.

Michael

BeeVee
11-25-2013, 02:28 AM
Make sure you look at the docs. The section starting page 44 detailing the changes to Universal Sampling for 11.5 talks about exactly your issue... (I do write them for a reason you know ;))

B