[Sidefx-houdini-list] rectangular pbr area light

Erika Salatiello tictacer at hotmail.com
Fri Dec 7 15:21:53 EST 2007


what was the highest you tried for a pixel sampling rate? it's possible you may have to go higher - i've had to use values above 60 before.  By default, in less you really go crazy with it, I think you're always going to have a  bit more noise with pbr> Date: Fri, 7 Dec 2007 18:03:44 +0100> From: lulu at alamaison.fr> To: sidefx-houdini-list at sidefx.com> Subject: Re: [Sidefx-houdini-list] rectangular pbr area light> > Mario Marengo a écrit :> > On December 7, 2007 09:13 am, Luc Froehlicher wrote:> > > >> is it possible to have rectangular area light (H9 PBR) ?> >> luc> >> > >> > If what you want is a *square* area light (not rectangular), then you can use > > an area light set to "Grid". You can choose among several basic symmetrical > > shapes with this approach, and it works in every rendering engine.> > > well I need to mimic kino flo's type of light.> I noticed that if I edit the interface there's a parameter vm_areasize > in Mantra/Light> (2 floats array) but it doesn't seem to have any influence.> > If you want an actual rectangle, or some other arbitrary shape, then create > > the emitter geometry and assign it a constant shader (vex_constant will do), > > then make sure your ROP's "Diffuse Limit" is set to 1 or higher, else you > > won't get a diffuse contribution (Glossy Limit defaults to 1 I believe, so > > you'll get one bounce of specular, but no diffuse, by default).> > Anyway, I guess the main point is: assigning a constant value (as opposed to > > bsdf) to the global F in a shader is equivalent to defining an emitter with > > the given value as its power.> > Also, you'll likely need to raise "Pixel Samples" in the ROP to something > > higher than default to reduce sampling noise.> > > I tried that and increased the diffuse value but , as you say , it's > very noisy :(> thanks for helping.> luc> >> > > > > _______________________________________________> Sidefx-houdini-list mailing list> Sidefx-houdini-list at sidefx.com> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
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