Cheatsheet: How to get a Cleaner image with SP3

[padre.ayuso]

boh, I think I have tried in the past with HDR and did not help for me. But I can give it another try in one of my next scenes and see how it goes. Same principle though and the convenience of putting a plane light is being able to give the same K value the camera has and thus achieve my white balance with no messing around with color tweaks.

[Streetwise]

it improves the quality but not the effect I'm going for.

Yes, - bank lighting with softboxes. I agree on speed, but there's a definite look that you get with HDRI in that way the shadows behave relative to the nature of the sun in the HDRI. You can't capture that with the plane lights.

As for adding portals to the windows, I had heard that they add a lot of additional time and are no longer needed for HDRI.

[padre.ayuso]

As for adding portals to the windows, I had heard that they add a lot of additional time and are no longer needed for HDRI.

That's what I heard too. So in the case you have high render times and lots of noise, you may want to try the bank lighting approach, if it makes a difference, then you may want to try that one for that one particular scene.

[PIXELBOX_SRO]

yes i have heard too that when usign HDRI its not advisable to use light portals anymore...which is weir cos i alwas thought theyre used to concentrate the GI samples in the opening.
Are the portals obsolete then with the new sampling method?

[Mokiki]

Why not use a light portal then?

I was under the assumption that Light portals won't do much for Brute Force renderings? Is that wrong?

[^Lele^]

I ought to have asked for elucidations instead of assuming, here.
Where is the HDRI placed? Envitonment, env. override, domelight?

[Streetwise]

Domelight for me.

[joconnell]

I ought to have asked for elucidations instead of assuming, here.
Where is the HDRI placed? Envitonment, env. override, domelight?

I did a pass over bobby's scene and the hdri was in a dome light, portals didn't help at all. Again the windows were tiny so a hdri was wasted.

[Pixelab]

As discussed in other threads, Domelight + HDRI generates a noise more noticable than the other effects.

Only solution for me is either

- Switch to Local subdiv (not really advisable since Vray 3) and increase HDRI dome subdivs to 200/300

- Increase MSR to higher values if you stay in "automatic" subdiv mode (a lot if you work with high AA noise thresold like me)

A forced multiplier in the domelight (like in the VRay light properties), while keeping the benefit of the automatic mode would be really nice in the next upgrade.

[Lupaz]

what's msr again?
min sample rate?

[joconnell]

Yep - a quick way of specifying how many shading samples get done for each aa ray. If you put in 4 for your minimum shading rate, you'll get roughly 4 times as many shading samples as aa samples for example.

[Streetwise]

what's msr again?
min sample rate?

Min shading rate. The default is 6.

[vlado]

A forced multiplier in the domelight (like in the VRay light properties), while keeping the benefit of the automatic mode would be really nice in the next upgrade.

We can add this to the V-Ray light properties dialog, if that's ok? I really don't want to add another spinner to the light itself.

Best regards,
Vlado

[PIXELBOX_SRO]

light properties sounds great Vlado indeed.

would anyone clear the haze around the light portals please? when and whn not to use them with the new sampling.
Or is this something that we can expect to be changed in near future?

It kind of funny that with every bigger update we always have these threads about how to tackle noise...for someone who is not a frequent forum reader this might be a topic to miss.

Can we make such important talks sticky or somewhat more visible???

[^Lele^]

light properties sounds great Vlado indeed.

would anyone clear the haze around the light portals please? when and whn not to use them with the new sampling.
Or is this something that we can expect to be changed in near future?

It kind of funny that with every bigger update we always have these threads about how to tackle noise...for someone who is not a frequent forum reader this might be a topic to miss.

Can we make such important talks sticky or somewhat more visible???

The dome light has importance sampling of the hdri in it, so it will help rays go in the places which are the most relevant to getting the lighting right.
In that case, as John well pointed out, there is no benefit whatsoever from a light portal, which served/serves the same function the domelight has for general background bitmaps (ie. it will tell vray to walk through the light portal and see what is behind it. That's important, please sample it.)

Using a dome to light an interior from a small aperture is a waste, again as pointed out by John, as the small aperture will anyways let in a beam of the color and intensity behind it, no particular character to the lighting can come from tiny windows when sampling a huge spherical BG, so one's better off with a normal arealight behind the window simulating the environment.