Light Portals or Dome Light - which one is faster/better

[vmulhem]

Hi all, I'm sure this has been covered before but I just need a conclusive direction.

What's the best workflow in vray 3.50.04 for lighting interior spaces in terms of speed, quality etc. and why. (considering BF/LC vray defaults are used).

1. Vray sky - light portals+env or dome light?
2. HDRI - light portals+env or dome light?

A clear guidance from Chaosgroup would be welcome.

Thanks

[vmulhem]

Anyone from Chaos Group please could you help with this. We recently discovered a bug with sky portals and are now forced to use dome light. We have been using sky portals for years. Now unsure as to the best approach.

[vlado]

Light portals have never worked well with the dome light.

I've done some tests recently to see if it still makes sense to use portals, but it looked like they don't really help that much anymore. So I'd generally recommend to just use a dome light and no portals.

We will be adding some more logic to automatically make sampling of openings more efficient so there will be even less reasons to use portals in the future.

Best regards,
Vlado

[TutanMark]

Thanks Vlado! i was thinking to be crazy

[Pixelab]

We will be adding some more logic to automatically make sampling of openings more efficient

I love this kind of statements. Yes, more Vlado logic !!

[vmulhem]

Thanks for clarifying Vlado. So I guess that applies to both HDRIs and VraySky - just stick them in the dome light and render.

[andybot_cg]

I was just testing this for myself recently. While there didn't seem to be a time savings, the portals did help bring more light to the interior than without.

[PIXELBOX_SRO]

so when using vray sky and sun as primary source of light, its better to map vraysky to a dome light and not use portals?
or am i ok using vray sun/sky and portals if i dont use vray dome light?

i am asking because adding portals when using vraysky/sun significantly reduces noise and make the sampling more efficient.

[PIXELBOX_SRO]

so basically using:
vray sun + sky in environment slot + light portals is much much faster and cleaner
THAN
vray sun+ sky mappend onto vray dome light and without any portals

i am speaking about 2x faster render times and very clean renders even at 1/24 AA and MSR at 6

[joconnell]

That's a bit of a shame, it's very handy to have the domelight with your sky map since you can light select it.

[PIXELBOX_SRO]

we will need probably Vlado confirming this and i have no problem providing a test scenes for both cases

[PIXELBOX_SRO]

just bumping this one....i know youre guys busy with the 3.6 but is the above described behaviour normal?
Cheers
M

[OPEN_RANGE]

this was interesting for me to find out. I am working on a fairly simple interior arch viz scene. Using physical camera. Lighting is vray sun with vray sky in the vray environment map slot. After reading this thread, I added vray plane lights to all the windows and setting them as skylight portal w/ simple checked. Makes a big difference. Rendering time doubles but scene is much better lit with way less noise. Absolutely worth it for the quality it achieves. Never new that would make such a difference, (did not get the memo i guess).