Interior lit by HDRI DomeLight - am I insane?

[AndresAhumada]

i always use blurred ibl for gi pass. Just so much better than a vrays sky to get all those variations and so on.

agreeee!!! 100%

[peterguthrie]

Here you go, better late than never: http://www.peterguthrie.net/blog/201...-for-interiors

my conclusions:

- Use my HDR skies (obviously!), or Thomas Suurland's or CGSkies or wherever does good ones these days.
- I think good quality hdr skies in a vray dome light gives a really great quality of light that can't be matched by an artificial sun sky system.
- Don't bother blurring or resizing HDRs down for lighting. Full size ones have always worked great for me and I never even considered resizing them it. Look at the difference in the quality of shadows, and it doesn't even speed things up that much.

And a disclaimer, I'm only interested in the best quality stills. I never do movies, but if i did then I might consider vraysun and irradiance map GI, but I don't, so I don't

finally, I bet there are loads of technical inaccuracies, or even misunderstandings on my part, go easy on me!

[Neilg]

The thing i've always noticed about the sun/sky is the way the yellows from the sun and the blues from the sky mix to create a green tint over the whole image, where with hdri's the blues and yellows/reds seem to stay where they belong.

[eyepiz]

Here you go, better late than never: http://www.peterguthrie.net/blog/201...-for-interiors

Nice guide!...Which HDRI did you use for your sample scene?

[AndresAhumada]

Here you go, better late than never: http://www.peterguthrie.net/blog/201...-for-interiors

my conclusions:

- Use my HDR skies (obviously!), or Thomas Suurland's or CGSkies or wherever does good ones these days.
- I think good quality hdr skies in a vray dome light gives a really great quality of light that can't be matched by an artificial sun sky system.
- Don't bother blurring or resizing HDRs down for lighting. Full size ones have always worked great for me and I never even considered resizing them it. Look at the difference in the quality of shadows, and it doesn't even speed things up that much.

And a disclaimer, I'm only interested in the best quality stills. I never do movies, but if i did then I might consider vraysun and irradiance map GI, but I don't, so I don't

finally, I bet there are loads of technical inaccuracies, or even misunderstandings on my part, go easy on me!

MANY MANY MANY MANY MANY THANKS!!!!!
Best mentor for HDRI light source!

[alexyork]

Nice work Peter.

It's very interesting that the HDR seems to produce shadows that are both sharper *and* softer in different places than the VRaySun. Very strange! The VraySun is somewhat too sharp in certain areas and too soft in others compared to the HDR which seems more balanced.

Very interesting...

[Crush]

Here you go, better late than never: http://www.peterguthrie.net/blog/201...-for-interiors

my conclusions:

- Use my HDR skies (obviously!), or Thomas Suurland's or CGSkies or wherever does good ones these days.
- I think good quality hdr skies in a vray dome light gives a really great quality of light that can't be matched by an artificial sun sky system.
- Don't bother blurring or resizing HDRs down for lighting. Full size ones have always worked great for me and I never even considered resizing them it. Look at the difference in the quality of shadows, and it doesn't even speed things up that much.

And a disclaimer, I'm only interested in the best quality stills. I never do movies, but if i did then I might consider vraysun and irradiance map GI, but I don't, so I don't

finally, I bet there are loads of technical inaccuracies, or even misunderstandings on my part, go easy on me!

Well this is nice and all, but using an HDRI with a generic light grey material in a test scene is no good. Try cleaning a scene with full blown production materials. I'm talking about slightly glossy wall paint, silky glossiness with multiple layers for the wood on the shelves etc. You will run into all sorts of noise issues from specular highlights to reflections of glossy reflections. Rendertimes will go way up. Just saying.

I love to use HDRI lighting, even for interiors, as the subtlety of real world lighting cannot be matched by a simplified model as the vray sun and sky. But production requirements, especially for animation, make this very hard to use in some cases.

[peterguthrie]

I could have done the article with full materials, but it already took me a whole day and I need to work as well

Don't people think it's interesting that if you are committed to using universal settings, or brute force (as I am) that the HDR version actually rendered quicker than the Vraysun version?

[peterguthrie]

Nice work Peter.

It's very interesting that the HDR seems to produce shadows that are both sharper *and* softer in different places than the VRaySun. Very strange! The VraySun is somewhat too sharp in certain areas and too soft in others compared to the HDR which seems more balanced.

Very interesting...

The vraydomelight is just one big light really, and happens to have a sun in it. So I guess what you are seeing is less sharp shadows from the hdr sun but then there are more defined shadows from the rest of the sky, whereas the vraysky is just contributing to GI. If you look at the vraylighting element on one of the vraysun renders and compare it to the vraylighting element from a hdr sky render you can see what i mean. Correct me if i am wrong someone!

[alexyork]

The vraydomelight is just one big light really, and happens to have a sun in it. So I guess what you are seeing is less sharp shadows from the hdr sun but then there are more defined shadows from the rest of the sky, whereas the vraysky is just contributing to GI. If you look at the vraylighting element on one of the vraysun renders and compare it to the vraylighting element from a hdr sky render you can see what i mean. Correct me if i am wrong someone!

This makes sense to me. Sounds like the likely explanation. Very tempted to try out HDRs for interiors now.

[Morbid Angel]

This makes sense to me. Sounds like the likely explanation. Very tempted to try out HDRs for interiors now.

my only concern would be that you will be tracing very large light (dome) through a very small window, so you may need lots of samples there. Domelight's purpose was/is to light exteriors, approximate gi lighting (bf) at no bf costs.

[Crush]

Since the original poster asked specifically for HDRI lighting in interior animation, let me add some thoughts to the discussion:

The paradigm of "image quality first, render time is secondary" isn't going to work for animation.
Most archviz shops I know of are rather small businesses with limited hardware access. For most projects, you've got a limited budget too.
Therefore, render time becomes a mayor issue if you have to crank out thousands of frames. Therefore, going for maximum image quality isn't always possible.

Sure, you have to optimize your scenes. That is craftsmanship you have to learn. Read the documentation, do render tests, check out the tutorials about scene optimization, some written by the very same guys posting in this thread.

Still, sometimes - and this depends on your scene - just dialing in your subdivs doesn't cut it. Then you have to make hard decisons and sacrifice image quality for render speed.
Precache your GI, so goodbye to Brute Force. HDRI is giving you a hard time? It may be better to store the domelight to Irradiance Map and forget about those speculars. Or get rid of the HDRI and approximate it with Vray Sun & Sky.
Do you really need all those glossy reflections everywhere? The list goes on...

It basically comes down to managing your ressources. There is no silver bullet.

[Morbid Angel]

I agree, however he also asked how to get the image to the next level of quality, so he is interested in taking it to the next level. I had a run at his scene. After I was done with it, it took 18 minutes on my dual 6 core xeon for final frame, grain free etc. That is quite acceptable, using hardware that's 5 years old. So not to disagree with you, but also, there are steps to be taken and $ to be spent, if you want to keep up with the trend. Like, upgrading to vray3, will also cost you a bit.

[Neilg]

Do you really need all those glossy reflections everywhere?

the answer to this question is nearly always yes though...

[Morbid Angel]

the answer to this question is nearly always yes though...

EVERYTHING has Fresnel!