Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: philippelamoureux on 2015-01-31, 06:03:46

Title: Using Sun + HDRI at the same time?
Post by: philippelamoureux on 2015-01-31, 06:03:46
Hi guys, I'm making a day scene and I want to have a nice hdri for my sky but I also want interesting shadows from the corona sun. Is it possible to use both? I don't seem to get very good results. Trying to match the hdri brightness with the sun intensity...is it just a matter of trying to make them fit well or there is another easier trick? Thank you.
Title: Re: Using Sun + HDRI at the same time?
Post by: maru on 2015-01-31, 14:29:46
With a good HDRI you should be able to render realistic skylight+sun shadows.

Depending on what you are doing, you can use your HDRI as just direct visibility override (for reflections, refractions) and use Corona's Sun+Sky for lighting. Or you can remove the sun from HDRI in photoshop and use Corona's sun.

There is also this:
https://coronarenderer.freshdesk.com/support/solutions/articles/5000516732
Title: Re: Using Sun + HDRI at the same time?
Post by: philippelamoureux on 2015-02-01, 02:11:10
I've been able to achieve something decent by putting the strength of the corona sun to 0.1 and use a vray hdri with gamma 2.2 for background/reflections etc. (it's a good hdri, from noEmotion, 15000 pixel wide). I'll do some more tests just with the hdri today. Thanks for your tips!
Title: Re: Using Sun + HDRI at the same time?
Post by: rambambulli on 2015-02-01, 20:53:41
That resembles my setup. A good HDRI won't need a sun. Setting  the gamma to 0.75 also helps to create more pronounced shades.
But I you use I use a sun I would set it between 0.05 and 0.15 and sync it with the brightest spot in the HDRI.(These values are relative to the intensity of the HDRI of course).
Sometimes I resize the sun size to max 3.0 with a soft HDRI.
I you do this check the sun color. Sometime this doesn't match the HDRI tone.

post some of your tests.

good luck.