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IBL with sunlight
Posted: Tue Jul 27, 2010 11:29 am
by big K
i am not sure, but wasn´t there an option to add the sunlight to IBL enviroment (like with skydome)
if yes, why has it been removed ? and if no, then could this be added?
because i think, it would be good to have this option to support the sometimes soft shadows of HDRIs with a nice sun light (and shadows)
michael
Re: IBL with sunlight
Posted: Tue Jul 27, 2010 1:52 pm
by Mihai
You have to disable one of the IBL channels as always, and set "Use for disabled" to Physical Sky. Although with V2 you can get sharp shadows if the HDR shows the sun. You could also blur slightly the hdr map to change the aspect of the shadow.
Re: IBL with sunlight
Posted: Tue Jul 27, 2010 3:12 pm
by big K
thanks mihai for your reply.
yes, i know about the disabling, but this doesn´t allw me to set all to IBL (i want the relection, refraction, and also the illumination all with the HDRI) and still have a supporting sun. (which is possible with the sky dome)
of course i could add a tiny disc as a sun and do it manually, i just thought this is a good idea (thought it was possible already) as it is quite comfortable to setup.
Re: IBL with sunlight
Posted: Tue Jul 27, 2010 4:30 pm
by TZORG
I used to get (unwanted) sunlight with IBL but I'm not sure if I saw that since Maxwell 2...
Here is my thread on it
http://www.maxwellrender.com/forum/view ... =9&t=32348
Re: IBL with sunlight
Posted: Wed Aug 04, 2010 1:54 pm
by jc4d
big K wrote:thanks mihai for your reply.
...(i want the relection, refraction, and also the illumination all with the HDRI) and still have a supporting sun...
Would be nice to have it, is very usefull
Cheers
JC
Re: IBL with sunlight
Posted: Wed Aug 04, 2010 3:44 pm
by pipcleo
Being able to use physical sky with hdr illumination has one distinct advantage when using 'fake hdrs' made from standard panoramic photos.
These fake hdrs provide reflections, background and the correct illumination 'color' but their actual illumination is not up to standard , hence the
boost from physical sky covers this inadequacy.
See images below.
Without the physical sky these hdrs are unusable.
Would really like this feature implemented in 2.1 .....still need to return to 1.7.1 to do these specific renders
Uploaded with
ImageShack.us
Uploaded with
ImageShack.us
Re: IBL with sunlight
Posted: Wed Aug 04, 2010 4:47 pm
by rusteberg
pipcleo wrote:Being able to use physical sky with hdr illumination has one distinct advantage when using 'fake hdrs' made from standard panoramic photos.
These fake hdrs provide reflections, background and the correct illumination 'color' but their actual illumination is not up to standard , hence the
boost from physical sky covers this inadequacy.
wonderfully explained, pipcleo.
this is something i have missed from time to time with V2 as well.
it was a nice work around when using an hdr that would totally botch illumination when used solely, and would add just enough color to physical illumination as to not divorce the background from rendered geometry...
Re: IBL with sunlight
Posted: Thu Aug 05, 2010 2:33 am
by Bubbaloo
Can you not do this by defining a reflection, refraction and background hdr map, while leaving the illumination disabled, and set "use for disabled" to sunlight?
Re: IBL with sunlight
Posted: Thu Aug 05, 2010 5:27 am
by pipcleo
with that modus operandi the resulting render is totally different.
The color of the illumination from the hdr illumination channel is what is important.
With just the physical sky , the resulting renders dont have the correct color 'temp'...........too blue and/or cold
Re: IBL with sunlight
Posted: Thu Aug 05, 2010 5:39 am
by Bubbaloo
Another trick to use is to select a circle in the hdr in Photoshop where the sun is and overexpose it. It will make the sun brighter, and therefore make sharper shadows.
Re: IBL with sunlight
Posted: Thu Aug 05, 2010 7:31 am
by pipcleo
Brian , the reason I use this solution is that the 'fake hdr' is simply a standard panoramic photograph....
not up to the quality needed to provide full hdr illumination without ter sunlight boost.
Re: IBL with sunlight
Posted: Thu Aug 05, 2010 10:49 am
by Mihai
Just keep in mind though that if you use these kinds of fake hdr images, your reflections and refractions will suffer as well. They will just look dull and faded in windows and any reflective surfaces.
Another workaround is to first set the physical sky parameters so the sun falls where you want it, then render out an hdr map of the sky and blend that with your hdr in Photoshop or any image editor that can handle 32bit images and layers. Then you can just load this map in the illumination.
Re: IBL with sunlight
Posted: Thu Aug 05, 2010 2:51 pm
by pipcleo
Thanks Mihai...something to try
Problem here is that the pixel res of the fake hdrs wont match that of rendered hdr of the sky....
Why was this option removed from v2 ? and is there any reason why it cant be reinstated ?
Re: IBL with sunlight
Posted: Thu Aug 05, 2010 5:23 pm
by Mihai
Why wouldn't it match? You can render at the same rez as your illumination map. But I really wouldn't do it this way. I'd render an alpha and composite any background later.