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rdg
08-09-2006, 09:23 AM
Hello,

I try to get some lighting as the samples on HDRI-Studio: (http://www.hdri-studio.com/N011.html). Befor investing in some of their files, I wanted to test the technique.

I dont get anything like the reference.
Basic workflow:

HDRI as bitmap (from the maps directory of max)
set black and white point (so no clamps are visible in the preview
whitepoint value as RGB Level
bitmap type to spherical environment
Bitmap as instance in skylight map slot
Mentral Ray with Final Gather rendering
The image is far too dark, if i crank up the skilight multiplier to something like 20 the image get brighter, but nothing like differenciated shadows ....

The attached file is MAX8SP3 and uses a hdr file from the max maps directory desk_sm_blurry .
I tried both the low and the high versions.

I searched the forums but I don't get it.

Maybe someone can take a look at my file, or tell me how to change the settings?
Or even post an image that was uses a max-sample hdri as the only light source and has cool shadows ... ?

thank you

Georg

3DMadness
08-09-2006, 08:58 PM
I took a look at your scene, basically I scaled the white point a bit higher, the linear I put 6 and this same value to the RGB level and the scene got not so darker than it was. But this HDR file is not so bright, so the scene will be dark. You can still put a higher value in the RGB level or increase the skylight multiplier. To get better shadows with HDR you have to increase the finalgather samples, but you need a brigheter HDR imagem to have a brighter scene. ;)

Dashkevicz
08-09-2006, 11:55 PM
yeah, 3DMadness is right this hdr dosn't lend itself to creating shadows. I tried this one and got some nice results: Loft_Lights_Sm_Blurry.hdr on this note...(and I'm just think out loud) mabe cliping the image's black point and raising the skylight's multiplier might work. It would cut out the "ambient light" your getting from the rest of the image and allow you to raise the multiplier.

rdg
08-10-2006, 10:07 AM
3DMadness + Dashkevicz,

Thanks for your investigation.

So I have to 'play' a little more with the settings and take a look at different HDR-files to get a feeling for this technique.

I didn't know that it is 'ok' to rise the skylight multiplier.
I forgot the saying from Gary Yost:
"If it looks right - it is right".

Now I will go to holidays. So there will be no replies for the next two weeks.

Thanks again.

Georg

rdg
11-28-2006, 08:23 AM
the HDRI-Studio files and vray poduced the lighting I was looking far.
Georg

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