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thorsten hartmann
10-25-2010, 01:14 PM
Hi Guys,

i have write a Tutorial for IBL-Rendering with mental ray. Autodesk have forget to set the correct "Light Mode" Value for IBL-Rendering. Please Download the newest Update of Shader Utilities and it is fixed. The A&D Material donīt work at this time, and we say to Autodesk a big:"Thank you!", but you can use equivalent the TH-Generic Material.

Tutorial (de): http://www.infinity-vision.de/ShaderUtilities/de/su_ibl.htm

Tutorial (eng): http://www.infinity-vision.de/ShaderUtilities/eng/su_ibl.htm

Edit: The IBL-Script is at the new Shader Utilities Paket included.

http://www.infinity-vision.de/ShaderUtilities/Tutorial_ibl/ibl_test_outdoor_small.JPG

have fun!

mfg
hot chip

Bullit
11-01-2010, 02:40 AM
Thanks.
Those blotches in car surface are because of IBL?

thorsten hartmann
11-01-2010, 09:45 AM
Hi Bullit,


No, IBL is correct. It is the CarPaint. I have use a Camoflage Texture.

mfg
hot chip

Bullit
11-02-2010, 12:40 AM
Okay. Thanks.

I have 2 problems about an IBL issue maybe you can help.

In a background with a road a part of it is shaded by a tree. But the sun passes trough various leaves/branches so there are parts with sunlight and other parts in shade.

Question1: When a car passes over that part of the road it should shade the ground under it equal but the matte shadow object as far as i know can't add a light shadow to already shaded area of the photo and add at same time a strong shadow to the sun-lighted parts of the road. So under the car the matte shadow object still shows the sun-lighted parts.


Question2: A car going trough shadow and sunlight will make soft shadows in first and hard shadows in second. What is the best way to handle this? Area light?

thorsten hartmann
11-02-2010, 03:10 PM
Hi bullit,

A) yes this is a problem. But you can put a Tree at the scene, to create the Shadows. I use the Matte/Shadow/reflection Material on the Tree.

b) yes Area-Light are the best Solution. IBL-Lighting and a "good HDRI" with more as 10 exposures, give you a good lightsimulation. The most HDRI-Reseller have only 6 or 5 Exposures and the dynamic at HDRI is too low.

mfg
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Bullit
11-02-2010, 08:05 PM
Thanks for de 2nd advice.

Concerning first question maybe i didn't explained correctly. The problem is the shadows of the car in the ground plane. The ground plane image - note this is the image background matte object- has by itself parts illuminated and parts in shadow. Since the car goes over it the illuminated parts of the image background should be shaded too not dissimilar to the already shaded parts(by the tree). So the car should add much more shadow to the iluminated parts of image background than to the shaded parts of image background. Maybe with Mentalray nodes can be extracted the luminance and then add more shadow intensity to the higher luminance areas and add less shadow to already shadowed parts of the ground matte object., unfortunately i am not very advanced in Mentalray learning.

thorsten hartmann
11-03-2010, 12:20 AM
ah i hope i understand. The double Shadow Effects of Car (virtuell Shadow) + Tree (real Shadow) in the road. Yes this is a problem. You can adjust the brightness of shadow color. Better is a AO+Shadow Pass and then mixed at the video post at the matte/shadow/reflection" Shader. The Images ares Beauty-Rendering without postprocessing.

Bullit
11-04-2010, 06:00 AM
Yes correct. Thanks.

thorsten hartmann
11-04-2010, 06:42 AM
Hi Bullit,

here the Golf Car in Silver. I hope it looks better and no Camoflage Texture.

http://www.infinity-vision.de/service/car_silver.JPG

mfg
hot chip

Bullit
11-05-2010, 04:09 AM
After my brain shifted for camouflage paint :) it was all okay.

thorsten hartmann
11-15-2010, 10:07 AM
Hi Guys,

i have update SU and inlcuded a A&D to TH-Generic Converter. Now you can convert a hole Scene for IBL-Rendering.

http://www.infinity-vision.de/ShaderUtilities/Tutorial_ibl/su_pro_a&d_konverter.JPG

have fun!

mfg
hot chip

thorsten hartmann
11-22-2010, 07:13 AM
Hi Guys,

it give a update of my IBL-Tutorial with more information, diagramm and examples. How works Gamma Correction, Light intensity and Shadow sharpness.

http://www.infinity-vision.de/ShaderUtilities/eng/su_ibl.htm

have fun!

http://www.infinity-vision.de/ShaderUtilities/Tutorial_ibl/su_ibl_titel.JPG

mfg
hot chip

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