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**General Discussion / Re: The albedo question.**

« **on:**2014-03-16, 05:48:56 »

Great to hear that, i'm gonna try to understand the way Corona material works... to really understand and avoid the always neccesary "cheat".

This article is a little heavy but maybe helps me understand the basics.

http://www.scratchapixel.com/lessons/3d-advanced-lessons/things-to-know-about-the-cg-lighting-pipeline/what-is-a-brdf/

If i remember correctly 3ds max design uses some ligthing analysis that where expressed in pretty solid S.I. units (not parrots) but only for MentalRay using some Brute force aproach (unbiased?).

So i have no doubt that tuning a Corona Material we can set that LRV values at least for a solid color... the question is how.

For example 10 boxes and 10 ligths one base plane.

Default Corona White material (180 rgb white).

1.- Change "value" in diffuse (reflection, refraction 0) gives expected results.

2.- Change "color" in difusse (reflection, refraction 0) gives expected results.

3.- Change "value" in reflection (diffuse, refraction 0) gives no ligth on ground.

4.- Change "color" in reflection (diffuse, refraction 0) gives no ligth on ground.

Interesting topic the reflectance you where rigth about that 90° aproach... but here comes the fresnel to save the day.

I really need to understand the way brdf shader work.

This article is a little heavy but maybe helps me understand the basics.

http://www.scratchapixel.com/lessons/3d-advanced-lessons/things-to-know-about-the-cg-lighting-pipeline/what-is-a-brdf/

If i remember correctly 3ds max design uses some ligthing analysis that where expressed in pretty solid S.I. units (not parrots) but only for MentalRay using some Brute force aproach (unbiased?).

So i have no doubt that tuning a Corona Material we can set that LRV values at least for a solid color... the question is how.

For example 10 boxes and 10 ligths one base plane.

Default Corona White material (180 rgb white).

1.- Change "value" in diffuse (reflection, refraction 0) gives expected results.

2.- Change "color" in difusse (reflection, refraction 0) gives expected results.

3.- Change "value" in reflection (diffuse, refraction 0) gives no ligth on ground.

4.- Change "color" in reflection (diffuse, refraction 0) gives no ligth on ground.

Interesting topic the reflectance you where rigth about that 90° aproach... but here comes the fresnel to save the day.

I really need to understand the way brdf shader work.