MR : Maya Lafortune Shader


#1

The Lafortune shader is based on the renderman shader by Stephen H. Westin and the research paper Non-linear approximation of reflectance functions. The shader introduces a new class of primitive functions with non-linear parameters for representing light reflectance functions. The functions are reciprocal, energy-conserving and expressive. They can capture important phenomena such as off-specular reflection, increasing re-flectance and retro-reflection.

Lafortune Shader
Os: NT/2000/XP
Maya Version: 4.0 / 4.5 / 5.0 / 6.0
:Mental Ray Version included:


#2

Linux? I can do compiles if needed.


#3

Let him compile !!! :smiley: Thanks for the shader :slight_smile:


#4

:slight_smile: Hey jackDeth when i go that route i’ll make sure to hit you up, No Prob Dr. Ira Kane hope the shader is usefull.


#5

I’m curious what sort of materials this is best suited for?

_Mike


#6

Hey mike I know from looking at the Sphere render there it really doesn’t look interesting, but the whole reason i’ve even bother for this shader was that it comes with 2 data sets of actual measured human reflectance data. which in the presets are “caucasianMale” “indianMale” or in MR shader its specoutput “5” and “6” if one had the proper studio you could measure the reflectance data of any material in the world and apply those into the shader. really its a 27 controllable coffients in the shader but i’ve block these from the user since it would be pointless to just randomly input numbers and hope to get nice results. So i just put 7 famous defaults in to the shader, which are bluePaint, grayPrimer, redClay, blackFelt, blueFelt, caucasianMale, and indianMale. But mainly the shader is an extremely fancy 3 blinn shader which works from the measured data inputed into. So back to the skin specular reason I first mention up top, a simple image looks decent esp for skin but when your doing an animtion or the light moves the specular reflectance acts like that object so for skin you’ll notice that at the glancing angles you’ll get the proper results like real skin spec. With out having to come with a whole network of specular’s to capture that effect, It will capture the higher spec at glancing angles and capture the color change in the specular color, even captures how skin anisotropic in certain areas. Pheeewwww well i hope with all that said i hope you can find some use for it like i have.

these are 2 test renders of a skin shader i’ve been working that have my own SSS effects and own specular components plus the lafortune specular to capture a more realistic specular component.



#7

Now do you see the love-fest you get from making MR shaders? Now just imagine that times ten once you develop for Linux. Your feet won’t touch the ground for a week, if you know what I mean. :wink:


#8

:slight_smile:

Hey jackDeth when i go that route i’ll make sure to hit you up

Hope this is soon, the worst OS in the world always gets the good stuff first, go figure :smiley:

MunCH


#9

thats really very good, thank you


#10

:eek: I was wondering why i started to hover off the floor the other day :smiley: Ok Ok OK i have to admit that developing shaders in MR is much better than in Maya so many nice functions to call and use heck maybe now i can implement a BSSRDF shader since iam not as limited. But Iam gonna see about porting to linux. Thanks dudders hope you enjoy. :slight_smile:


#11

Is it possible to use the Lafortune Shader speculars over the miss fast shaders.
Been trying without much success.


#12

Iam not to familiar with mental ray totally but iam pretty sure that you should be able to layer it over the Miss shader.


#13

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