[x3d-public] Bad Equation in 4.0 clean version

[Brutzman, Donald (Don) (CIV)]

Thanks for noting this problem Dick.

 

Michalis, can you please confirm that these equations are expressed
correctly:

 

*	X3D4 Architecture, 12 Shape component, 12.4.6 PhysicalMaterial
*
https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/
components/shape.html#PhysicalMaterial 
*	(then scroll down, copy follows)

 

The following equations show how to calculate bidirectional reflectance
distribution function (BRDF) inputs (cdiff, F0, "α ) from the
metallic-roughness material properties.

const dielectricSpecular = rgb(0.04, 0.04, 0.04)

const black = rgb(0, 0, 0)

cdiff = lerp(baseParameter * (1 - dielectricSpecular.r), black,
metallicParameter)

F0 = lerp(dieletricSpecular, baseParameter, metallicParameter)

α = roughnessParameter ^ 2

 

 

all the best, Don

-- 

Don Brutzman  Naval Postgraduate School, Code USW/Br        brutzman at nps.edu

Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA    +1.831.656.2149

X3D graphics, virtual worlds, Navy robotics https://
faculty.nps.edu/brutzman

 

From: Richard Puk <puk at igraphics.com> 
Sent: Friday, May 27, 2022 8:46 AM
To: Brutzman, Donald (Don) (CIV) <brutzman at nps.edu>
Subject: Bad Equation in 4.0 clean version

 

NPS WARNING: *external sender* verify before acting.

 

Hi, Don -

 

This is the requested e-mail listing the bad equation at the end of 12.4.6
PhysicalMaterial.

 

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