Stephen <mcavoys_at@aoldotcom> wrote:

> lamp. The figure is supposed to be made of ivory.
> I know that the values for subsurface { <R,G,B>, <R,G,B>} should be

> Light Transport does not give any values for ivory. Does anyone have any
> ideas how to fudge them?
>
> Comments and ideas welcome.
>
> --
> Regards
>      Stephen

Steven, I'm working on an SSLT how-to for the wiki and translated the materials
chart from that SSLT paper into the following textures (so I could see what they
really look like in POV-Ray). Maybe this will help you fudge some values for
ivory...

/*
From "A Practical Model for Subsurface Light Transport", Jensen, et. al.
-------------------------------------------------------------------------------
Material     Scattering          Absorbing                  Color (diffuse refl)
-------------------------------------------------------------------------------
Apple      = <2.29, 2.39, 1.97>, <0.0030, 0.0034, 0.046>   : <0.85, 0.84, 0.53>
Chicken1   = <0.15, 0.21, 0.38>, <0.015, 0.077, 0.19>      : <0.31, 0.15, 0.10>
Chicken2   = <0.19, 0.25, 0.32>, <0.018, 0.088, 0.20>      : <0.32, 0.16, 0.10>
Cream      = <7.38, 5.47, 3.15>, <0.0002, 0.0028, 0.0163>  : <0.98, 0.90, 0.73>
Ketchup    = <0.18, 0.07, 0.03>, <0.061, 0.97, 1.45>       : <0.16, 0.01, 0.00>
Marble     = <2.19, 2.62, 3.00>, <0.0021, 0.0041, 0.0071>  : <0.83, 0.79, 0.75>
Potato     = <0.68, 0.70, 0.55>, <0.0024, 0.0090, 0.12>    : <0.77, 0.62, 0.21>
Skimmilk   = <0.70, 1.22, 1.90>, <0.0014, 0.0025, 0.0142>  : <0.81, 0.81, 0.69>
Skin1      = <0.74, 0.88, 1.01>, <0.032, 0.17, 0.48>       : <0.44, 0.22, 0.13>
Skin2      = <1.09, 1.59, 1.79>, <0.013, 0.070, 0.145>     : <0.63, 0.44, 0.34>
Spectralon = <11.6, 20.4, 14.9>, <0.00, 0.00, 0.00>        : <1.00, 1.00, 1.00>
Wholemilk  = <2.55, 3.21, 3.77>, <0.0011, 0.0024, 0.014>   : <0.91, 0.88, 0.76>
-------------------------------------------------------------------------------
*/

// components
#declare P_SSLT_Apple = pigment { rgb <0.85, 0.84, 0.53> }
#declare F_SSLT_Apple =
   finish { subsurface { <2.29, 2.39, 1.97>, <0.0030, 0.0034, 0.046> } }

#declare P_SSLT_Chicken1 = pigment { rgb <0.31, 0.15, 0.10> }
#declare F_SSLT_Chicken1 =
   finish { subsurface { <0.15, 0.21, 0.38>, <0.015, 0.077, 0.19> } }

#declare P_SSLT_Chicken2 = pigment { rgb <0.32, 0.16, 0.10> }
#declare F_SSLT_Chicken2 =
   finish { subsurface { <0.19, 0.25, 0.32>, <0.018, 0.088, 0.20> } }

#declare P_SSLT_Cream = pigment { rgb  <0.98, 0.90, 0.73> }
#declare F_SSLT_Cream =
   finish { subsurface { <7.38, 5.47, 3.15>, <0.0002, 0.0028, 0.0163> } }

#declare P_SSLT_Ketchup = pigment { rgb  <0.16, 0.01, 0.00> }
#declare F_SSLT_Ketchup =
   finish { subsurface { <0.18, 0.07, 0.03>, <0.061, 0.97, 1.45> } }

#declare P_SSLT_Marble = pigment { rgb <0.83, 0.79, 0.75> }
#declare F_SSLT_Marble =
   finish { subsurface { <2.19, 2.62, 3.00>, <0.0021, 0.0041, 0.0071> } }

#declare P_SSLT_Potato = pigment { rgb <0.77, 0.62, 0.21> }
#declare F_SSLT_Potato =
   finish { subsurface { <0.68, 0.70, 0.55>, <0.0024, 0.0090, 0.12>  } }

#declare P_SSLT_SkimMilk = pigment { rgb <0.81, 0.81, 0.69> }
#declare F_SSLT_SkimMilk =
   finish { subsurface {<0.70, 1.22, 1.90>, <0.0014, 0.0025, 0.0142> } }

#declare P_SSLT_Skin1 = pigment { rgb <0.44, 0.22, 0.13> }
#declare F_SSLT_Skin1 =
   finish { subsurface { <0.74, 0.88, 1.01>, <0.032, 0.17, 0.48> } }

#declare P_SSLT_Skin2 = pigment { rgb <0.63, 0.44, 0.34> }
#declare F_SSLT_Skin2 =
   finish { subsurface { <1.09, 1.59, 1.79>, <0.013, 0.070, 0.145> } }

#declare P_SSLT_Spectralon = pigment { rgb <1.00, 1.00, 1.00> }
#declare F_SSLT_Spectralon =
   finish { subsurface { <11.6, 20.4, 14.9>, <0.00, 0.00, 0.00> } }

#declare P_SSLT_Wholemilk = pigment { rgb <0.91, 0.88, 0.76> }
#declare F_SSLT_Wholemilk =
   finish { subsurface { <2.55, 3.21, 3.77>, <0.0011, 0.0024, 0.014> } }

// SSLT base textures
#declare T_SSLT_Apple = texture {
   pigment { P_SSLT_Apple }
   finish { F_SSLT_Apple }
}

#declare T_SSLT_Chicken1 = texture {
   pigment { P_SSLT_Chicken1 }
   finish { F_SSLT_Chicken1 }
}

#declare T_SSLT_Chicken2 = texture {
   pigment { P_SSLT_Chicken2 }
   finish { F_SSLT_Chicken2 }
}

#declare T_SSLT_Cream = texture {
   pigment { P_SSLT_Cream }
   finish { F_SSLT_Cream }
}

#declare T_SSLT_Ketchup = texture {
   pigment { P_SSLT_Ketchup }
   finish { F_SSLT_Ketchup }
}

#declare T_SSLT_Marble = texture {
   pigment { P_SSLT_Marble }
   finish { F_SSLT_Marble }
}

#declare T_SSLT_Potato = texture {
   pigment { P_SSLT_Potato }
   finish { F_SSLT_Potato }
}

#declare T_SSLT_SkimMilk = texture {
   pigment { P_SSLT_SkimMilk }
   finish { F_SSLT_SkimMilk }
}

#declare T_SSLT_Skin1 = texture {
   pigment { P_SSLT_Skin1 }
   finish { F_SSLT_Skin1 }
}

#declare T_SSLT_Skin2 = texture {
   pigment { P_SSLT_Skin2 }
   finish { F_SSLT_Skin2 }
}

#declare T_SSLT_Spectralon = texture {
   pigment { P_SSLT_Spectralon }
   finish { F_SSLT_Spectralon }
}

#declare T_SSLT_Wholemilk = texture {
   pigment { P_SSLT_Wholemilk }
   finish { F_SSLT_Wholemilk }
}

-------------------------------------------------
www.McGregorFineArt.com

Post a reply to this message

Attachments:
Download 'sslt_textures.png' (247 KB)

Preview of image 'sslt_textures.png'