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   Convert Matlab color parameters to obj parameters
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   Form:
   [Ns, d, illum, Kd, Ks, Ka] = MatlabColorToObj( faceColor, specularStrength,
   specularExponent, diffuseStrength, specularColorReflectance )
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   Inputs
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   faceColor                (1,3) Face color
   specularStrength         (1,1) Specular strength
   specularExponent         (1,1) Specular exponent
   diffuseStrength          (1,1) Diffuse exponent
   specularColorReflectance (1,1) Specular color reflectance

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   Outputs
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   Ns                       (1,1) Shininess 10 = 91