"Kenneth" <kdw### [at] gmailcom> wrote:
> "kmcpeak" <kmc### [at] ethzch> wrote:
>
> >
> > I used a transform to bring the top of the silicon surface to y = 0. This
> > helped me figure out the pigment_map. Attached is my latest effort. I think
> > I need to move the lights a bit but overall this is way way better than
> > where I started.
>
> Hey, that's looking *much* better.
>
> I think (as you say) that the light positions are still not quite right. It
> looks like they are 'diagonal' to the object, and still too close to it. In my
> own tests, those light positions turned out to be rather critical, to change the
> 'bumps' into 'indents.' Try placing them exactly left-and-right to the object,
> really far away, and maybe lower in y(?). (And no fade-power, of course.) With
> some more experimentation, you'll probably find the 'sweet spot' for those
> lights.

After some movement of the lights and adding bumps to the etch pits attached is
my latest best effort. Might stop here... Code below:

#declare Tex_Silicon =
texture{
   pigment{
      gradient y
      pigment_map{
           [0.01 // For the top surface only
           average
           pigment_map{
              [1 rgb 0.3]
              [1.25 bumps scale .0005]
                      }
           ]
           [0.01       // immediately under the surface
           average
           pigment_map{
              [1 rgb 0.7]
              [0.5 bumps scale .0005]
                      }
           ]
           [0.8     // for the indents
           average
           pigment_map{
              [1 rgb 0.5]
              [0.5 bumps scale .0005]
                      }
           ]
                 }
           scale 1.65*<1,-1,1> // Adjust the multiplier so
// the bottom of your SEM indents don't start showing the repeating
// gradient y pattern. The -1 for y just 'flips' the gradient y, as
// I specified the colors going 'up', not down.
         }
   finish{ambient 0.1 diffuse 1} // You might want to add a little bit of
ambient.
       }

#declare Material_0=material{
texture {Tex_Silicon }
 }


camera {
   location <0.00000, 55, 0.000000> // <up/down, height, right/left>
   look_at <0.000000, 0.000000, 0.000000>
   right x*image_width/image_height
   //up <0,0,1>
   rotate  <0, 90, 0>
}


// The lights...
// Top left
light_source {
  <0, 0, 0>
  color rgb .7
  area_light
  <20, 0, 0> <0, 40, 0> // lights spread out across this distance (x * z)
  8, 8                // total number of lights in grid (4x*4z = 16 lights)
  adaptive 0          // 0,1,2,3...
  jitter              // adds random softening of light
  circular            // make the shape of the light circular
  orient              // orient light
  translate <50, 20, 80> // <+up/-down, +height, -right/+left>
}


// Right middle
light_source {
  <0, 0, 0>
  color rgb .9
  area_light
  <0, 0, 0> <10, 30, 0> // lights spread out across this distance (x * z)
  8, 8                // total number of lights in grid (4x*4z = 16 lights)
  adaptive 0          // 0,1,2,3...
  jitter              // adds random softening of light
  circular            // make the shape of the light circular
  orient              // orient light
  translate <10, 35, -60> // <+up/-down, +height, -right/+left>
}

// Top
light_source {
  <0, 0, 0>
  color rgb .2
  area_light
  <0, 0, 0> <30, 0, 30> // lights spread out across this distance (x * z)
  8, 8                // total number of lights in grid (4x*4z = 16 lights)
  adaptive 0          // 0,1,2,3...
  jitter              // adds random softening of light
  circular            // make the shape of the light circular
  orient              // orient light
  translate <0, 50, 0> // <+up/-down, +height, -right/+left>
}

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