Documentation/figures/4S+2D_reciproque2.pov

   1 #include "colors.inc"    // The include files contain
   2 #include "textures.inc"  // pre-defined scene elements
   3 #include "glass.inc"
   4 #include "metals.inc"
   5 #include "skies.inc"
   6 #include "shapes.inc"
   7 #include "bravais.inc"
   8 #include "arrows.inc"
   9
  10 // les vecteurs du cristal
  11 #declare a = <1,0,0>;
  12 #declare b = <.31,.95,0>;
  13 #declare c = <.4,.5,0.76>;
  14
  15 #declare camera_location = 5 * (x+y+.5*z)+ 3*z + y;
  16 #declare camera_look_at = <0,0,0>+3*z + y;
  17
  18 //#declare camera_location = a/2+b/1.5-2*z;
  19 //#declare camera_look_at = a/2+b/1.5;
  20
  21 global_settings{ max_trace_level 255 }
  22
  23 background { color DarkGreen }
  24
  25 // all setup
  26 camera {
  27   orthographic
  28   location camera_location
  29   look_at camera_look_at
  30 }
  31
  32 light_source {
  33         <10, 0, 0>
  34         color White
  35         parallel
  36         point_at <0, 0, 0>
  37         shadowless
  38 }
  39 light_source {
  40         <0, 10, 0>
  41         color White
  42         parallel
  43         point_at <0, 0, 0>
  44 }
  45 light_source {
  46         <0, 0, 10>
  47         color White
  48         parallel
  49         point_at <0, 0, 0>
  50 }
  51
  52 union{
  53   plane { <1,0,0>, -3 pigment {color LightWood} }
  54   plane { <0,1,0>, 0 pigment {color LightWood*.9 transmit .3} }
  55   plane { <0,0,1>, 0 pigment {color LightWood*.8}}
  56 }
  57
  58 // Les trois directions principales
  59 cylinder{<0,0,-10>,<0,0,10>, .01 pigment {color Grey}}
  60 cylinder{<0,-10,0>,<0,10,0>, .01 pigment {color Grey}}
  61 cylinder{<-10,0,0>,<10,0,0>, .01 pigment {color Grey}}
  62
  63 // La construction d'Ewald
  64 #macro ewald(ki, gamma, delta, Alpha, phi)
  65   #local kf = vrotate(vrotate(ki, delta*x), -gamma*y);
  66   #local Q = kf-ki;
  67   #local n = vrotate(vrotate( vlength(Q)*x, Alpha*y), phi*z);
  68   #local nq = vnormalize(Q);
  69   // normale au plan de diffraction
  70   #local ns = vnormalize(vcross(ki, Q));
  71
  72   // Vecteurs incident et diffracté
  73   union{
  74     arrow(ki, Blue)
  75     arrow(kf, Green)
  76
  77     translate -ki
  78   }
  79   // Vecteur de diffraction
  80   arrow(Q, Red)
  81
  82   // angle vartheta
  83   object{sector(x, n.x*x+n.y*y, Firebrick, 1)}
  84
  85   // angle theta
  86   object{sector(n, n.x*x+n.y*y, OrangeRed, .5) no_shadow}
  87
  88   object{arrow(n, Yellow)}
  89
  90   // sphères d'ewald
  91   merge{
  92     sphere{-ki, vlength(ki) pigment {color Green transmit .93}}
  93     no_shadow
  94   }
  95 #end
  96
  97 ewald(-3*z, -30, 40, -60, 30)
  98
  99 // Repère orthonormé de la ligne cristal de soleil.
 100 object{repere_soleil translate 7.5*z no_shadow}