// Last edited on 2022-07-24 00:32:32 by stolfi

#macro camera_parameters(thing, clk) 
  // Globally defines the {camlight} parameters {scene_center},
  // {scene_radius}, {dir_camera}, and {dist_camera} for the view of
  // object {thing} for the movie clock {clk}.
  
  #local thpos = min_extent(thing);
  #local thdim = max_extent(thing) - thpos;
  #debug concat("\n!! thpos = ", vstr(3, thpos, " ", 0,1), "  thdim = ", vstr(3, thdim, " ", 0,1), "\n")
  #local thrad = vlength(thdim)/2;
  #local thctr = thpos + thdim/2;
  
  #local azim = 4*pi*clk;
  #local elev = 0.5*pi*(0.20 - 0.15*cos(0.5*azim));
  
  #declare scene_center = thctr;
  #declare scene_radius = 1.5*thrad;
  #declare dir_camera = < cos(azim)*cos(elev), sin(azim)*cos(elev), sin(elev) >;
  #declare dist_camera = 5*scene_radius;
#end