Dogcows Code - chaz/rasterize/blob - animate.lua

   1 #!/usr/bin/env lua
   2
   3 --
   4 -- CS5600 University of Utah
   5 -- Charles McGarvey
   6 -- mcgarvey@eng.utah.edu
   7 --
   8
   9 -- This program automates the process of creating simple fly-by animations.
  10 -- The rasters are saved in the `frames' directory, and if ffmpeg is
  11 -- installed, the frames will also be combined into a video file.  This script
  12 -- must be called from the same directory where the raytrace program is.
  13
  14 -- Set the number of frames to be rendered for the animation.
  15 local frames = 360
  16
  17 -- Define the code to calculate where the camera is, in world coordinates.
  18 local eye = function(frame)
  19     -- just rotate around the center of the scene on the XZ plane
  20     local center    = vec_new(0, 0.4, 0)
  21     local distance  = 0.7
  22     local start     = math.pi
  23     local t = start + 2 * math.pi * frame / frames
  24     local v = vec_new(math.cos(t), 0, math.sin(t))
  25     return vec_add(vec_scale(v, distance), center)
  26 end
  27
  28 -- Define the code to calculate where the focal point of the scene is.
  29 local look = function(frame)
  30     -- keep the camera focused at the center
  31     return vec_new(0, 0, 0)
  32 end
  33
  34 -- Define the actual objects of the scene that will be rendered, in the
  35 -- extended urt format.
  36 local scene = [[
  37 l 0.0 10.0 1.0 0.8 0.7 0.8
  38 s 0.0 0.0 0.0 1.0 1.0 0.0 0.0
  39 ]]
  40
  41 -- Set the number of samples for supersampling.  If this is set to a value
  42 -- of two or greater, each frame will be rendered larger by the factor
  43 -- specified.  ImageMagick is used to scale the frames back down to size;
  44 -- if ImageMagick is not installed, this script will exit with error 1.
  45 local supersample = 2
  46
  47 -- Set the width and height of the viewport.
  48 local size = {w = 800, h = 600}
  49
  50 -- Set the number of concurrent renderings (for multi-core machines).
  51 local jobs = 6
  52
  53 -- Set the options to be passed directly to ffmpeg.
  54 local ffmpeg_opts = "-b 1024k"
  55
  56 -- end of configuration
  57 ---------------------------------------------------------------------------
  58
  59 function vec_new(x, y, z)
  60     return {x = x, y = y, z = z}
  61 end
  62
  63 function vec_add(a, b)
  64     return vec_new(a.x + b.x, a.y + b.y, a.z + b.z)
  65 end
  66
  67 function vec_scale(v, s)
  68     return vec_new(v.x * s, v.y * s, v.z * s)
  69 end
  70
  71 local fmt   = string.format
  72 local write = function(...) io.write(fmt(...)) io.flush() end
  73 local run   = function(...) return os.execute(fmt(...)) end
  74
  75 function render(i)
  76     while i do
  77         local w, h = size.w, size.h
  78         if 1 < supersample then
  79             w = w * supersample
  80             h = h * supersample
  81         end
  82         local filename  = fmt("frames/anim%04d.bmp", i)
  83         local command   = fmt("./raytrace -o %s >/dev/null", filename)
  84         local out = io.popen(command, "w")
  85         local e = eye(i)
  86         local l = look(i)
  87         write("\27[80D\27[2Kframe\t %4d / %d", i, frames)
  88         out:write(fmt([[
  89 U5
  90 %d %d
  91 %f %f %f
  92 %f %f %f
  93 0 1 0
  94 1.57 %f
  95 1.0 1.0 1.0
  96 %s
  97 X
  98 ]], w, h, e.x, e.y, e.z, l.x, l.y, l.z, size.w/size.h, scene))
  99         i = coroutine.yield()
 100         out:close()
 101         if 1 < supersample and
 102                 run("convert %s -scale %dx%d %s", filename, size.w, size.h, filename) ~= 0 then
 103             print()
 104             os.exit(1)
 105         end
 106     end
 107 end
 108
 109 function renderings()
 110     local t = {}
 111     for i = 1,jobs do
 112         table.insert(t, coroutine.wrap(render))
 113     end
 114     local iterations = frames + jobs
 115     local frame = 0
 116     return function()
 117         frame = frame + 1
 118         if frame <= iterations then
 119             local i = frame
 120             if frames < i then i = null end
 121             return t[1 + frame % jobs], i
 122         end
 123     end
 124 end
 125
 126 print("Animating scene...")
 127
 128 run("rm -rf frames && mkdir frames >/dev/null 2>&1")
 129 for render,frame in renderings() do render(frame) end
 130
 131 print()
 132
 133 if run("ffmpeg -i frames/anim%%04d.bmp %s -y -an scene.avi", ffmpeg_opts) == 0 then
 134     print("Animation written to scene.avi.")
 135 else
 136     print("The animation could not be created. Is ffmpeg installed?")
 137     os.exit(2)
 138 end
 139