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, -0.5, 0)
  21     local distance  = 4
  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 p 0.0 -5.0 0.0 0.0 1.0 0.0 0.4 0.8 0.4
  39 s 0.0 0.0 0.0 1.25 1.0 0.0 0.0
  40 s -1.0 -1.0 0.0 1.0 0.0 1.0 0.0
  41 s 1.0 -1.0 0.0 1.0 0.0 0.0 1.0
  42 t -1.5 0.0 1.5 -1.0 1.0 0.0 -0.5 0.0 1.5 0.8 0.9 0.2
  43 t 1.5 0.0 1.5 1.0 1.0 0.0 0.5 0.0 1.5 0.2 0.9 0.8
  44 ]]
  45
  46 -- Set the number of samples for supersampling.  If this is set to a value
  47 -- of two or greater, each frame will be rendered larger by the factor
  48 -- specified.  ImageMagick is used to scale the frames back down to size;
  49 -- if ImageMagick is not installed, this script will exit with error 1.
  50 local supersample = 2
  51
  52 -- Set the width and height of the viewport.
  53 local size = {w = 800, h = 600}
  54
  55 -- Set the number of concurrent renderings (for multi-core machines).
  56 local jobs = 6
  57
  58 -- Set the options to be passed directly to ffmpeg.
  59 local ffmpeg_opts = "-b 1024k"
  60
  61 -- end of configuration
  62 ---------------------------------------------------------------------------
  63
  64 function vec_new(x, y, z)
  65     return {x = x, y = y, z = z}
  66 end
  67
  68 function vec_add(a, b)
  69     return vec_new(a.x + b.x, a.y + b.y, a.z + b.z)
  70 end
  71
  72 function vec_scale(v, s)
  73     return vec_new(v.x * s, v.y * s, v.z * s)
  74 end
  75
  76 local fmt   = string.format
  77 local write = function(...) io.write(fmt(...)) io.flush() end
  78 local run   = function(...) return os.execute(fmt(...)) end
  79
  80 function render(i)
  81     while i do
  82         local w, h = size.w, size.h
  83         if 1 < supersample then
  84             w = w * supersample
  85             h = h * supersample
  86         end
  87         local filename  = fmt("frames/anim%04d.bmp", i)
  88         local command   = fmt("./raytrace -o %s >/dev/null", filename)
  89         local out = io.popen(command, "w")
  90         local e = eye(i)
  91         local l = look(i)
  92         write("\27[80D\27[2Kframe\t %4d / %d", i, frames)
  93         out:write(fmt([[
  94 U5
  95 %d %d
  96 %f %f %f
  97 %f %f %f
  98 0 1 0
  99 1.57 %f
 100 0.4 0.4 0.4
 101 %s
 102 X
 103 ]], w, h, e.x, e.y, e.z, l.x, l.y, l.z, size.w/size.h, scene))
 104         i = coroutine.yield()
 105         out:close()
 106         if 1 < supersample and
 107                 run("convert %s -scale %dx%d %s", filename, size.w, size.h, filename) ~= 0 then
 108             print()
 109             os.exit(1)
 110         end
 111     end
 112 end
 113
 114 function renderings()
 115     local t = {}
 116     for i = 1,jobs do
 117         table.insert(t, coroutine.wrap(render))
 118     end
 119     local iterations = frames + jobs
 120     local frame = 0
 121     return function()
 122         frame = frame + 1
 123         if frame <= iterations then
 124             local i = frame
 125             if frames < i then i = null end
 126             return t[1 + frame % jobs], i
 127         end
 128     end
 129 end
 130
 131 print("Animating scene...")
 132
 133 run("rm -rf frames && mkdir frames >/dev/null 2>&1")
 134 for render,frame in renderings() do render(frame) end
 135
 136 print()
 137
 138 if run("ffmpeg -i frames/anim%%04d.bmp %s -y -an scene.avi", ffmpeg_opts) == 0 then
 139     print("Animation written to scene.avi.")
 140 else
 141     print("The animation could not be created. Is ffmpeg installed?")
 142     os.exit(2)
 143 end
 144