X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Frasterize;a=blobdiff_plain;f=animate.lua;h=b9fb1be73c995bf31013172f8e2bcceac4e7e4bd;hp=d04f5df539a98bd00bbad77de0ee65c495d5bee3;hb=09dd89d10e65029f0be313dd463ba1f43cac2fbb;hpb=e16cf0578f4baaf879e4ab9d3528a765bfd29be0

diff --git a/animate.lua b/animate.lua
index d04f5df..b9fb1be 100755
--- a/animate.lua
+++ b/animate.lua
@@ -6,32 +6,41 @@
 -- mcgarvey@eng.utah.edu
 --
 
--- This program that draws a scene multiple times from different camera angles
--- and positions.  The rasters are saved in the `frames' directory, and if
--- ffmpeg is installed, they will also be combined into a video file.  The
--- camera will make a full rotation along the X and Z axes, around a specified
--- point (center), all the while looking at some other point (look).
--- This must be called from the same directory where the rasterize program is.
-
-local size      = {w = 640, h = 480}    -- width and height of the viewport
-local frames    = 512                   -- number of animation frames
-
-local look      = {x = 2, y = 1, z = 2} -- the point to look at
-local center    = {x = 0, y = 1, z = 0} -- center of rotation
-local distance  = 4                     -- the distance from the center
-local start     = math.pi               -- where is the first frame
+-- This program automates the process of creating simple fly-by animations.
+-- The rasters are saved in the `frames' directory, and if ffmpeg is
+-- installed, the frames will also be combined into a video file.  This script
+-- must be called from the same directory where the rasterize program is.
+
+-- Set the number of frames to be rendered for the animation.
+local frames = 360
+
+-- Define the code to calculate where the camera is, in world coordinates.
+local eye = function(frame)
+    -- just rotate around the center of the scene on the XZ plane
+    local center    = vec_new(0, 1, 0)
+    local distance  = 4
+    local start     = math.pi
+    local t = start + 2 * math.pi * frame / frames
+    local v = vec_new(math.cos(t), 0, math.sin(t))
+    return vec_add(vec_scale(v, distance), center)
+end
 
-local jobs      = 6                     -- number of concurrent renderings
+-- Define the code to calculate where the focal point of the scene is.
+local look = function(frame)
+    -- keep the camera focused on the buddha
+    return vec_new(2, 1, 2)
+end
 
--- the actual objects of the scene that will be drawn:
+-- Define the actual objects of the scene that will be rendered, in the
+-- extended u3d format.
 local scene = [[
 L 0 1000000 0 1 1 1 1 1 1
 L 0 0 1000000 1 1 1 1 1 1
-g triangle.raw
-c 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1
-t 2 0 -2
-s 1 1 1
+g ak47.obj
+c 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
+M 0.9 0.9 0.9 128
 g dragon.raw
+M 0.3 0.3 0.3 5
 c 0.7 0.3 0.2 0.8 0.2 0.1 0.9 0.2 0.2
 t -2 -1 -2
 s 2 2 2
@@ -40,32 +49,57 @@ c 0.1 0.2 0.7 0.1 0.3 0.9 0.2 0.1 0.8
 t 2 -1.5 2
 s 10 10 10
 g bunny.raw
+M 0.2 0.2 0.2 1
 c 0.9 0.8 0.9 0.8 0.7 0.9 0.9 0.8 0.7
 t -2 -1 2
 s 10 10 10
-g teapot2.raw
-c 0 1 0 0 1 0 0 1 0
-t 0 -1 0
-s 0.6 0.6 0.6
 ]]
 
+-- Set the number of samples for supersampling.  If this is set to a value of
+-- two or greater, each frame will be rendered larger by the factor specified.
+-- ImageMagick is used to scale the frames back down to size; if ImageMagick
+-- is not installed, the resulting frames will end up bigger than they should
+-- be and the aliasing problem will not be fixed.
+local supersample = 4
+
+-- Set the width and height of the viewport.
+local size = {w = 640, h = 480}
+
+-- Set the number of concurrent renderings (for multi-core machines).
+local jobs = 6
+
+
+-- end of configuration
+---------------------------------------------------------------------------
+
+local fmt   = string.format
+local write = function(...) return io.write(fmt(...)) end
+local run   = function(...) return os.execute(fmt(...)) end
+
+function vec_new(x, y, z)
+    return {x = x, y = y, z = z}
+end
 
 function vec_add(a, b)
-    return {x = a.x + b.x, y = a.y + b.y, z = a.z + b.z}
+    return vec_new(a.x + b.x, a.y + b.y, a.z + b.z)
 end
 
 function vec_scale(v, s)
-    return {x = v.x * s, y = v.y * s, z = v.z * s}
+    return vec_new(v.x * s, v.y * s, v.z * s)
 end
 
-local fmt   = string.format
-local write = function(...) io.write(fmt(...)) end
-
-function render(i, v)
-    while i and v do
+function render(i)
+    while i do
+        local w, h = size.w, size.h
+        if 1 < supersample then
+            w = w * supersample
+            h = h * supersample
+        end
         local filename  = fmt("frames/anim%04d.bmp", i)
         local command   = fmt("./rasterize -o %s >/dev/null", filename)
         local out = io.popen(command, "w")
+        local e = eye(i)
+        local l = look(i)
         write("\27[80D\27[2Kframe\t %4d / %d", i + 1, frames)
         out:write(fmt([[
 U3
@@ -76,13 +110,15 @@ U3
 1.57 %f 0.1 1000
 %s
 X
-]], size.w, size.h, v.x, v.y, v.z, look.x, look.y, look.z, size.w/size.h, scene))
-        i, v = coroutine.yield()
+]], w, h, e.x, e.y, e.z, l.x, l.y, l.z, size.w/size.h, scene))
+        i = coroutine.yield()
         out:close()
+        if 1 < supersample then
+            run("convert %s -scale %dx%d %s", filename, size.w, size.h, filename)
+        end
     end
 end
 
-
 print("Animating scene...")
 
 local threads = {}
@@ -90,21 +126,14 @@ for i = 1,jobs do
     table.insert(threads, coroutine.wrap(render))
 end
 
-os.execute("rm -rf frames && mkdir frames >/dev/null 2>&1")
+run("rm -rf frames && mkdir frames >/dev/null 2>&1")
 for i = 0,(frames-1) do
-    local t = start + 2 * math.pi * i / frames
-    local v = {
-        x = math.cos(t),
-        y = 0,
-        z = math.sin(t),
-    }
-    v = vec_add(vec_scale(v, distance), center)
-    threads[1 + (i % jobs)](i, v)
+    threads[1 + (i % jobs)](i)
 end
 for _,thread in ipairs(threads) do thread(null) end
 print()
 
-if os.execute("ffmpeg -i frames/anim%04d.bmp -b 1024k -y -an scene.avi") == 0 then
+if run("ffmpeg -i frames/anim%04d.bmp -b 1024k -y -an scene.avi") == 0 then
     print("Animation written to scene.avi.")
 end