Some refinements to the POV-Ray generations.

Also add a simple program to print out gray codes of a specified width.

cube

@@ -2,18 +2,37 @@
 from scurve import hilbert
 import cubictemp
 
+"""
+    This program outputs a POV-Ray definition file. 
+
+    We render the curve into a 100x100 cube, with the mid-point of the cube at
+    the origin. You may have to fiddle with the resulting file to adjust the
+    camera location to suit the resulting image.
+
+    You can render it with a command like the following:
+        
+        povray -W500 -H500 -Q10 +A0.8 +Q11 +P ./file.pov
+"""
+
+
 pov = """
-global_settings { assumed_gamma 2.2 }
+global_settings { 
+    assumed_gamma 2.2 
+}
 
 camera {
-  location  <0, 50, 15>
-  right <1, 1, 1>
-  look_at   <0, 0, 0>
+    up 1
+    right 1
+    location  <50, 50, -200>
+    look_at   <0, 0, 0>
+    rotate z*270
 }
 
 background { color red 1 green 1 blue 1 }
 
-light_source { <50, 30, 20> color red 1 green 1 blue 1 }
+light_source { 
+    <50, 30, -200> color red 1 green 1 blue 1 
+}
 
 blob {
   threshold 0.5
@@ -21,33 +40,32 @@ blob {
     cylinder { 
         <@!i[0][0]!@, @!i[0][1]!@, @!i[0][2]!@>, 
         <@!i[1][0]!@, @!i[1][1]!@, @!i[1][2]!@>, 
-        0.1, 1 
+        4, 1
     }
     sphere { 
         <@!i[0][0]!@, @!i[0][1]!@, @!i[0][2]!@>, 
-        0.1, 1 
+        4, 1
     }
   <!--(end)-->
     sphere { 
         <@!lines[0][0][0]!@, @!lines[0][0][1]!@, @!lines[0][0][2]!@>, 
-        0.2, 1 
+        6, 1
         pigment { color red 0 green 1 blue 0 }
     }
   pigment { color red 0.5 green 0.5 blue 1 }
   finish { ambient 0.2 diffuse 0.8 phong 1 }
-  rotate 70*z
-  rotate -180*x
-  rotate -80*y
-  scale 12.5
 }
 """
 
-f = cubictemp.Template(pov)
+# Size of the PovRay cube
+SIZE = float(100)
 
-def maken(n):
+
+def maken(n, scale):
     lines = []
     current = None
-    for v in hilbert.Hilbert(3, n):
+    for v in n:
+        v = [i*scale-SIZE/2 for i in v]
         if not current:
             current = v
             continue
@@ -56,5 +74,29 @@ def maken(n):
     return lines
 
 
-print f(lines=maken(2))
+def main():
+    from optparse import OptionParser, OptionGroup
+    parser = OptionParser(
+                usage = "%prog [options] output",
+                version="%prog 0.1",
+            )
+    parser.add_option(
+        "-o", "--order", action="store",
+        type="int", dest="order", default=3
+    )
+    options, args = parser.parse_args()
+    if len(args) != 1:
+        parser.error("Please specify output file.")
 
+    c = hilbert.Hilbert(3, options.order)
+    scale = SIZE/c.dimensions()[0]
+    t = cubictemp.Template(
+            pov,
+            lines = maken(c, scale),
+            scale = scale
+        )
+    f = open(args[0], "w")
+    f.write(str(t))
+
+
+main()

gray

@@ -0,0 +1,19 @@
+#!/usr/bin/env python
+from scurve import utils
+
+def main():
+    from optparse import OptionParser, OptionGroup
+    parser = OptionParser(
+                usage = "%prog [options] output",
+                version="%prog 0.1",
+            )
+    options, args = parser.parse_args()
+    if len(args) != 1:
+        parser.error("Please specify the bit width of the desired gray code.")
+
+    width = int(args[0])
+    for i in range(2**width):
+        print str(utils.bits(utils.graycode(i), width))[1:-1]
+
+
+main()