--- a/TODO	Sat Nov 24 21:55:41 2007 +0100
+++ b/TODO	Sat Nov 24 23:55:54 2007 +0100
@@ -3,10 +3,11 @@
    - optimize construction: do not use bounding boxes of shapes, instead implement box-shape intersection
  * transforms, camera
  * update Python binding, new classes
- * C++ demos
  * rename:
    - Ray.a -> Ray.o or Ray.origin
    - BBox.R -> H
+ * C++ demos
+ * more complex demos
 
 New Classes?
 ============

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/demos/buddha.py	Sat Nov 24 23:55:54 2007 +0100
@@ -0,0 +1,55 @@
+#!/usr/bin/python
+
+# this demo needs buddha model from
+# http://graphics.stanford.edu/data/3Dscanrep/
+
+import sys
+sys.path.append("..")
+
+from raytracer import Raytracer, Light, Sphere, Triangle, Material
+import Image
+
+def LoadStanfordPlyFile(rt, mat, filename, scale):
+	vertices = []
+	fp = file(filename)
+	# read header
+	tokens = (0,)
+	while (tokens[0] != "end_header"):
+		tokens = fp.readline().split()
+		if (tokens[0] == "element"):
+			if (tokens[1] == "vertex"):
+				vertex_num = int(tokens[2])
+			if (tokens[1] == "face"):
+				face_num = int(tokens[2])
+
+	# read vertices
+	while (vertex_num):
+		tokens = fp.readline().split()
+		v = [scale*float(x) for x in tokens[0:3]]
+		v[0] = -v[0]
+		v[1] = v[1]-5
+		v[2] = -v[2]
+		vertices.append(tuple(v))
+		vertex_num -= 1
+
+	# read faces
+	while (face_num):
+		tokens = fp.readline().split()
+		if (tokens[0] != "3"):
+			print "ply warning: faces of %d vertices not supported" % tokens[0]
+		f = [vertices[int(x)] for x in tokens[1:4]]
+		face = Triangle(f[0], f[1], f[2], mat)
+		rt.addshape(face)
+		face_num -= 1
+
+rt = Raytracer()
+mat = Material(colour=(0.9, 0.9, 0.9))
+LoadStanfordPlyFile(rt, mat, "happy_vrip_res2.ply", 30.0)
+
+light = Light(position=(-5.0, 2.0, -8.0), colour=(0.9, 0.3, 0.6))
+rt.addlight(light)
+
+imagesize = (800, 600)
+data = rt.render(imagesize)
+img = Image.fromstring("RGB", imagesize, data)
+img.save('buddha.png')

--- a/src/kdtree.cc	Sat Nov 24 21:55:41 2007 +0100
+++ b/src/kdtree.cc	Sat Nov 24 23:55:54 2007 +0100
@@ -89,7 +89,7 @@
 
 void KdNode::subdivide(BBox bbox, int depth)
 {
-	if (depth >= 10 || shapes.size() <= 2)
+	if (depth >= 20 || shapes.size() <= 4)
 	{
 		leaf = true;
 		return;