--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/demos/plyreader.py	Sat Dec 08 14:07:42 2007 +0100
@@ -0,0 +1,57 @@
+from raytracer import Triangle, NormalVertex
+
+def LoadStanfordPlyFile(rt, filename, mat, smooth, scale=(1,1,1), trans=(0,0,0)):
+	if (type(scale) == float or type(scale) == int):
+		scale = (scale,)*3
+	vertices = []
+	normals = []
+	vertex_face_num = []
+	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
+	num = vertex_num
+	while (num):
+		tokens = fp.readline().split()
+		v = [float(x) for x in tokens[0:3]]
+		v[0] = scale[0]*v[0] + trans[0]
+		v[1] = scale[1]*v[1] + trans[1]
+		v[2] = scale[2]*v[2] + trans[2]
+		vertices.append(NormalVertex(tuple(v)))
+		normals.append([0.,0.,0.])
+		vertex_face_num.append(0)
+		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]
+		v = [vertices[int(x)] for x in tokens[1:4]]
+		face = Triangle(v[0], v[2], v[1], mat)
+		n = face.getNormal()
+		for x in tokens[1:4]:
+			for i in range(3):
+				normals[int(x)][i] += n[i]
+			vertex_face_num[int(x)] += 1
+		if (smooth):
+			face.setSmooth()
+		rt.addshape(face)
+		face_num -= 1
+
+	# interpolate normals at vertices
+	num = 0
+	while (num < vertex_num):
+		if (vertex_face_num[num] > 0):
+			for i in range(3):
+				normals[num][i] /= vertex_face_num[num]
+		vertices[num].setNormal(tuple(normals[num]))
+		num += 1