Valve GoldSrc/Source engine skybox to Cubemap composer

valve2cube.py

from PIL import Image
import sys, os, re
from os import path

transforms = (
	('FT', 90), ('BK', 270), ('LF', 180), ('RT', 0), ('UP', 0), ('DN', 180)
)


def usage():
	print "%s <skyname> (without direction suffix UP|DN|FT|BK|LF|RT)" % (sys.argv[0],)
	sys.exit(1)

if __name__ == "__main__":	
	if len(sys.argv) <= 1:
		usage()
	
	arg = sys.argv[1]
	
	dir = path.dirname(arg)
	prefix = path.basename(arg)
	cubefilepat = re.compile(prefix + r'(UP|DN|LF|RT|FT|BK)\..*', re.IGNORECASE)
	print "Scanning:", dir
	
	files = {}
	
	for f in os.listdir(dir):
		r = cubefilepat.match(f)
		if r is not None:
			files[r.group(1).upper()] = r.group(0)

	if len(files) != 6:
		print "Too few or too many files:"
		print files
		sys.exit(1)
	
	ft = Image.open(path.join(dir, files['FT']))
	w, h = ft.size
	ft.close()
	print "Skybox size is: %dx%d" % (w,h)
	
	print "Compositing cubemap ..."
	cm = Image.new('RGBA', (w*6, h))
	
	for direction, rot in transforms:
		fn = path.join(dir, files[direction])
		side = Image.open(fn)
		siderot = side.rotate(rot)
		side.close()
		box = (w * transforms.index((direction, rot)), 0)
		tox, toy = box
		print "%s to X:%d, Y:%d, r:%d" % (files[direction], tox, toy, rot)
		cm.paste(siderot, box)
		siderot.close()
	
	cm.save('cubemap.png')