diff -urN rt_v5/cg.py rt_v6/cg.py
--- rt_v5/cg.py	2018-03-19 15:36:06.000000000 +0900
+++ rt_v6/cg.py	2018-03-20 15:39:53.000000000 +0900
@@ -15,24 +15,67 @@
 import wf
 import rt
 
+def if_not_set_opt(d, k, v):
+	ut.if_not_set(d, k, v)
+	ut.dic_set( d, k, lstx.opt( d.get(k) ) )
+
+def m_setup(d, m):
+	# 'fn' in d
+
+	if_not_set_opt( m, 'wh2xyz', [ ax.fn_map( m.get('fn') ) ] )
+
+	if 'xyz2t' not in m:
+		lst = []
+		if 'r' in m:
+			lst += [ cylx.new( m.get('r') ) ]
+		if 'dz' in m:
+			lst += [ fcx.new( m.get('dz') ) ]
+		if_not_set_opt( m, 'xyz2t', lst )
+
+	if_not_set_opt( m, 't2m', [] )
+	if_not_set_opt( m, 't2g', m.get('t2m') + d.get('m2g') )
+	if_not_set_opt( m, 'xyz2g', m.get('xyz2t') + m.get('t2g') )
+	if_not_set_opt( m, 'wh2g', m.get('wh2xyz') + m.get('xyz2g') )
+
+def d_setup(d):
+	# return lst [d]
+
+	if_not_set_opt( d, 'l2m', [] )
+	if_not_set_opt( d, 'm2g', [] )
+	if_not_set_opt( d, 'l2g', d.get('l2m') + d.get('m2g') )
+
+	for m in d.get( 'maps', [] ):
+		m_setup(d, m)
+
+	return [d]
+
 if __name__ == "__main__":
 
 	copen = 'copen-090419.jpg'
 	beat = 'beat.jpg'
 
-	rtd = { 'reflect': 0.3, 'reflact': 0.3, 'density': 1.1 }
+	#rtd = { 'reflect': 0.3, 'reflact': 0.3, 'density': 1.1 }
+	rtd = {}
+
+	maps = [ { 'fn': copen, 't2m': [ ax.zoom_all(2) ] } ]
 
 	data = [ {
 		'kind': 'square',
 		'rtd': rtd,
-		'l2g': [ ax.zoom_all(50) ],
+		'l2m': [],
+		'maps': maps,
+		'm2g': [ ax.zoom_all(50) ],
 	},{
 		'kind': 'ball',
 		'rtd': rtd,
 		'def_col': [128,0,0],
-		'l2g': [ ax.zoom_all(20) ],
+		'l2m': [ ax.zoom_all(20.0/50) ],
+		'maps': maps,
+		'm2g': [ ax.zoom_all(50) ],
 	} ]
 
+	data = sum( map( d_setup, data ), [] )
+
 	lights = [
 		{ 'v': [0,0,-1], 'e': 1.0 },
 	]
diff -urN rt_v5/rt.py rt_v6/rt.py
--- rt_v5/rt.py	2018-03-19 15:39:17.000000000 +0900
+++ rt_v6/rt.py	2018-03-20 15:33:43.000000000 +0900
@@ -6,10 +6,30 @@
 import line
 import lstx
 import cross
+import img
 
-def map_col(d, crs):
+def map_col(d, crs, rev):
 	def_col = d.get( 'def_col', v.all(128) )
-	return def_col
+
+	if 'maps' not in d:
+		return def_col
+
+	def f(m):
+		xyz2g = m.get('xyz2g')
+		nv_line = lstx.tr( xyz2g, 'g2l', crs.get('l') )
+		img_nv = v.z1
+		if v.dot_product( nv_line.v, img_nv ) < 0:
+			return []
+		fn = m.get( 'fn_r' if rev else 'fn', '' )
+		if not fn:
+			return []
+		(x, y, _) = lstx.tr( m.get('wh2xyz'), 'g2l', nv_line.p )
+		return img.imgs.col( fn, int(x), int(y), [] )
+
+	cols = map( f, d.get('maps') )
+	cols = filter( lambda col: col != [], cols )
+	col = v.lst_add(cols) if cols else def_col
+	return map( lambda v: min(v, 255), col )
 
 def get_col(data, lights, l_g, nest_rate=1.0, ref_len=None):
 	if nest_rate < 0.01:
@@ -27,7 +47,6 @@
 			return []
 
 	(d, crs) = min( lst, key=lambda (d, crs): crs.get('t') )
-	col = map_col(d, crs)
 
 	rtd = d.get('rtd', {})
 	base = rtd.get('base', 0.3)
@@ -39,6 +58,9 @@
 	eyev_nega = v.nega(eyev)
 	ang_nv_eyev = v.dot_product( nv, eyev )
 	ang_nv_eyev_nega = -ang_nv_eyev
+	rev = ang_nv_eyev_nega < 0
+
+	col = map_col( d, crs, rev )
 
 	def diffusivity():
 		diff = rtd.get('diff', 0.9)