diff -r -u panda3d-1.8.1/panda/src/pgraph/lightRampAttrib.cxx panda3d-1.8.1-patch/panda/src/pgraph/lightRampAttrib.cxx
--- panda3d-1.8.1/panda/src/pgraph/lightRampAttrib.cxx	2011-11-07 02:08:05.000000000 +0200
+++ panda3d-1.8.1-patch/panda/src/pgraph/lightRampAttrib.cxx	2013-09-01 14:33:37.385839922 +0300
@@ -96,7 +96,7 @@
 CPT(RenderAttrib) LightRampAttrib::
 make_double_threshold(PN_stdfloat thresh0, PN_stdfloat val0, PN_stdfloat thresh1, PN_stdfloat val1) {
   LightRampAttrib *attrib = new LightRampAttrib();
-  attrib->_mode = LRT_single_threshold;
+  attrib->_mode = LRT_double_threshold;
   attrib->_threshold[0] = thresh0;
   attrib->_level[0] = val0;
   attrib->_threshold[1] = thresh1;
Only in panda3d-1.8.1-patch/panda/src/pgraph: lightRampAttrib.cxx~
diff -r -u panda3d-1.8.1/panda/src/pgraphnodes/shaderGenerator.cxx panda3d-1.8.1-patch/panda/src/pgraphnodes/shaderGenerator.cxx
--- panda3d-1.8.1/panda/src/pgraphnodes/shaderGenerator.cxx	2013-02-12 17:28:17.000000000 +0200
+++ panda3d-1.8.1-patch/panda/src/pgraphnodes/shaderGenerator.cxx	2013-09-01 14:34:06.893839071 +0300
@@ -1176,12 +1176,11 @@
           PN_stdfloat t1 = light_ramp->get_threshold(1);
           PN_stdfloat l0 = light_ramp->get_level(0);
           PN_stdfloat l1 = light_ramp->get_level(1);
-          PN_stdfloat l2 = light_ramp->get_level(2);
           text << "\t // Double-threshold light ramp\n";
           text << "\t float lr_in = dot(tot_diffuse.rgb, float3(0.33,0.34,0.33));\n";
-          text << "\t float lr_out = " << l0 << "\n";
-          text << "\t if (lr_in > " << t0 << ") lr_out=" << l1 << ";\n";
-          text << "\t if (lr_in > " << t1 << ") lr_out=" << l2 << ";\n";
+          text << "\t float lr_out = 0.0;\n";
+          text << "\t if (lr_in > " << t0 << ") lr_out=" << l0 << ";\n";
+          text << "\t if (lr_in > " << t1 << ") lr_out=" << l1 << ";\n";
           text << "\t tot_diffuse = tot_diffuse * (lr_out / lr_in);\n";
           break;
         }
Only in panda3d-1.8.1-patch/panda/src/pgraphnodes: shaderGenerator.cxx~