+cvar_t r_showlighting = {0, "r_showlighting", "0", "shows areas lit by lights, useful for finding out why some areas of a map render slowly (bright orange = lots of passes = slow), a value of 2 disables depth testing which can be interesting but not very useful"};
+cvar_t r_showshadowvolumes = {0, "r_showshadowvolumes", "0", "shows areas shadowed by lights, useful for finding out why some areas of a map render slowly (bright blue = lots of passes = slow), a value of 2 disables depth testing which can be interesting but not very useful"};
+cvar_t r_showcollisionbrushes = {0, "r_showcollisionbrushes", "0", "draws collision brushes in quake3 maps (mode 1), mode 2 disables rendering of world (trippy!)"};
+cvar_t r_showcollisionbrushes_polygonfactor = {0, "r_showcollisionbrushes_polygonfactor", "-1", "expands outward the brush polygons a little bit, used to make collision brushes appear infront of walls"};
+cvar_t r_showcollisionbrushes_polygonoffset = {0, "r_showcollisionbrushes_polygonoffset", "0", "nudges brush polygon depth in hardware depth units, used to make collision brushes appear infront of walls"};
+cvar_t r_showdisabledepthtest = {0, "r_showdisabledepthtest", "0", "disables depth testing on r_show* cvars, allowing you to see what hidden geometry the graphics card is processing\n"};