put ExportObj behind an option

include/light/light.hh

@@ -459,6 +459,7 @@ public:
     setting_bool litonly{this, "litonly", false, &output_group, "only write .lit file, don't modify BSP"};
     setting_bool nolights{this, "nolights", false, &output_group, "ignore light entities (only sunlight/minlight)"};
     setting_int32 facestyles{this, "facestyles", 4, &output_group, "max amount of styles per face; requires BSPX lump"};
+    setting_bool exportobj{this, "exportobj", false, &output_group, "export an .OBJ for inspection"};
 
     inline void CheckNoDebugModeSet()
     {

light/light.cc

@@ -1092,9 +1092,9 @@ int light_main(int argc, const char **argv)
         bsp.dlightdata.clear();
     }
 
-#if 0
-    ExportObj(source, bsp);
-#endif
+    if (options.exportobj.value()) {
+        ExportObj(fs::path{source}.replace_extension(".obj"), &bsp);
+    }
 
     WriteEntitiesToString(options, &bsp);
     /* Convert data format back if necessary */