From John Farrier, "Best I can tell, there is an enumeration for NEVER_CHECK_GL_ERRORS in CheckForGLErrors, defined in State. State.cpp does check to see if you want MORE error checking, but there is no way to turn OFF error checking. This change allows disabling of OpenGL error checking."

src/osg/State.cpp

@@ -80,6 +80,10 @@ State::State():
     {
         _checkGLErrors = ONCE_PER_ATTRIBUTE;
     }
+    else if(str && (strcmp(str, "OFF") == 0 || strcmp(str, "off") == 0))
+    {
+        _checkGLErrors = NEVER_CHECK_GL_ERRORS;
+    }
 
     _currentActiveTextureUnit=0;
     _currentClientActiveTextureUnit=0;