Overrides are set by modifier keys to signal to the brush that it should do something different. 
◆ OVERRIDE
| Enumerator | 
|---|
| NONE  |  | 
| INVERT  | If the user holds down the Ctrl key then the brush should Invert its functionality.  
 | 
| SMOOTH  | The user is holding down the Shift key and a smooth operation should be done. 
 Brushes can choose to specify their own operation for smooth, like the Mask Tool which does a blur.  
 | 
| SMOOTHTOOL  | Internal. Used to specify that the smooth is tool specific.  
 | 
 
 
◆ MAXON_ENUM_FLAGS()