When we work with AutoCAD, we often need to change the set of running object snaps. For a particular drawing, we might need only endpoint snap and midpoint snap. But when we work with another drawing, we might need the center, tangent and quadrant snap. Sure, we can just turn them all. But they will be more annoying than being helpful. Only activate object snaps that you use frequently.
Now if we often change the set of running object snaps, how can we do it quickly?
The OSMODE system variable
The set of object snaps is saved in the OSMODE system variable. The setting is stored as a bitcode.
Look at the table below.
If you want to turn on endpoint and midpoint snap, the value should be 1+2 = 3.
If you want to activate center, quadrant, and tangent, the value should be 4+16+256 = 276.
Does it mean you need to remember those values and good in math? Certainly not!
You can change the object snap settings to any set that you want from status bar or OSNAP dialog box.
After you get what you need, type OSMODE on the command line and press enter. Remember the value that shows there.
Now if you have 2 different sets of object snaps, it’s easy to remember. For example, I can just type OSMODE enter, type 4099 enter for my first set. Then if I need to change it to a different set, I can change it to 5137.
That is much faster than opening a dialog box, then check and uncheck several items.
Creating custom tools
If you have more than two number to remember, you may need to create custom commands. You can create a command for each value. There are many possibilities where to place the command.
You can put it on the tool palettes, on a toolbar, ribbon or even contextual menu. My favorite is to put it contextual menu. When I press SHIFT+right click, I can see my command there. With other object snap settings.
If you are interested in creating custom commands to change OSMODE, the macro is ^C^C_OSMODE;4099. You can modify the value to your preference.
Depends on where you want to place the command, below is some reference how you can create custom command:
- How to use a macro in Tool Palettes.
- Customizing AutoCAD with CUI: tutorial series.
- Create a custom command with Action Recorder.
For Action Recorder, you need to record your action, not using a macro. After you activate the Action Recorder, type OSMODE enter, the preferred value then enter again.
To Sum up
Object Snap is not the only system variable using bitcode. Bitcode system variables can be changed very quickly if you know the value. Much faster than clicking the check button on a dialog box. You only need to remember the system variable and the values. Maybe you can use a Post-it to help you remember.
And you always can create a few commands if you don’t want to remember them!