The Snaps and Constraints allow you to control how you draw and move objects. Using the different settings will allow you to draw straight lines and rotate objects evenly.
Add a green checkmark to activate each of the controls.
No Snaps: This will allow you to turn all Snaps and Constraints off. Remove the checkmark to restore the last used settings. (Hotkey: I)
Point: This will allow you to snap to all of the points on any shape in your project.
Line: This will allow you to snap to any edge of any shape in your project.
Grid: As you draw a shape, your lines and arcs will snap to the grid. This also affects the movement of shapes or objects as well.
Center Point: This will snap to the center point of any arc in your scene, where each radius line starts.
Perpendicular: Using this option, you can move an individual line or arc perpendicular to itself.
Midpoint: This will snap to the midpoint of any line or arc as you draw.
Auto Adjust Arcs: This option will change the results you see while using the move or scale tools to adjust an existing arc. While on, the move and scale tools will attempt to maintain a proper freeform shape. When off, moving arcs will draw a line.
You can customize the strength of your snaps and constraints in the Configuration Menu on the 2D Interaction Tab.
These sliders allow you to adjust the strength of your snaps. The higher the pixel number, the stronger the snap will be.
The pixel number represents the number of pixels away your cursor needs to be in order for the snap to take effect.
You may choose an Angle Snap setting by clicking on the radio button.
None: This option will turn off angle snapping, which affects drawing shapes or rotating objects and shapes in your project. (Hotkey: K)
Relative Angle: With this option, as you draw a shape, lines and arcs will snap 45 degrees relative to the previous line or arc drawn. (Hotkey: L)
World Angle: With this option, as you draw a shape or rotate an object, it will snap to every 45 degrees globally. (Hotkey: G)
Auto-complete setting gives you the power to draw shapes and then simply double click on the last point to complete the shape automatically. (Hotkey: O)
It works just like an automatic Outline tool: as you draw along an existing shape (like a step along a pool beam), a blue line will now appear. If you want to trace a portion of the autocomplete line, simply press and hold CTRL.