Snap to Collisions Tool Operations

As the Snap To Collisions tool has several keypresses which can add or change its functionality, we strongly suggest installing the free Astute Graphics plugin Astute Buddy, which creates a panel that dynamically updates to inform you of the various keys which can be pressed in the tool’s current context.


The Snap To Collisions tool can be used to select an art object by simply clicking on it, functioning similarly to either the native Selection or Direct Selection tool (depending on the tool preference Fully Select Groups and Compound Paths). Shift-clicking will deselect an already-selected object. Clicking on an empty area of the canvas will deselect everything.


If the Snap To Collisions tool starts a drag across the artboard from a blank spot, it simply acts as a selection tool which creates a marquee for selecting objects. The tool preference Fully Select Groups and Compound Paths controls whether it acts like the Selection tool or the Direct Selection tool, and by holding down Option/Alt while dragging, you can temporarily invert the setting on the fly. To toggle the setting and affect future marquee operations as well, press the V key.

When the drag starts over an art object, the art object (and any other selected artwork) is moved, snapping to positions where paths “collide” (first touch) other paths, either at corner points or at places where the paths share a tangency. Small magenta dots will be drawn at spots where the tool has detected points of collision. The snap tolerance is 12 pixels by default but can be changed (see Snap To Collisions: Preferences).

Snap to Collisions Tool Examples

Snap to Collisions Tool Examples

When the mouse button is released, the snapping dots will continue to be drawn for the paths over which the cursor is being hovered, providing a way to confirm whether two paths are snapped to each other without having to drag again.

If one paths snaps to another, the Snap To Collisions tool will continue to search for a second collision it can snap to while retaining the first snap, allowing you to easily place one path against two others.

Snap to Collisions Tool Example 2

Snap to Collisions Tool Example 2

Pressing one or more modifier keys while dragging artwork changes or adds tool functionality:

Shift: Constrains the motion of the dragged artwork to increments of 45° around the constrain angle.

Option/Alt: Duplicates the dragged artwork instead of moving it.

The following non-modifier keys can be pressed while dragging artwork to toggle or change various tool preferences on the fly (i.e., without having to go to the Snap To Collisions Preferences dialog):

Up/Down Arrows: When the Use Collision Spacing preference is active, increases or decreases the spacing value by the native Keyboard Increment amount (see Snap To Collisions: Preferences).

A: Toggles the Add Points to Paths at Collisions preference.

D: Toggles Snap To Dragged Path Only. By default, all paths in the selection being dragged are tested for collision against the non-dragged (stationary) paths, which allows maximum flexibility. However, if the selection being dragged is comprised of many complicated paths, this may cause lag. By enabling Snap To Dragged Path Only, Snap To Collisions will only look for collisions to the path under the cursor.

L: Toggles the Snap To Locked Paths preference.

S: Toggles the Use Collision Spacing preference.

X: Toggles the Snap To Pre-Drag Path Positions preference.