Learn/Drafting/2D Sketch Editor
Snapping
At a glance
- Endpoint — start or end of any line or arc
- Midpoint — center of any line or arc
- Centerpoint — center of any circle or arc
- Intersection — any two-geometry crossing
- Perpendicular — foot of perpendicular from cursor to a line
- Tangent — tangent point from cursor to a circle or arc
- Origin — sketch plane origin
- Visual red indicator locks cursor before you click
While any drawing tool is active, the cursor dot tracks the sketch plane in green and turns red the moment it locks onto a snap point — so you know the click will land exactly before you make it. The snap threshold is measured in screen pixels, which means zooming in naturally tightens the snap reach when you need precision and zooming out widens it when you're roughing in geometry.
Snap types
All seven snap types are individual checkboxes in the Snapping section of the docked sketch panel, and your choices persist between sessions. When several candidates fall inside the threshold, the closest one wins. Two of them depend on context: Perpendicular uses the start point of the line you're currently drawing to find the true perpendicular foot on an existing line, and Tangent finds the point where a line from your start point would kiss a circle or arc. Construction geometry snaps exactly like regular geometry, which is what makes layout lines useful.
Snaps become constraints
Snapping is treated as intent, not coincidence. When you commit an entity whose endpoint snapped onto another entity's endpoint or center, JetCad3 records an explicit coincident constraint between the two — the joint survives dragging and dimension edits instead of being re-guessed from positions later. That's the foundation the whole constraint system is built on: profiles you drew corner-to-corner stay closed.