This guide explains, step by step, how to use the AutoCAD 3DOSNAP functionality: what it does, how to enable and use it, why it may sometimes fail, useful alternatives and practical tips for working with 3D object snaps.
What is 3DOSNAP?
3DOSNAP in AutoCAD refers to the set of object snap modes that work in 3D. These snaps let you pick precise points on 3D geometry — for example endpoints, midpoints, centres, intersections, apparent intersections, nearest points, and other snap types — while you create or edit objects in three-dimensional space.
In practice you will use either the dedicated 3DOSNAP command or the regular Object Snap (OSNAP) settings and menus to enable and control which 3D snaps are active while you pick points.
When and why use 3DOSNAP?
- To ensure precision when connecting or aligning 3D corners, edges, faces and circular features.
- To pick exact points that are not coplanar (for example picking the intersection of two lines that only intersect in 3D when projected).
- To speed up modeling by letting AutoCAD automatically detect target points during commands like LINE, COPY, MOVE, EXTRUDE, etc.
How to use 3DOSNAP — Step by step
Follow these steps to enable and use 3D object snaps reliably.
Step 1 — Prepare the workspace
- Work in a 3D workspace or make sure your drawing contains 3D geometry.
- If needed, set the view so you can see the area you want to snap to (e.g., SW ISO, Top, or a custom view).
Step 2 — Enable running object snaps
- Press F3 to toggle Object Snap (OSNAP) on/off (F3 turns it on).
- Press F11 to toggle Object Snap Tracking (OTRACK) on/off (helpful for tracking from snapped points).
Step 3 — Configure which snaps are active
- Type OSNAP and press Enter to open the Drafting Settings > Object Snap dialog, then enable the snaps you want (Endpoint, Midpoint, Center, Node, Quadrant, Intersection, Apparent Intersection, Nearest, Perpendicular, Tangent, etc.). Many of these apply in 3D.
- Alternatively, right‑click the Object Snap status bar button and choose Settings.
Tip: Some deployments also support the 3DOSNAP command to toggle or present 3D-specific snap options — try typing 3DOSNAP at the command line to access those options (depending on your AutoCAD version and customization).
Step 4 — Use snaps while running a command
- Start a drawing or editing command (e.g., LINE, MOVE).
- Hover the cursor near geometry; AutoCAD will show a small marker when a snap is available.
- Click to accept the snapped point.
- To temporarily use a different snap, use a shortcut: press and hold Shift + Right‑click to open the Object Snap shortcut menu, and pick the desired snap for a one-time override.
Step 5 — Use object snap overrides (keyboard)
- When prompted for a point, you can type snap keywords such as END, MID, CEN, NEA (NEAR), INT (INTERSECTION) to force a particular snap for that point input.
Common 3DOSNAP-related problems and fixes
Below are frequent issues and simple fixes.
-
Problem: No snap markers appear / snaps not working
Fix: Press F3 to turn OSNAP on. Open OSNAP settings and make sure the desired snap modes are checked. -
Problem: I can’t snap to a point I can see (especially in 3D)
Fix: The point may be off the current plane or not detectable from the current view. Try changing view (Top, Front, Isometric) or use Apparent Intersection or 3D Intersection snap modes. Also check the UCS — set it to the correct plane or use UCS > Object. -
Problem: Apparent intersection or intersection not found
Fix: Use the Apparent Intersection snap when two objects only cross in projection. If necessary, change view direction or temporarily move geometry into a common plane. -
Problem: Temporary override doesn’t work or wrong snap used
Fix: Use Shift + Right‑click to explicitly choose the snap, or type the snap keyword at the prompt (for example type END and press Enter). -
Problem: Snaps active but the command ignores them
Fix: Some specialized commands or routines might not honor object snaps. Use object snap overrides (shortcut menu or keywords) or capture the coordinate via snapping first, then use that coordinate for the command. -
Problem: Dynamic Input or Polar tracking interferes
Fix: Toggle Dynamic Input (F12) or Polar Tracking (F10) off if they distract. They do not generally disable snaps but may mask the marker. -
Problem: UCS is rotated and snaps feel “wrong”
Fix: Reset the UCS to World or to the object plane, or use PLAN (Current UCS) to align the view, or use object-based UCS.
Alternative commands and methods
- Use OSNAP (running object snaps) and configure via the Drafting Settings dialog.
- Use Shift + Right‑click to access the Object Snap shortcut menu for quick, one-off snaps.
- Enter snap keywords at a point prompt: END, MID, CEN, NEA (NEAR), INT (Intersection), APP (Apparent Intersection), PER (Perpendicular), TAN (Tangent), etc.
- Use Object Snap Tracking (OTRACK, F11) to align points relative to snapped points without drawing construction geometry.
- Use UCS > Object to align the working plane to a face of a 3D solid, making 2D snaps accurate on that face.
- Use the OSMODE system variable (advanced): set running snap bits with an integer if scripting or automating.
Practical tips for reliable 3D snapping
- Keep OSNAP (F3) and OTRACK (F11) on for faster, more precise modeling.
- Use Apparent Intersection for picking projected intersections that do not actually share coordinates in 3D.
- Rotate your view (3D Orbit) so the desired snapping point is visible and not obscured by overlapping geometry.
- Use object‑based UCS when working on a face — press UCS > Object and click the face to temporarily make snapping on that face behave like 2D.
- If you frequently use a specific set of snaps, save them as your default in the OSNAP dialog so they’re always active.
- Use Shift + Right‑click for quick single-use snaps rather than changing global settings.
- For scripts and LISP routines, consider using OSMODE to set required snaps programmatically before running operations.
FAQ
What is the difference between 3DOSNAP and OSNAP?
3DOSNAP refers specifically to snapping modes and behavior that are intended for three-dimensional objects. OSNAP (Object Snap) is the general running object-snap system in AutoCAD. In practice you enable and configure 3D snaps through the OSNAP dialog or the 3DOSNAP command if your AutoCAD version exposes it.
How do I temporarily use a different snap while drawing?
Hold Shift + Right‑click to open the Object Snap shortcut menu and pick the snap you want for that single point. Alternatively type the snap keyword (e.g., END, MID) at the command prompt.
Why can’t I snap to the center of a 3D circle or arc?
The visible center may not lie on the current UCS plane or view projection. Try changing view, enable Center snap in OSNAP, or set the UCS to the plane of the circle (UCS > Object) so the center is correctly detected.
Does the visual style (Wireframe, Realistic) affect 3DOSNAP?
Visual style does not directly change snapping logic, but some visual styles can make geometry harder to see. If snapping seems incorrect, switch to a clearer visual style (e.g., 2D Wireframe or Shaded with edges) or rotate the view for a better angle.
How can I snap to an intersection that only appears when projected?
Use Apparent Intersection (an OSNAP mode) to pick where two objects appear to intersect in the current view but do not actually share coordinates in 3D.
Are there keyboard shortcuts to toggle snaps and tracking?
Yes — F3 toggles Object Snap (OSNAP); F11 toggles Object Snap Tracking (OTRACK); F12 toggles Dynamic Input. Use these to quickly change behavior while modeling.
My snaps are enabled but AutoCAD still won’t pick the point — any checks I should do?
Check that the desired snap type is enabled in OSNAP settings, ensure nothing is filtered out by selection filters or command-specific limitations, verify the UCS and view orientation, and try a snap override (Shift + Right‑click or keyword) to force selection.