A model review is easier to follow when a question points to a specific location. Add a numbered note such as “Confirm whether this hole needs a thread” directly to the model, then send a viewing link with the saved notes.
Open the annotation workspace, upload a supported 3D model, and open Annotations from the toolbar if the panel is closed.
Place a review note
Choose Add annotation, click a point on the model surface, enter your comment, and choose Save annotation. Dragging still moves the view; placing a note requires a click. Notes are attached to a component's local coordinates, so their markers follow that component when the model moves or explodes.
The annotation panel lists numbered comments. Select a comment or its marker to return to the recorded viewing direction and zoom. Locating a note reveals its component and turns off section clipping so the location can be inspected. Edit or delete notes from the list.
Save before sharing
Private notes are stored in the current browser for that temporary model. Clearing browser storage removes that private copy. A new upload is a different model record, even if the filename is identical. The current limit is 50 notes per model view, with up to 1,000 characters each.
Open a single model in View mode before creating a share link. Saved notes for that model are copied into the share snapshot. Recipients can read notes and return to their viewpoints, but cannot edit the sender's snapshot. Existing links do not change when the sender edits local notes; create a new link to send a revised review.
Share access, password protection, expiry and revocation use the same controls as the model itself. Annotations are not automatically copied into the public link title or description. A public cover is an image of the chosen view: inspect it for visible annotation content before enabling a public preview. Image exports include visible annotations and measurements; leave the active annotation mode with Back before opening Share → Export current view as an image, then review the preview before sending it.
Keep a draft if saving fails
If local storage is unavailable or another tab has changed the saved record, saving stops and the current draft stays in the panel. Use Export annotations to download the notes and draft as JSON before reloading. This is a backup export; importing that JSON is not currently supported.
Turn a supplier question into a reproducible review note
For an external review, write each note so another engineer can understand the evidence without a live meeting.
A useful note has four parts:
- Location: the feature or interface being discussed.
- Observation: what the current model shows.
- Reference: the drawing, requirement or earlier revision being compared.
- Question or decision: what needs confirmation.
For example, instead of writing “wrong here,” write: “Mounting interface in Rev C model differs from the released review reference. Please confirm whether the model change is intentional before the next handoff.”
Keep computed observations separate from requests. A note can point at a region, but it does not prove a dimensional change by itself. For changed geometry, use the CAD revision comparison workflow and attach the note to the exact version pair being reviewed.
Current scope
This release supports model-anchored text, recorded viewpoints and immutable share snapshots. Persistent dimension lines, rectangles, circles, freehand redlines, replies and live collaborative editing are not included. A text note describing a dimension is not a measured dimension and does not replace a controlled engineering drawing.
Check a note after changing the view
Create one practice note on a public sample, rotate the model away and select the note from the list. Confirm that returning to its viewpoint reveals the intended component. If a section cut or hidden part made the issue difficult to see, check the restored view before assuming the marker identifies the wrong geometry.
Write the measurement method in a note when a number matters: “Overall source-axis Z extent” and “distance between selected mounting faces” describe different quantities. A note containing “20 mm” without the selected feature, unit and method cannot reproduce the check.
Before sharing an annotated review, finish editing and save the notes first. Create a new snapshot, then open it as a recipient and check that the numbered comments and viewpoints are present. Editing the local notes afterwards only changes the owner's browser record; the previous snapshot remains fixed.
Use the JSON export as a readable backup when storage is unavailable, and keep the corresponding model revision with it. Because importing that backup is unsupported, do not promise that it can automatically restore all markers into a future upload. For a changed model, recreate and verify the relevant notes rather than assuming coordinates still identify the same features.
Original article: CADProps · https://www.cadprops.com/guides/annotate-cad-model-online/