Rollback and Editing Features#

Overview#

Rolling back means moving the Timeline Marker (the marker at the right end of the timeline) to an earlier point. Everything to the right of the marker becomes inactive: it is not computed and does not appear in the model. Everything to the left is live. With the marker at an earlier position you can:

• See what the model looked like at that stage.
• Edit a feature in its original context.
• Insert new features that will be placed at the marker, between existing ones.
• Diagnose errors by finding the first step where things go wrong.

Editing an old feature is the core move of parametric work. You rarely need to roll back to do it, because double-clicking a feature edits it and Fusion recomputes the rest. But rolling back is the right tool when you want to add something "before" a later feature.

Where to find it#

• Drag the marker along the timeline to view the design at that point.
• Playback buttons to the left of the timeline: Move to Beginning, Previous Step (one feature back), Play (steps through each feature), Next Step (one feature forward) and Move to End.
• Edit Feature: double-click a feature, or right-click it and choose Edit Feature. Sketches are edited with Edit Sketch.
• Change Parameters: Modify > Change Parameters edits feature parameters without opening each dialog.
• Capture Position: on the toolbar, Position > Capture Position (appears after you move or rotate components; details below).

Step by step#

Edit a past feature without rolling back#

1. Double-click the Extrude icon in the timeline (or right-click > Edit Feature).
2. The dialog opens with the original values. Change Distance from 20 mm to 30 mm.
3. Click OK. Later features recompute. If any fail, see Timeline errors.

Roll back and insert a feature#

1. Drag the marker to just after Fillet1 (or use Previous Step). The model appears as it was just after the fillet.
2. Create a new feature, for example a Hole on the top face.
3. The new feature is added to the timeline immediately after the marker, and the later entries stay on the right.
4. Drag the marker to the right end (or click Move to End) to restore the full model. Fusion recomputes everything after the inserted feature.

If the later features referenced geometry that the inserted feature now changes, some references may shift. Check the result.

Edit a sketch in context#

1. Roll back to just after the sketch (or right-click the sketch > Edit Sketch).
2. Change dimensions, or add and remove constraints.
3. Finish Sketch.
4. Roll forward. Features that consumed the sketch update. If you removed a profile that was extruded, the extrude may break.

Change the order by rolling and creating#

1. If a feature should have come earlier, roll to the earlier spot and recreate it.
2. Delete the original later. Drag-reordering is quicker when permitted (see The timeline).

Capture Position#

Capture Position is an assembly command (Autodesk's "Capture or revert position of components"). It captures the positions of components you recently moved or rotated, so the current positions are kept as you continue editing.

1. In the canvas, move or rotate one or more components. A Position panel appears in the toolbar.
2. Choose Position > Capture Position to capture proactively, or choose Position > Revert to return the components to their most recently captured position.
3. If you start a command that depends on component positions (for example Joint Origin), Fusion prompts you with Capture Position or Continue (which reverts to the last captured position).

Positions are captured silently as you move them until you activate such a command. Capture Position is separate from joints: joints define relationships between components.

Options reference#

Tips and pitfalls#

Tip: Rolling back to diagnose is the fastest debugging method. Binary search: drag the marker to the middle; if the model is fine there, the problem is to the right.

Tip: To "see what the part was like before the fillets" without editing anything, roll back. No undo stack involved.

Warning: Do not leave the marker rolled back when you save or hand off a file. Some teammates, drawings and exports will see the partial model. Always return the marker to the end.

Warning: Inserting a feature earlier can change topology (face and edge identities). Later features that referenced edges by identity can break or attach to the wrong edge. Check the whole model after inserting.

Warning: When you roll back, new sketches and features cannot reference geometry that exists only to the right of the marker.

Edit-in-context habits:

• Edit the sketch, not the feature, when you want to change a dimension. Features hold distances; sketches hold shapes.
• Prefer editing parameters (Change Parameters) over reopening dialogs when the number matters to more than one feature.
• If an edit results in many red icons, undo and understand why before you fix individually.

Insert versus append#

If you are at the end, new features append. If the marker is rolled back, new features insert. Many "I can't find my new feature" moments are just this: the feature is in the middle of the timeline, not at the end.

Rollback and components#

Because the timeline is one global sequence, rolling the marker back affects all components. A component created after the marker disappears from the canvas. This is normal; it returns when you roll forward.

What actually happens when you edit#

Autodesk's help says that when you change a parameter the timeline recomputes and features that reference it update. In a long timeline, editing an early sketch can therefore pause for a while after you click Finish Sketch, because downstream features are recomputed (the rollback-while-editing detail is general knowledge, not stated in the mirror). Edit an early feature while Automatic Compute is on and each change triggers a rebuild; for heavy models, edit parameters with Automatic Compute off and Apply once.

Edit versus roll back versus insert#

Worked example with numbers#

A bracket timeline: Sketch1 (60 x 40) > Extrude1 (10 mm) > Hole1 (6 mm, 8 mm from each edge) > Fillet1 (3 mm on the top edges) > Pattern1 (hole pattern).

1. You realize the part should have a 1 mm chamfer on the bottom edges before the holes are added so the hole edges stay sharp. Drag the marker to just after Extrude1.
2. Create Chamfer 1 mm on the bottom edges. It appears right after Extrude1, and the other entries stay to the right.
3. Drag the marker to the end. Fusion recomputes Hole1, Fillet1 and Pattern1 with the chamfer present.
4. Check each feature: Hole1 was placed on the top face, which the chamfer did not touch, so it survives. Fillet1 referenced the top edges, unaffected. The bottom edges you chamfered were not referenced by later features. Result: no errors.
5. Now repeat with a chamfer on the top edges (the edges Fillet1 used). The Fillet's edge references are now gone or replaced and Fillet1 will show an error; you have just found a fragile dependency without breaking anything permanent.

Capture Position example#

You drag a lid component up to inspect a part below it. Before starting a command that depends on component positions, choose Position > Capture Position to keep the lid where it is, or Position > Revert to put it back at its last captured position. Decide on the pose first, because whatever you capture is what the next command sees.

Edit-in-context tips#

• To change a dimension that several features share, edit the parameter, not each feature.
• When you edit a sketch and the profile you edit is used by two features, both update. If you only want one to change, make a copy of the sketch before editing.
• If a rolled-back state is part of a design review, say so in the version note; a colleague opening the file sees the model at the marker, not the end.
• While rolled back you cannot reference geometry that exists only to the right of the marker, including bodies and sketches created later. If you need a reference, create a construction plane earlier instead.

Failure modes and fixes#

Practice exercise#

Practise mid-history edits and learn what each one breaks.

1. Build the bracket: Sketch1 (60 x 40), Extrude1 (10 mm), Hole1 (6 mm, 8 mm from each edge), Fillet1 (3 mm on the top edges) and Pattern1. Rename every item. Save a version.
2. Drag the marker to just after Extrude1. Add a 1 mm chamfer on the bottom edges. Roll forward and confirm there are no errors.
3. Roll back to Extrude1 again and add the chamfer to the top edges; roll forward and note which feature fails and why. Undo.
4. Edit Sketch1 to change the width from 40 to 60 mm and confirm the chamfer and holes follow.
5. Move a lid component up 25 mm, then use Position > Capture Position and add a feature that cuts through both parts. Try Position > Revert on a second move to see the difference.
6. Intentionally break something: roll back before the extrude, delete the profile in the sketch, roll forward and read the errors. Undo.
7. Time how long step 4 takes with Automatic Compute on, then with it off plus Apply (Change Parameters). Note the difference.
8. Save while rolled back, close the file, reopen it, and observe the state; then fix it.

Expected result: you can add features mid-history, predict which later features will break, and know the habits that avoid unplanned rollback states.

Related#

• The timeline
• Timeline errors
• Design-for-change patterns