Reading the Timeline
Every step you take is recorded as a pill on the narrow white strip down the left edge of the viewport. Reading that strip tells you how a part was built, in what order, and which step is in trouble.
One pill per step, oldest at the top
The strip is 56 px wide and runs the height of the viewport, below the logo and separated from it by a border. At the top sits a header pill: a scan-cube icon labelled Model. Click it to open the model's configuration panel. In the smart-object editor the same pill carries a sparkle icon and reads Smart object.
Below the header, one pill per step in build order, oldest first, with a small caret between each pair. Hover a pill to see the step's name. The strip is not drawn in Drawings, and it is not drawn in the code smart-object editor either, which gives that side of the screen to the code pane and its own preview slider instead.
Order is the point. Each step is applied to the result of the one above it, so the strip read top to bottom is the recipe for the part, and a step can only use what the steps above it have already made.
A smart-object placement is the one step whose pill does not show its own name: it shows the name of the object you placed.
The strip and the part point at each other
The name in the tooltip is not all a hover gives you. Rest the cursor on a pill and the part answers: the faces and edges that step produced go selection blue, everything else recedes to a translucent grey, and the step's own sketch — which you may well have hidden — is forced back on screen and drawn a second time in fat blue strokes, so it reads through the grey even when it is buried inside the solid.
That is the fastest answer there is to "which step made this bit?", and it costs nothing. The model is not rebuilt, nothing in the document is recoloured, and moving the cursor off the strip puts it all back.
The question runs the other way too. Select something in 3D and every step that made none of it fades. On a twenty-step history that turns the strip into a short list of the two or three pills worth opening. Nothing fades when nothing is selected, nothing fades when what you clicked belongs to no step at all — a principal plane, a world axis — and the step whose panel is open never fades, because a pill you are editing must not read as irrelevant to itself.
A faded pill is still a live pill: it answers a click, a right-click and a hover exactly as it did before. Fading is a reading aid and nothing else.
Colour follows what the step does
Colour is fixed per kind, so the same tool always looks the same. Sketches are green, solids that add material are violet, and cuts are red.
Colour tracks the result, not the tool. An extrude set to Subtract is coloured as a cut, not as an extrude. A red pill in the middle of a run of violet ones is material coming out.
Clicking a pill
| Gesture | What it does |
|---|---|
| Left-click | Selects the step and opens its panel |
| Shift-click | Adds the step to, or removes it from, a multi-selection |
| Right-click | Opens the context menu. On a sketch it is Hide in 3D / Show in 3D and then Delete. On every other step it is Disable / Enable and then Delete |
| Click the empty strip | Clears the selection |
A sketch cannot be disabled, and that is deliberate. Whether a sketch counts is not yours to flip: a sketch is suppressed by whatever feature consumes it, and a disabled sketch reads as a broken document rather than as a choice. So the entry is simply not on the menu, in the single-pill version or the multi-selection one. Enable is still there for a document written before that rule that already carries a disabled sketch.
Opening a panel this way also changes what the viewport shows. Editing a Part You Have Built covers that.
The playhead
A 3 px light-blue line runs down the left edge of the strip and ends in a right-triangle handle. That is the playhead, and it sits between the last step being applied and the next one.
Steps below it fade almost out of sight, but they keep their colour: a faint violet pill is still a violet pill, and that is what tells a future step apart from a disabled one, which is drained to gray. They have not been deleted: they are not part of what you are looking at.
Drag the handle to move it. The drag scrubs: it snaps to the nearest pill on every movement and travels the moment that snapped step changes, so the part reads out step by step under your hand instead of jumping once when you let go. Clicking a pill never moves it. Rolling Back Through History covers the rest.
Reading a pill's state
| Pill looks like | What it means |
|---|---|
| Full colour | Applied, part of the model you can see |
| Its own colour at half strength, inside a dashed ring | Waiting for you to point at something: the step is not finished, not broken |
| Its own colour with a small amber triangle in the corner | It built, but on a guess — check what it landed on |
| Faded, ordinary cursor, while something is selected in 3D | None of what you selected came from this step |
| Very faint, still its own colour, ordinary cursor | Below the playhead, not currently applied |
| Gray, no colour left, cursor turns to a barred circle | Disabled |
| Pastel red, pulsing | This step failed on the last rebuild |
| Gray while another pill is red | Something else failed; this step is fine |
| Spinner instead of an icon | Being recomputed right now |
Error mode is global. The moment one step fails, every pill re-tints at once: the failing ones go pastel red and pulse, and every other pill goes gray. A timeline that has turned entirely gray is not broken, it is telling you to go and find the red pill. Nothing else announces the failure.
A step that is only waiting does not do that. A revolve with no axis picked yet, a sweep with no path, a reference plane still asking which face to measure from: none of them is a failure. Nothing is even attempted, everything downstream carries on as if the step were not there, and the pill shows it by going half-strength inside a dashed ring rather than red. Nothing else in the timeline changes colour. Open the step and its panel will be asking you for the missing pick.
A warning never repaints a pill. Every pill already owns a colour that says what kind of step it is, so a step that built on a guess — a fillet whose edge was matched by measurement rather than by identity — gets a small amber triangle in its corner instead, and the message in its tooltip.
Groups
A group collapses a consecutive run of steps into one named pill. Click it to drill into a view of that group alone, with a back arrow to come out again. If any step inside failed, the group's pill carries the error tint, so drill in to find which one.
To make one: shift-click the pills you want, right-click the selection, choose Group. The new pill appears with its name already in edit mode, so type the name and press Enter. Dismiss that and the group is called Group, which tells the next reader nothing.
Group is offered only when the steps you selected are consecutive, ungrouped and at the top level. A selection with a gap in it, or one that reaches into a group that already exists, gets no Group entry and no explanation.
A group's pill carries a context menu of its own, and it is the only place two commands live:
| Gesture | What it does |
|---|---|
Right-click the group, Rename |
Puts the name back in edit mode |
Right-click the group, Ungroup |
Dissolves the group. The steps stay exactly where they are and go back to being ordinary pills |
Neither command is on a member step's menu, so drill out of the group before you go looking for them.
When it goes wrong
The whole timeline is gray. One step has failed. There is no error list and no summary, so scan for the pill that is red and pulsing and open it. When a Step Goes Red explains what you will find inside.
A pill does nothing when clicked. Two kinds of pill refuse a left-click, and the cursor tells you which one you are on. A disabled pill is inert: it is gray, the cursor over it is a barred circle, and clicking neither selects it nor opens anything. Right-click it and choose Enable. A pill below the playhead is also inert, but it keeps its colour and its cursor stays the ordinary arrow: drag the playhead down past it and it answers again.
A pill has no right-click menu. Steps below the playhead offer no context menu at all, so there is no Disable, no Delete and no Hide in 3D down there. Move the playhead back to the end first, then right-click.
Most of the strip has gone faint and you did not touch the playhead. Something is selected in 3D, and those steps made none of it. Click empty space to clear the selection and the strip comes back to full strength. Nothing has been rolled back, disabled or lost.
A sketch has no Disable in its menu. It is not missing, it is not offered: a sketch is suppressed by the feature that consumes it, never by hand. Hide it in 3D if what you want is it off the screen.
See also
- When a Step Goes Red: finding the failure the gray timeline is pointing at
- Rolling Back Through History: moving the playhead and inserting a step mid-history
- Editing a Part You Have Built: opening a step and changing it
- A Tour of the Editor: where the strip sits among the other panels