The window

Everything you see in the 3DCraft window, and how to look around, play the history and point at things.

The window (craft3d) is where you watch the agent work, look at a design and show the agent what you mean. 3DCraft has no toolbar of modelling buttons: every change to a design comes in as a command. An agent sends it (Install › Connect an AI agent), a Jig's form sends it (Using a Jig), or a program does (Programs on 3DCraft).

What the window does by itself is open, save, import and export files, and let you look, play, click and select.

The status bar

At the bottom is the status bar. It shows the document's units, its file, when it was autosaved, the last command and its answer, and which renderer drew the picture.

When 3DCraft works for more than a moment, a small spinner on the right says what it is doing: Opening gridfinity-bin… 41/57 while a file's features are built, then Checking 27 assertions… 5/27 while its checks are measured. The model is already there to look at. Quick work never shows the spinner, and once shown it stays a little while, so it does not blink.

Until a newly opened file has something to show, the middle of the view says Opening …. While a motion plays, the status bar says Playing and the moment's t. An error shows at once and stays.

At the right end of the status bar is the agent pill. Its colour says how agents stand:

• outlined grey, Agents off;
• outlined indigo, Waiting for an agent;
• indigo, Claude Code connected; with a turning mark, what the agent does at this moment (Claude Code · feature.fillet);
• amber, when an agent asks you something (Claude Code asks for a folder).

Click it for the agent panel (Install › Connect an AI agent). The browser has no pill: agents drive the desktop app only.

The start screen

Without a document, the window shows the start screen (its picture is in Your first five minutes):

1. At the top, the name and version, with Check for updates beside the version, and the line Parametric CAD built with and for AI. Start a document, open one, or let an agent model while you watch. Check for updates opens a page of the website in your browser that says whether there is a newer version (Install › Installing a newer version). The web version has no such link: it is always the latest.
2. New part, New assembly and Open….
3. Examples, with three tabs at its right: Parts, Jigs and Assemblies. Only the chosen tab's cards show. The tab you chose stays chosen while 3DCraft runs.
4. A line that says what the tab holds, with More examples at its right. More examples opens the gallery of every example, Jig and assembly, 3dcraft.dev/examples, in your browser, at the part for the tab you are on.
5. The cards. A click on a card opens it in a new tab, named after the example. Nothing is asked when you close it again, unless you changed something: then 3DCraft asks whether to save your version. One that takes a while to open says so on its picture, such as about 3 s.
   • Parts: ten finished parts, with their whole history to play back. The first two, the steel bookend and the T-slot aluminium profile, are marked Start here: they are the simplest. A part with sizes you may change opens on its Parameters tab.
   • Jigs: the laser-cut box, the Gridfinity bin, the dovetail drawer, the sheet-metal enclosure, the planetary gearbox and the sundial. Each opens on its Parameters tab (Using a Jig).
   • Assemblies: the toggle clamp, the Jansen walker, the scissor jack and the radial engine. Each opens on its Assembly tab with its player on Motion: press play and it moves (Assemblies). Its sizes, where it has any, are on the Parameters tab beside it.
6. Recent at the left: the files you opened or saved last, each with the icon of its kind and how long ago it changed. Connect an AI agent at the right: the same panel as the agent pill's, with the Allow AI agents switch, the work folder, and the buttons that copy the configuration for your AI tool. In the browser, it says instead: In the browser an agent cannot drive 3DCraft yet. Use the desktop app to connect one.

The start screen comes back when you close the last tab.

Menus and tabs

Tabs run along the top, one per open document, each with a small icon of its kind (a part, an assembly, a Jig). A Jig opened to be used also says Jig. An amber dot at a tab's right marks unsaved changes; the close × takes its place under the pointer.

Ctrl+Tab goes to the next tab and Ctrl+Shift+Tab to the previous one. Ctrl+W closes one, and asks first when it has unsaved changes (Save, Don't Save, Cancel). On a Mac, ⌘W closes a tab; Ctrl+Tab stays Ctrl+Tab.

The File menu:

Under them are the open documents: click one to switch to it. A recent file that is not there any more is greyed out. The list is kept in 3dcraft/recent-files.json in your state folder, next to the autosaves, and two windows open at once each keep what the other added. The browser keeps no recent files.

The Edit menu:

Every change counts, whoever made it: you, or an agent over MCP. An item is greyed out when there is nothing to undo or redo, and while a parameter is being dragged or set. While you type into a field, Ctrl+Z undoes your typing instead. In a Jig in use the only changes are those of its parameters, so Undo takes back the last parameter you set.

The View menu:

The appearance changes the panels, the start screen and the dialogs. The menu bar, the tabs, the status bar, the menus and the popovers stay dark, and the model's view stays as it is, so pictures look the same whichever you choose.

The Help menu:

• User guide opens this guide in your browser, for the version of 3DCraft you have.
• Keyboard shortcuts (also F1) lists every key and mouse action (Reference › Keys and mouse).
• Open data folder shows 3DCraft's folder: the autosaves, what can be recovered after a crash, and the recent files (not in the browser).
• Connect an AI agent… opens the agent panel over the pill (not in the browser).
• Check for updates… opens a page of the website in your browser, with your version in its address. The page says whether there is a newer version and offers it (Install › Installing a newer version). 3DCraft itself does not connect. Not in the browser, which always runs the latest version.
• About 3DCraft gives the version and the commit it was built from, the platform, the licence (MIT), links to the guide, the source and the update page (not in the browser), and the renderer in use. Copy system info copies those lines for a bug report.

The side panel

The left panel has tabs, chosen by the kind of document:

• a part has Features, Variables and Bodies, and Agent (below);
• an assembly has Assembly (its instances, mates and checks), Variables and Agent;
• a document with public parameters, such as a Jig, has Parameters first.

When the tabs do not fit, the rest are behind ⋯. Drag the panel's right edge to make it wider or narrower; it keeps that width whatever it shows.

Features

One row per step of the history: an icon for its kind (sketches in indigo, datums in petrol, as in the view), its name, and its key value at the right, such as Extrude 8 mm, R18 × 60 mm (a cylinder), 3 × 22 mm (a pattern) or − Bore (a subtraction and its tool).

• A sketch sits under the feature made from it, folded: click › to open it. Datums that follow one another fold into one Datums row in their place. The order shown is always the history's.
• The filter at the top keeps the rows whose name, kind or value holds what you type.
• The line under the filter says how it went: 23 rebuilt · 7 checks pass, 1 failed · 3 not rebuilt, 89 rebuilt · 16 pass · 1 not proven, or Rolled back to Bored · 10 of 25. A dot that says done or failed carries a tick or a cross, so it does not rest on colour alone; the others are small and plain: grey for what is not rebuilt, not proven or still being measured, indigo when rolled back.
• Hold the pointer on a row: what it uses (↑) and what uses it (↓) get an indigo tint, and a strip at the foot of the list names them and counts the later features that depend on it. The row's grip (⠿) and eye show too.
• Click a row to select the feature. Click the value of the selected row to edit it in place: Enter sets it, as one step to undo; Escape leaves it.
• Double-click a row, or click the ⌖ on the row under the pointer, to fly to what it made.
• The eye hides that feature's body, sketch or datum in the view. It stays on a hidden row, struck through. The model itself does not change.
• A feature that fails is a red row with its reason and two buttons: Show where flies to what it is made from, Edit opens its value. The features made from it are dimmed: they are not rebuilt. The ones that do not depend on it are built as usual (Troubleshooting › A feature fails).
• Drag a row by its grip to move it in the history (feature.move). A place before what it is made from, or after what is made from it, is refused before you drop it: the indigo line does not show there.
• Right-click a row for its menu: Edit…, Rename, Show dependencies (the hover's marks stay until Escape), Roll back to here (Roll forward to end on the last row), Suppress, Hide, Copy id (for a message to an agent) and Delete. Each is a command, so an agent can do the same, and every one can be undone.

Checks sit under the list: Checks 7 · all pass, then each check measured against its limit, such as 7 mm ≥ 5 mm. A failing check is red, with its reason under it, and the line at the top says 1 of 7 checks fails. A check that is not proven, neither passed nor failed, has a grey dot, with what it must be and why under it (Measuring and assertions › Assertions); the Moka pot in the studio picture below has one. Click a check to fly to what it measures. The checks fold to their heading while something is selected, or when the panel is short, to make room.

What is selected shows at the foot of the panel:

• a face: its surface (plane, cylinder R …, cone, sphere, torus, spline), its area, and its normal or axis;
• an edge: its curve, its length, the two faces it lies between and the angle there;
• a body: its volume, mass, area and box.

Made by links to the feature that made it, and Name is its persistent name, the name an agent uses. Measure measures a face's wall thickness, or the distance between the first two things selected; Copy name copies the name.

Variables

The document's variables as a table: name, value or formula, result. Variables are grouped by the group a public parameter was given, or by a prefix two of them share (base_t, base_r under Base). A formula is written in indigo on a line of its own, its result at the right.

Click a value or a formula to edit it: Enter sets it, as one step to undo; one that does not work out says why under it. Add variable opens a new one to fill in; Enter makes it. The document's units and tolerance fold away at the foot.

Bodies

One row per body the design ends with: its colour, its name, its mass (or its volume without a material) and its eye. Click a body for its card: Material (choose a preset: it sets the density and the look), density, colour, volume, mass, area, box, faces and edges, and whether it is a valid closed solid.

When the body's faces carry colours of their own, the card has Clear face colour (or Clear 3 face colours, with their number), and a Shared row when some of those colours are shared with another body (Modelling features › Colours and materials). The totals are at the foot. The bodies that booleans used up are folded under Tool bodies: open it to see them and where they went.

Parameters

A Jig opens on Parameters, its form (Using a Jig). Its other tabs are there to look at.

Agent

While agents are allowed, or once an agent has worked on the document, the side panel has an Agent tab. It shows who is connected, then what agents did to this document, newest first: when and which agent, the command in words, the features it made, why a command failed, and in italics what the agent said it meant to do.

A feature an agent made, or last changed, carries a small indigo ✦ after its name in the Features tab. The desktop app only: in the browser, agents cannot connect.

The history player

At the foot of the side panel is the timeline: drag it to see the design as it was after any step of its history. Features after that step are greyed, and the step is named at the top of the view, such as Step 2/6 · Extruded profile · extrude (its place, the number of steps, its name and its kind). Looking back never changes the document.

Under the timeline is the player, one row like a video player's. The round amber button plays and pauses, and where you are is beside it (3 / 6).

The keys work while the pointer is over the view or the feature list and you are not typing in a field. In a narrow feature panel Orbit is left out.

Each step is shown once its model is built, and for at least 0.8 s at 1×, so a heavy model never skips a step. Playing stops at the end, when the document changes or when you switch tabs. While you play, the row of the step shown is outlined with a dashed line in the feature list, which scrolls to keep it in view.

Every step is shown as finely meshed as the whole design, so a part that does not change between steps keeps its look, and stepping through a history you have seen before is immediate.

The roll-back bar

The amber roll-back bar in the feature list sits after the last step built. Drag it up to a step, or choose Roll back to here on a row's menu, and the design is built only up to that step. New features then go in right after it: a way to insert something early in the history.

Drag it back to the end, or choose Roll forward to end (on the last row's menu, or a right click on the bar), to build the whole history again. Unlike the timeline, the bar changes what is built. While you look back with the timeline, clicks in the view do not select; press End first.

Playing a motion

A design can also move: a crank that turns, a lid that opens. Its motion is driven by a timeline variable t, a plain number from 0 to 1, and formulas of t, such as a crank angle 360 deg * t (Engineering checks › Over a motion). A t with a unit (a thickness called t) is not a timeline: rename it first.

With a timeline, History and Motion appear above the player. In Motion:

• the slider runs over t, and the player plays it from 0 to 1 in 4 s at 1×;
• the step buttons move t by 0.05, and Loop starts again at 0;
• Back and forth, under the row, turns round at the end;
• Collisions draws the parts that overlap in red, and says under the player how many pairs overlap at that moment, such as 2 colliding.

The moment shows beside the play button (t 0.500). While it plays, the status bar says Playing; after an agent shows a moment (view.motion, as in the picture below), the status bar names it too (t = 0.500). Nothing is written over the view while the player is in sight. When it is not (the side panel on its Parameters or Agent tab, or put away), the view names the moment itself, such as t = 0.500 · collision: Wall and Crank.

As with the history, nothing in the document changes. Only the features that use t are rebuilt for each moment, so a heavy model plays slower rather than skipping. An assembly has no history of its own, so it shows only Motion: its parts are moved, not rebuilt (Assemblies).

In this picture Collisions finds two pairs in the toggle clamp, drawn in red: the spindle's rod and each of the two nuts on it. That is the tool doing its job. The nuts are drawn with a 5 mm hole, the size drilled for an M6 thread, on a 6 mm rod, so they overlap where their threads grip. Rod and nuts move together, so the pairs are the same at every moment of the motion. The collisions to look at are the ones that come and go as it moves. The handle's grip is red by its own colour.

While a motion plays, the view draws lighter so it keeps up. In the studio look it leaves out the frames a still picture averages, the depth of field, the ambient occlusion and the reflections; the shadows stay. As soon as you pause or stop, the full look comes back and settles. Screenshots and recordings are always at full quality.

When the moments of a motion are slow to make (an assembly whose parts are rebuilt as it moves, a heavy part), the player asks This motion is heavy — bake first? under the slider. Bake makes the moments of a play ahead (motion.bake) while it goes on playing, with a bar that shows how far it is; afterwards it plays smoothly. Not now hides the question for that document until you close 3DCraft. A motion that is quick to show, but whose parts are rebuilt as it moves, is baked by itself the first time it plays.

An agent drives the motion with commands of its own (Reference › The window, for agents and programs).

Looking around

The display bar at the bottom of the view:

• Sketches and Datums show or hide sketches and construction planes, axes and points. In an assembly the first button is Mates instead: it shows or hides the markers of its mates. In your window Sketches starts on and Datums starts off, so switch Datums on to see the datum planes, axes and points; flying to a datum from its row switches it on too. Most pictures in this guide were taken with both switched off.
• Edges shows or hides the dark lines along the bodies' edges. An edge you point at or select is still drawn.
• See-through makes the bodies transparent (drag its slider), to look at pockets and cavities.
• Section cuts the view open with a plane across X, Y or Z, through the middle of the model at first. Offset moves it and Flip side keeps the other half.

The pictures in this guide show a window 1400 points wide (the start screen's 960 high). In a smaller one, such as the 1280 × 800 that 3DCraft first opens with, Sketches, Datums and Edges show their icons without words, and the start screen scrolls to show its last panels. Narrower still, Fit, Iso, Studio, Analysis and Section show their icons only too, and the See-through and Offset sliders lose their labels. Hover for the names.

A new document keeps everything that is shown in view as it is built, sketches included. A document you open is framed on its bodies (on its sketches when it has no body), and the view keeps them framed as the model changes. Fit, and F with nothing selected, frame everything that is shown, sketches included, and the view keeps that framed from then on; so do Iso and the view cube. Once you pan or zoom, the view stays where you put it.

None of this changes the document. Each tab remembers its own camera, section and see-through. A heavy model first shows a quick picture, then the sharp one (the status bar says refining).

On a phone or a tablet

The browser on a phone or a tablet, and any window narrower than about 800 points, gets a narrow layout:

• The buttons get finger-sized as soon as you touch the screen, at any width. The drawer is for narrow windows only, so a tablet held upright at 820 points keeps the feature list beside the view.
• Where the display bar has no room for the section's options, they get a row of their own just above it.
• A model with a history or a motion gets a small player above the bar (play or pause, the steps or the slider, and where it is) while the drawer is shut; the drawer holds the whole player. On a phone or a tablet only the three buttons and where you are stay; the timeline's ends take you to the first step and the last.
• A Jig in use shows its parameters as a sheet under the model on a phone, so every change shows at once above it; on a tablet the side panel stays docked beside the model.
• The Studio and Analysis options open as a sheet from the bottom of the view, with Light, Scene and Lens as tabs for the studio look; × or the chip closes it.
• When the tabs do not fit, All at the end of their row lists every open document, and the status bar keeps to what you act on. A question about an agent's access comes as a sheet with the answers one under the other.

The studio look

Studio, beside Persp and Ortho at the top right, switches between two looks:

• the plain look, flat and clear, which is best for modelling;
• the studio look, which shows what a part will look like: its colours, how metal and how rough its faces are, lit by a photographed environment.

Three environments come with 3DCraft: studio (soft boxes, the default), outdoor (sky and sun) and workshop. The light falls from the environment's brightest direction and casts soft shadows on the model and on a ground under it; corners and grooves darken where little light reaches. A see-through or cut-open view is lit the same way.

Studio is a split button. The chip switches the look on and off; the small ▾ caret on its right opens and closes the look's options. Switching the look on opens them in a popover under the button row:

• the environment and how far it is turned;
• the exposure, the background, the ground and how much it reflects;
• the tone curve (AgX, ACES or Linear), shadows, ambient occlusion, reflections and bloom;
• a Lens that blurs what is out of focus.

A change shows at once. Click the caret again, or press Escape, to close the options: the look stays on. In a short window the options scroll inside the popover.

The lens. Lens switches depth of field on. Aperture is a slider of the usual f-stops, f/1.4 (most blur) to f/22 (nearly all sharp). Focus says where it focuses:

• Selection (the default when you switch it on): on what is selected, in the view or in the feature list; it follows as you select something else;
• Click: on the point you clicked last;
• Centre: on the model's centre;
• Distance: at a distance along the view, with a slider of its own.

With nothing selected, a selection that is hidden, or no click yet, the lens focuses on the centre, and the popover says so. In an orthographic view there is no lens, and nothing is blurred. While the lens is on, what is selected keeps its own colour and is marked by its outline. The blur follows the document's length unit, as a real camera would: a small part seen close up has a shallow depth of field.

While the camera stands still, the window keeps refining the picture, so edges smooth out and the blur fills in. Moving the camera starts again from a sharp first frame.

In the browser the studio look is drawn simpler while you turn, pan or zoom the view, and in full again a moment after you let go. On older graphics (WebGL2) it has no shadows, no darkening in corners, no reflections and no depth of field.

The look is a view: the document does not change. Colours, metals and materials are given to the bodies themselves (Modelling features › Colours and materials). An agent sets the same look with ui.set, and craft3d-cli render takes it too (Reference › The window, for agents and programs).

Surface analysis

Analysis, beside Studio, shows the quality of the surfaces instead of their shading. It is a split button as Studio is: its popover chooses what to show, with its options as sliders and a legend that says what the colours mean. Its ▾ caret (or Escape) closes the popover and keeps the analysis on. While an analysis is on, the view is drawn plainly, so the studio look's caret is greyed out until the analysis is off.

• Zebra: black and white stripes reflected in the surfaces, as a car body reflects the lights of a tunnel. Where two faces meet with the same tangent plane (G1) but a jump in curvature, the stripes kink. Where the curvature carries on too (G2), they run on smoothly. The stripes follow the view, as reflections do: turn the model to see a seam from several sides.
• Highlight: highlight lines, the lines of a light panel above the model, drawn where the surface's normal points at them. They stay put when you turn the view, so they show a surface's flow on the part itself.
• Curvature: a colour map of the curvature, from blue (most negative) through pale to red (most positive). Gaussian is negative on saddles, positive on domes, and zero on flat and cylindrical faces; mean is positive where the part bulges out; max is the larger of the two principal curvatures. The numbers come from the exact surfaces, not from the triangles on screen.
• Draft: for moulded parts. Faces that leave the mould along the pull direction with at least the least draft are green, faces that leave it the other way blue, and faces too steep to leave either way red.

Combs draw the curvature of edges as spikes standing off the curve, as long as the curvature: where the comb's outline jumps, the curvature does.

The analysis is a view, like the look: the document does not change. The numbers behind the colours are measures too (Measuring and assertions › Surface quality).

Pointing at things

A click selects what is under the pointer: a corner (vertex) when one is within a few points, else an edge, else the face.

The agent sees your selection. The selection belongs to the document, not to the window, so the agent reads it: each item with its name, the body, the feature that made it, its shape (a hole's radius and axis, a face's direction) and the size that drives it. So you can say:

Make the hole I selected 6.5 mm.

and the agent finds the size behind that hole and changes it.

The other way round, the agent can show you what it means. It can light up a face, an edge or a corner in your view, set the selection you see, fly the camera to a feature, play the history, and take a picture of the window to look at itself (Programs on 3DCraft › The window's control channel).

When something goes wrong

When a command fails, the status bar shows it in red with its message, and a Copy details button that copies a short report for a bug report. When a file action you started yourself fails (Open, Save, Import, Export), a dialog says what went wrong (Troubleshooting › Reporting a problem).

When 3DCraft was not closed properly (a crash, a power cut), the next start shows a bar under the menu that offers to Recover what was autosaved (Troubleshooting › After a crash).

Without the window

An agent working headless looks at its work with doc_render_preview (the command view.render): the same picture craft3d-cli render makes. view.pick answers "what is at this pixel of that picture", as a click does in the window.

Next: Using a Jig.

This page on GitHub