Using the Visualizer

Prev: Part 2: Installation

PyMFCAD includes a browser-based visualizer for inspecting and validating devices. You will use it throughout the tutorial to confirm geometry, labeling, ports, and routing.

Step 1 — Launch the visualizer

From your project directory, run:

pymfcad

Or, if using uv:

uv run pymfcad

This command starts a local web server. If the page does not open automatically, go to http://127.0.0.1:8000/ in your browser. To stop the server, press Enter in the terminal where it is running.

Step 2 — Load Settings dialog (first screen)

When the visualizer opens, you will see the Load Settings dialog. This controls what data is loaded and how the preview is prepared.

At a high level, this dialog lets you:

• Load settings from model and/or from seperate settings file
• Control what settings are loaded into the scene from each file
• Load Selected settings

When finish, the settings dialog can be closed with the Close button, or by clicking off the pane.

Step 3 — General layout overview

The visualizer layout is organized around four main regions:

• Toolbar (bottom center) — common actions like snapshots and camera controls
• View cube (top right) — tool for quick orientation allowing snaping to faces, edges, or corners
• Model selector (top right) — visibility and category controls for models and overlays
• Auto Reload button (bottom right) — enables or disables auto reloading of models

Step 4 — Keyboard and mouse controls

The visualizer supports two control styles: Orbit and Trackball (selectable in Settings → Camera). Common controls:

• F11 — toggle fullscreen in the browser.
• Double‑click the model — sets the camera target to the clicked surface (raycast to visible geometry).

Orbit controls

• Mouse
  • Right‑click drag — orbit
  • Left‑click drag — pan
  • Scroll wheel / middle mouse — zoom
  • Hold Shift or Ctrl to swap orbit ↔ pan behavior
• Keyboard
  • Arrow keys — rotate
  • Arrow keys + Shift or Ctrl — pan

Trackball controls

• Mouse
  • Right‑click drag — orbit
  • Left‑click drag — pan
  • Hold A to orbit, S to zoom, D to pan
• Keyboard
  • Arrow keys + A — orbit
  • Arrow keys + S — zoom (Up/Down) and roll (Left/Right)
  • Arrow keys + D — pan

Step 5 — Model selector (overview)

The Model Selector controls visibility for the main geometry and overlays. Each group has a master toggle (e.g., Device) and may have more sub-toggles for specific content.

Device

• Device — final bulk-minus-void geometry, used for export and slicing

Bounding box

• Bounding Box — black outline of the device bounds

Unconnected ports

• Unconnected Ports — helper overlay showing unconnected port size, position, and type (green: IN, red: OUT, blue: IN/OUT)

Bulk

• Bulk — all bulk shapes before void subtraction

Voids

• Voids — all void shapes

• Fluidic Subcategory — only voids labeled with fluidic for focused inspection

Regional settings overlays

• Regional — visual overlays for regional settings (not part of final geometry)

Step 6 — Toolbar (overview)

The Toolbar is divided into two sections: Camera Controls and Tools.

Camera controls

• Home — returns the camera to the home position and clears any selected saved camera position or animation frame (advanced topic).
• Add saved camera position — adds a new saved position. When a saved position is clicked, the camera moves to that viewpoint.

• The active saved position can be updated with the current camera view by clicking the Update Camera button.

Tools

• Documentation — opens the local version of this site.
• Snapshot — captures an image of the current view.
• Animation — advanced topic (covered later in Extra 7: Advanced Visualizer Topics).
• Settings — opens the settings panels.

Step 7 — Settings panels (advanced topic)

The visualizer includes detailed settings panels for rendering and navigation. These are covered in Extra 7: Advanced Visualizer Topics:

• General settings
• Appearance settings
• Camera settings
• Light settings

Quick checks before moving on

• You can open the Load Settings dialog and load a preview.
• You can identify the overview, toolbar, view cube, model selector, and reload controls.
• You understand the purpose of each model selector group.

With this overview, you should be ready to begin designing your own devices.

Next: Part 4: Creating Your First Component