LEVIATHANDocumentation

DOC 02WORKSPACES

World

The World (Alt+4) is the 3D simulation: a vehicle running live in one of nine underwater scenes, with its sensors, overlays and any parts or hulls you have added, drawn in up to four views at once. It is where LEVIATHAN opens, and where the rest of the application becomes visible: the vehicle's state feeds the Dashboard, parts from CAD Studio and hulls from the Hull workspace appear here as solid objects, and episodes and replays play back here.

World workspace in the Shipwreck scene: the BlueROV2 Heavy beside the wreck with its four DVL beams, the forward sonar fan and the USBL link drawn in the water; the telemetry readout at top left; and the Sensors tab on the right with live sensor chips.
Figure 2.1 The World at the Shipwreck scene, with the DVL beams, the forward sonar fan and the USBL link drawn in the water.

Layout

A session in the World Choose a scene and vehicle, enable sensors and overlays, simulate in one of four control modes, look through up to four views including camera, chase and sonar, and analyse the live state in the Dashboard. Choose Scene, vehicle nine scenes, nine vehicles Enable Sensors 13 sensors, 10 overlays Simulate Run station-keep, transit, dive, rollout Look Views up to four: camera, chase, sonar, top Analyse Dashboard live state and metrics
Figure 2.2 A typical session in the World, from choosing a scene to analysing the run.
  • Tool strip, left: Select, Move (W), Rotate (E), Scale (R), Snap, Play or Pause, Stop, and Frame the vehicle.
  • Toolbar, top: view settings, grid, Frame, then the Vehicle, Scene, Sensors, Overlays and Simulate menus and Play; at the right, screenshot, Lighting, the five view layouts and the guides.
  • Views, centre: one to four, each with a header holding its Camera and Display menus, Track vehicle, and Maximize.
  • Dock, right: Stage (the scene tree and the Property panel) and Sensors (live sensor output).

Mouse: left-drag orbits, middle- or right-drag (or Shift-drag) pans, the wheel zooms. Click a face of the view cube to turn to it.

Views and cameras

The layout buttons, or keys 1 to 5, choose Single view, Two views, side by side, Two views, stacked, One large + three or Four views. The four-view default shows Perspective, the vehicle's camera, Top and the forward sonar. Each project remembers its own layout.

World in the four-view layout: a perspective view of the vehicle at the wreck, the front camera with a heading tape, altitude and depth readouts, a top view of the seabed, and the forward sonar image as a fan of range arcs.
Figure 2.3 Four views: Perspective, the front camera, Top and the forward-looking sonar.

A view can look through any camera or sensor the vehicle declares, or follow it in a chase view.

Looking through the BlueROV2's front camera at the Shipwreck: a heading tape across the top reading 006 degrees, a pitch ladder, a centre crosshair, altitude 1.99 m at left and depth 5.42 m at right; Property shows the front camera sensor, type rgb_camera.
Figure 2.4 Front camera. Heading tape, pitch ladder, crosshair, altitude and depth.
Forward sonar view: a 120 degree fan out to 30 m with range rings and the seabed's returns drawn as bright arcs.
Figure 2.5 Forward sonar. The simulation service's sonar image, 120° to 30 m.
Chase view behind the BlueROV2 at the Shipwreck, with a compact telemetry card showing depth 5.61 m and an attitude ball.
Figure 2.6 Chase view: the camera follows the vehicle at a set distance and height.
Table 2.1 A view's Camera menu.
GroupEntries
ProjectionPerspective or orthographic
Standard viewsFront, Back, Left, Right, Top, Bottom and Isometric (Ctrl+1 to Ctrl+7), Dimetric, Trimetric, Normal To (Ctrl+8, on a picked face)
Look throughPerspective, Chase (distance and height), each declared camera, Forward sonar
Sonar viewRange 10, 20, 30, 50 or 80 m; gain; Ocean, Grayscale or Amber colour map; 10 or 5 Hz; Freeze
CameraField of view 15–110°, near and far clip, exposure, section plane
OtherSave view (up to 20), Frame selection (F), Frame all (A), Link camera, Copy view as PNG, Maximize
Display menu: display styles Shaded, Shaded with Edges, Wireframe, Hidden Lines Visible, Hidden Lines Removed, Clay, Unlit, Normals and Depth, and Show toggles for Grid, Axes, Sensor overlays, Trajectory, HUD, Environment effects and Selection outline.
Figure 2.7 Display menu. Nine styles, and what the view shows.
A view's Camera menu: Perspective, the standard views with Ctrl shortcuts, Look through Perspective, Chase, Front camera or Forward sonar, and camera field of view, near and far clip and exposure.
Figure 2.8 Camera menu.
Table 2.2 World toolbar menus.
MenuContents
VehicleChoose one of nine built-in vehicles; Upload CAD… (.glb, .gltf, .obj, .stl, .dae) with an axis convention; Import URDF / SDF / MJCF… to register a new vehicle
SceneOcean preset (the nine scenes), turbidity 0–100 %, sea state (significant wave height 0–4 m), current speed 0–2 m/s and heading; OpenUSD open and export
SensorsDVL, Sonar, Camera, LiDAR, Bathy, USBL, LBL, GPS, IMU, Depth, Compass, CTD and ADCP, all off until you turn them on
OverlaysGrid, Current, Velocity, Thrust, Buoyancy, Axes, Tether, Arm, Acoustic, Reef footprint
SimulateControl mode Station-keep, Transit, Dive or Rollout; multi-vehicle Fleet and Formation; buoyancy-driven Glide
LightingSun elevation and azimuth, exposure, brightness
View settingsNavigation speeds and inertia, selection colour, manipulator size and snap steps (0.1 m, 15°, 0.1), render scale, reset to defaults
Vehicle menu: the BlueROV2 selected, Upload CAD and Import URDF / SDF / MJCF buttons.Vehicle
Overlays menu: Grid and Current on; Velocity, Thrust, Buoyancy, Axes, Tether, Arm, Acoustic and Reef footprint off.Overlays
Simulate menu: Station-keep mode selected, with Fleet, Formation and Glide buttons.Simulate
Lighting popover: sun elevation 64 degrees, sun azimuth 39.8 degrees, exposure 0 EV, brightness 1.00.Lighting
The Scene menu open: the Shipwreck preset, turbidity 7 percent, sea state 0 m, current speed and heading sliders, and OpenUSD Open and Export buttons.
Figure 2.9 Scene menu: preset, water and current.
The Sensors menu open: a grid of toggles for DVL, Sonar, Camera, LiDAR, Bathy, USBL, LBL, GPS, IMU, Depth, Compass, CTD and ADCP, with DVL, Sonar, Bathy, USBL, IMU and Depth switched on.
Figure 2.10 Sensors menu: the thirteen payload toggles.

Stage and Property

Stage is the scene tree: World ▸ Environment (lights, water surface, water column, current, seabed, props), the vehicle with its links, joints, thrusters and sensors, Structures (your parts and hulls) and Missions (the rollout path and evaluated trajectories). Each row has visibility and lock toggles and a type. Filter chips narrow the tree to Lights, Vehicle, Thrusters, Sensors, Props or Structures; arrows, F2, F, H, Delete and Ctrl+A work on it; the context menu frames, isolates, hides, renames and copies the prim path.

Property, below it, shows the selection: name, prim path and a transform with colour-coded X, Y and Z fields that can be typed or dragged, with reset; for the vehicle, its live depth, altitude, heading, speed and thruster commands; for a sensor, its type, frame and a once-a-second live sample. Ctrl+Z undoes edits (up to 100 steps).

The vehicle selected in the World with the move gizmo on it; Stage lists the environment lights, water, seabed and wreck, then the BlueROV2 Heavy with its base link and thrusters T1 to T8; Property shows the vehicle's prim path and its position, rotation and scale fields.
Figure 2.11 The vehicle selected, with the move gizmo. Stage lists the scene and the vehicle's links, thrusters and sensors; Property shows its transform.

The Sensors tab

The Sensors tab shows each enabled sensor's output as you fly: a chip per sensor (Sonar, Bathy, USBL, LBL, GPS, DVL, IMU, Depth, Compass, CTD, ADCP, forward-looking sonar, LiDAR), and under it the reading and its coverage settings. See Sensors for what each one models.

Sensors tab, SONAR: a 38 degree forward sector drawn to 3.2 m with range, field of view and returns readouts and coverage sliders.Sonar: sector, range and returns.
Sensors tab, BATHY: a nadir profile with altitude 7.4 m, bottom 8.0 m and depth 0.6 m.Bathy: nadir profile.
Sensors tab, USBL: an acoustic fix plot with slant range 10.2 m, bearing 218 degrees and error 0.45 m.USBL: acoustic fix.
Sensors tab, DVL: bottom lock yes, altitude 0.8 m, range 2.6 m, and a coverage range slider.DVL: bottom lock.

Scenes and vehicles

The nine scenes are Coral Reef, Shipwreck, Pipeline, Ice / Under-Ice, Dam / Reservoir, Offshore oil rig, Pier / Quay, Ship Hull and Harbour; each sets its own seabed, water, current and sound speed (see Environments). The nine vehicles are two inspection ROVs, a work-class ROV, three AUVs, a hovering AUV, a surface vessel and a glider (see Vehicles).

Coral Reef scene: the vehicle among coral heads on a sandy seabed.
Figure 2.12 Coral ReefClear water, 18 m.
Shipwreck scene: the vehicle beside the hull of a wreck on a sandy shelf.
Figure 2.13 ShipwreckCoastal water, 24 m.
Pipeline scene: a flanged subsea pipeline with a valve and markers, and the vehicle above it.
Figure 2.14 Pipeline60 m, cross-current.
Offshore oil rig scene: the vehicle among the jacket structure in clear open water.
Figure 2.15 Offshore oil rigAbout 30 m, open water.

World assets

Parts from CAD Studio and hulls from the Hull workspace can be sent to the World as world assets. Each is placed at the first view's orbit target (a hull floats at its draft; other bodies rest on the seabed), appears under Stage ▸ Structures, can be moved, rotated, scaled and deleted, and is saved with the project.

World workspace in the Shipwreck scene: a torpedo-shaped hull exported from CAD Studio rests on the seabed beside the vehicle. The Stage panel lists it under Structures as Hull, and Property shows its position, rotation and scale.
Figure 2.16 A torpedo hull from CAD Studio placed in the Shipwreck scene.
  • Collision is generated as up to 32 convex pieces. Vehicles collide with them in simulation runs and live Worlds, and the World's sonar fan sees them.
  • Limits: 64 MiB per asset, 400,000 triangles, 64 assets per project.
What sees a world asset

The convex pieces are larger than the body, so a hollow part is treated as filled in. The service's own sensor models, the scientific camera and the learning environments do not yet see world assets.

Table 2.3 World shortcuts.
KeysAction
W, E, RMove, rotate, scale the selection
F, AFrame the selection, frame all
1 – 5View layouts
Ctrl+1 – Ctrl+8Standard views, Normal To
EscRestore a maximized view
Ctrl+ZUndo a scene edit

View ▸ Show Performance Stats adds frame rate, frame time, draw calls and triangles to each view. File ▸ Capture view as PNG saves the view.