DOC 03SIMULATION CONTENT

Environments

LEVIATHAN ships nine scenes, chosen from Scene → Ocean preset in the Viewport. Each one pairs a detailed 3D structure model, which you see and the cameras image, with an analytic environment that sets the depth, water, current and acoustics the physics and sensors use.

Gallery

Coral Reef scene: scanned coral formations on a sandy seabed. — **Coral Reef**

Shipwreck scene: the scanned hull of the MV Panagiotis wreck in clear blue water. — **Shipwreck**

Pipeline scene: a flanged pipeline crossing the seabed toward a manifold. — **Pipeline**

Ice / Under-Ice scene: an ice keel seen from below the canopy. — **Ice / Under-Ice**

Dam / Reservoir scene: the face of a gravity dam rising from turbid water. — **Dam / Reservoir**

Offshore oil rig scene: a fixed-jacket platform standing in open water. — **Offshore oil rig**

Pier / Quay scene: two scanned timber piers either side of a channel. — **Pier / Quay**

Ship Hull scene: the side of the icebreaker hull seen from below the waterline, above a sandy seabed. — **Ship Hull**

Harbour scene seen from above the water: a mountainous island with quays, a dock basin and moored ships. — **Harbour**

The gallery shows each scene as first loaded, with the BlueROV2 as the vehicle; the Harbour is shown from above the water to give a sense of its scale. The scene sections below pair several scenes with the vehicle class they suit. All images are Viewport captures from the current release.

Scene characteristics

Table 3.1 What each scene sets when it is selected in the Viewport, and the analytic environment behind it. Current speed and heading are the Viewport preset values, which you can change afterwards; seabed depth, water class and sound speed come from the analytic preset.
Scene	Seabed	Water	Current	Turbidity	Tide	Sound speed
Coral Reef	18 m	Clear	0.11 m/s · 75°	10 %	None	1502 m/s
Shipwreck	24 m	Coastal	0.09 m/s · 20°	7 %	None	1500 m/s
Pipeline	60 m	Coastal	0.22 m/s · 60°	45 %	None	thermocline
Ice / Under-Ice	30 m	Clear	0.05 m/s · 90°	20 %	None	1450 m/s
Dam / Reservoir	38–72 m	Turbid	0.03 m/s · 0°	55 %	None	1447 m/s
Offshore oil rig	30 m^*	Clear	0.25 m/s · 90°	8 %	None	Not specified
Pier / Quay	9 m	Coastal	0.18 m/s · 60°	45 %	0.2 m/s, 720 s	coastal
Ship Hull	14 m	Coastal	0.05 m/s · 90°	35 %	None	1500 m/s
Harbour	12 m	Turbid	0.21 m/s · 75°	35 %	0.3 m/s, 600 s	1505 m/s

^* Water depth recorded with the oil-rig structure model; the scene uses the Viewport's open-water environment rather than a dedicated analytic preset. Tidal currents are short-period oscillations so that they are visible within an episode. Sound speeds marked by profile name use the profiles described in Ocean and environment.

Two representations of one scene

The structure model is a detailed triangle mesh. The Viewport draws it, and the PerceptionFrame camera and canonical sensors image it when its geometry is part of the snapshot. The analytic environment gives the physics and the analytic sensors a seabed, a current, tides and simplified stand-ins for structures, such as obstacle footprints and shoals. A vehicle's dynamics do not collide with the detailed mesh.

The scenes

Coral Reef

A REMUS-100-class AUV passing between two scanned coral heads with sea fans and coloured corals on a sandy bottom. — Figure 3.1 Coral Reef: a REMUS-100-class AUV between scanned coral heads.

A shallow reef in clear water: rugged bathymetry with three coral-head shoals, a light current and a gentle eddy (0.3 m/s at 10 m radius). The structure is a scanned reef model about 19 m by 18 m. Use it for close-range inspection, obstacle avoidance among irregular natural geometry, and clear-water imaging. The Reef footprint overlay shows the area the reef occupies.

Shipwreck

A BlueROV2 Heavy beside the graffiti-covered hull of the MV Panagiotis, with broken plating on the sandy seabed in the foreground. — Figure 3.2 Shipwreck: a BlueROV2 Heavy alongside the scanned MV Panagiotis, about 47 m long.

A wreck survey site on a shelf bottom with a weak set across it. The structure is a photogrammetric scan of the MV Panagiotis on Zakynthos (Zante), roughly 47 m long, 7.7 m in beam and 6.4 m high. The analytic environment represents a hull broken amidships with a debris field as obstacle footprints. Use it for wreck survey patterns, sonar and camera data over complex man-made geometry, and the sensor footprints shown in Sensors.

Pipeline

A HUGIN-class AUV flying low along a subsea flowline with a flange joint, marker posts and a concrete support. — Figure 3.3 Pipeline: a HUGIN-class AUV following the flowline. The work site also has a manifold, valves, a crossing, anodes, damage, a leak and markers.

A pipeline survey in 60 m of water with a steady cross-current. The work site, about 36 m by 24 m, uses one layout shared by the scene, the sonar and the learning task. Use it for pipeline following, inspection of anodes and valves, and defect search.

Ice / Under-Ice

A hovering AUV in bright blue water below the ice canopy, with the edge of a pressure-ridge keel at the right. — Figure 3.4 Ice / Under-Ice: a hovering AUV below the canopy, beside a pressure-ridge keel.

Under-ice operations in clear water: a thin ice canopy pierced by pressure-ridge keels that dip into the water column. The vehicle has to keep clearance below the ice and dive under each ridge. The structure is a coastal sea-ice model about 250 m across. Use it for under-ice transit and for sensors that look up as well as down.

Dam / Reservoir

Dam scene: the curved concrete face of a large gravity dam disappearing into green-blue turbid water. — Figure 3.5 Dam / Reservoir: impounded, silty water against a gravity dam.

An impounded reservoir against a gravity dam. The water is still, with no tide, and turbid with suspended silt. The bed shelves from 72 m at the dam face to 38 m at the back shore. The structure is a model of the Hoover Dam, with the wall rebuilt where the source model left gaps. Use it for dam-face inspection in poor visibility.

Offshore oil rig

A work-class ROV hovering among the legs and horizontal bracing of the platform jacket, with light caustics on the seabed. — Figure 3.6 Offshore oil rig: a work-class ROV inside the jacket, in about 30 m of water.

A fixed-jacket platform in open water with a shelf current and clear water. The structure, about 58 m by 62 m in plan, extends from the seabed through the surface to the topside. Use it for jacket and riser inspection, and for scenes where the surface and the structure appear together.

Pier / Quay

A BlueROV2 hovering in front of a dense row of scanned timber piles. — Figure 3.7 Pier / Quay: a BlueROV2 in front of the scanned timber piles.

Quay-wall and pile inspection in 9 m of coastal water, with a moderate cross-current and a tidal oscillation. The structure is a scan of two piers across a channel, about 48 m by 69 m. In the analytic environment, a shoal stands in for the vertical structure. Use it for pile inspection and close manoeuvring between structures.

Ship Hull

Hull inspection in near-still water alongside a large floating body. The structure is a shallow-draft icebreaker about 84 m long, afloat at the surface. The analytic environment represents the hull as a broad overhead shoal. Use it for in-water hull inspection; for fouling and cleaning analysis, see the Hull workspace.

Harbour

A shallow, turbid, tidal port. There is a weak mean current plus a tidal oscillation, and murky water limits optical range. The harbour has realistic bathymetry: dredged berths, an approach channel, and a shelf falling to 45 m. The Viewport's seabed, altimeter and scripted vehicle follow this depth grid. The vehicle starts beside a moored vessel with cranes. Use it for berth and quay inspection, and for navigation in confined, poorly lit water.

Changing the environment

After choosing a preset, the Scene menu adjusts turbidity, sea state (significant wave height) and the current's speed and heading. The Current overlay draws the flow field. The Dashboard offers deeper control: the Ocean field and Sound-speed profile panels, real bathymetry import with Import bathymetry, and the Tide panel for water level. See Ocean and environment.

Limitations

Scene models are third-party scans and artistic models. Their shapes are real, but their surfaces carry display colours, not measured optical reflectance or acoustic material properties.
Analytic environments stand in for structures with simplified footprints, so the physics sees an approximation of the scene geometry.
Each scene's water is homogeneous for the camera model. Stratified optical properties are not modelled.