Oceanology Next-Gen — RVT (Runtime Virtual Texture)

Last updated: 2025-12-13

Prerequisites

• Unreal Engine 5.5 or newer.
• Oceanology installed and configured (see the Setup page).
• A Landscape actor in your level for terrain-water interaction.
• Runtime Virtual Texturing enabled in Project Settings.
• Basic familiarity with Virtual Textures and Materials in Unreal Engine.

Notes

• The RVT (Runtime Virtual Texture) system in Oceanology enables seamless blending between water and terrain. It captures heightmap data from your landscape and uses it to create smooth shoreline transitions, proper depth-based effects, and accurate water-terrain intersections.
• RVT eliminates harsh water edges by sampling the actual terrain height at runtime, allowing the water shader to know exactly where land meets water.
• The system requires both the OceanologyManager (for heightmap capture setup) and the OceanologyInfiniteOcean (for RVT rendering settings) to be properly configured.

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Step-by-step

1. Add the Oceanology Manager to your scene

Open your level and use the Quickly Add to the Project menu (the + button in the toolbar or right-click in the viewport). Type Oceanology in the search field to filter the available actors.

Locate and add the following actor:

• Oceanology Manager — The central controller that manages RVT heightmap capture and other Oceanology systems.

The Manager is essential for RVT functionality as it handles the heightmap generation from your landscape. Without it, the water will not have terrain depth information for proper shoreline rendering.

Other useful actors visible in the menu:

• Oceanology Infinite Ocean — The main ocean water body.
• Oceanology Lake — Bounded water body for lakes.
• Oceanology Water Volume — Interaction volume for buoyancy and effects.

2. Configure the Oceanology Manager for RVT

Select the OceanologyManager actor in your level. In the Details panel, you will find the RVT-related configuration sections:

Transform:

• Location — Position of the manager actor. Example: -100800.0, -100800.0, -100.0
• Scale — Defines the capture area size. Example: 201600.0, 201600.0, 15089.843. This should cover your entire landscape.

Heightmap:

• Setup Landscape/Ground Mesh — Click this button to automatically configure the heightmap capture based on your landscape. This is the quickest way to set up RVT.

RVT Settings:

• Auto Configure Functions — ✅ Enabled. Automatically sets up RVT capture functions.
• Auto Configure Heightmap Location and Scale — ✅ Enabled. Automatically positions and scales the heightmap capture to match your landscape bounds.
• Auto Configure Water Z — ✅ Enabled. Automatically determines the water surface Z height.

Volume Bounds:

• Bounds Align Actor — Landscape. Select the landscape actor to align the capture volume.
• Set Bounds — Click to manually set the capture bounds if auto-configure doesn't produce desired results.

Advanced:

• Snap To Landscape — When enabled, snaps the manager to the landscape surface.
• Expand Bounds — 0.0. Adds padding to the capture bounds.

3. Configure RVT settings on the Ocean actor

Select the OceanologyInfiniteOcean actor in your level. In the Details panel, locate and expand the RVT category:

RVT Parameters:

• WaterZMin — -100.0. The minimum Z height for water rendering. Water below this level will not render RVT effects.
• HeightmapLocation — Vector defining the world position of the heightmap capture origin. Displayed as a blue color picker for X/Y coordinates.
• HeightmapScale — Vector defining the scale/size of the heightmap capture area. Displayed as a yellow color picker.
• WaterBoxScale — Vector defining the water rendering box dimensions. Displayed as a dark color picker.

Heightmap Asset:

• RVT_Heightmap — RVT_Heightmap. The Runtime Virtual Texture asset that stores the captured heightmap data. This texture is sampled by the water material to determine terrain depth.

The heightmap preview shows a grayscale representation of your terrain — white areas are high elevation, black areas are low. This data drives the water depth calculations and shoreline blending.

4. Understand the RVT Material setup

The RVT system works through a material setup that captures terrain data and outputs it to a Runtime Virtual Texture. Open the M_Grid material (or your landscape material) to see how heightmap data flows:

Heightmap Data Node:

• Absolute World Position (Excluding Material Offsets) — Provides the world position for height sampling.
• Input Data — The heightmap input connection.
• XYZ — Full 3D position output.
• XY — Horizontal position only.
• Z — Vertical height value (most important for water depth).

Runtime Virtual Texture Output: This node writes data to the RVT for the water shader to sample:

• BaseColor — Surface color information.
• Specular — Specular reflection data.
• Roughness — Surface roughness values.
• Normal — Surface normal vectors.
• WorldHeight — The terrain height at each point (critical for water depth).
• Opacity — Transparency information.
• Mask — General purpose masking.
• Displacement — Vertex displacement data.
• Mask4 — Additional mask channel.

The Z output from Heightmap Data connects to WorldHeight on the RVT Output. This is how the water shader knows the terrain elevation at every point, enabling proper depth-based coloring and shoreline blending.

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RVT Output Channels Reference

Channel	Purpose	Used By Water For
WorldHeight	Terrain elevation	Depth calculation, shoreline blending
BaseColor	Terrain color	Underwater terrain tinting
Normal	Surface normals	Caustic projection alignment
Roughness	Surface roughness	Wetness effect intensity
Mask	Custom masking	Foam generation, effect zones
Opacity	Transparency	Water edge softness

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Configuration Guidelines

Scenario	Recommended Settings
Quick setup	Click "Setup Landscape/Ground Mesh" on Manager
Large landscapes	Increase Manager Scale to cover entire terrain
Multiple landscapes	Position Manager at center, expand bounds
Custom shorelines	Adjust WaterZMin on Ocean actor
Performance optimization	Reduce RVT resolution in Project Settings
Sharp water edges	Verify HeightmapScale matches landscape bounds

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Troubleshooting Common Issues

Problem	Likely Cause	Solution
No shoreline blending	RVT not configured	Click "Setup Landscape/Ground Mesh" on Manager
Water ignores terrain	RVT_Heightmap not assigned	Verify RVT_Heightmap is set on Ocean actor
Incorrect depth colors	HeightmapLocation/Scale mismatch	Enable Auto Configure options on Manager
Harsh water edges	WaterZMin too low	Increase WaterZMin value
RVT not updating	Virtual Texturing disabled	Enable in Project Settings > Rendering
Heightmap appears blank	Landscape material missing RVT output	Add Runtime Virtual Texture Output to landscape material
Performance issues	RVT resolution too high	Reduce virtual texture size in Project Settings
Water floating above terrain	WaterZMin too high	Lower WaterZMin value

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Summary

In this guide, you learned how to:

1. Add the Oceanology Manager — Place the manager actor that handles RVT heightmap capture.
2. Configure Manager RVT settings — Set up automatic heightmap capture aligned to your landscape.
3. Configure Ocean RVT settings — Adjust heightmap location, scale, and the RVT texture reference.
4. Understand the Material setup — See how heightmap data flows from terrain to the Runtime Virtual Texture Output.

With RVT properly configured, your ocean will seamlessly blend with the terrain, showing accurate depth-based coloring, smooth shoreline transitions, and proper water-land intersections without harsh edges.