TerrainGraph

A node-based procedural terrain heightmap generation tool for Unity. TerrainGraph provides a visual graph editor where nodes are connected to build complex terrain generation pipelines, with all heightmap processing running on the GPU via compute shaders for real-time preview feedback.

Features

• Visual node graph editor built on Unity GraphToolkit
• GPU-accelerated heightmap processing via HLSL compute shaders
• Real-time preview of each node's output in the editor
• Spline-based terrain shaping tools
• Export to Unity TerrainData, textures, and meshes
• Topological graph execution with dependency-aware caching

Node Reference

Generate

Nodes that produce heightmaps or splines from scratch.

Height

Node	Description
Constant	Flat heightmap at a fixed value
Gradient	Height that varies across the map using a configurable gradient ramp
Perlin Noise	Perlin noise heightmap with configurable frequency, offset, and seed
Voronoi Noise	Voronoi cell-based heightmap with configurable frequency and seed
Value Noise	Simple gradient noise heightmap
Grid Noise	Grid-pattern noise heightmap
Radial Shape	Height based on distance from a center point, with configurable shape type
Slope	Height that varies along a configurable direction
Islands	Procedural island landmass shapes
Spline Height	Height influenced by proximity to a spline
Spline Voronoi	Voronoi pattern generated along a spline path
Spline Radial	Radial height falloff emanating from a spline
Spline Ridge	Ridge or mountain shape along a spline path
Spline Curvature	Height derived from the curvature of a spline

Spline

Node	Description
Circle	Circular spline with configurable radius, arc angle, and vertex count
Curve	Spline drawn from preset curve shapes
Contour	Extracts a height contour line from a heightmap at a given level
Multi Contour	Extracts multiple contour lines from a heightmap at specified levels
Select	Selects a single spline from a spline list by index

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Modify Height

Nodes that take one or more heightmaps as input and produce a modified heightmap.

Arithmetic / Blending

Node	Description
Add	Adds a constant value or a second heightmap
Average	Averages with a constant value or a second heightmap
Compare	Outputs -1, 0, or 1 depending on value of a constant value or a second heightmap
Divide	Divides by a constant value or a second heightmap
Maximum	Selects the maximum of a constant value or a second heightmap
Minimum	Selects the minimum of a constant value or a second heightmap
Multiply	Multiplies by a constant value or a second heightmap
Subtract	Subtracts a constant value or a second heightmap

Other Math

Node	Description
Absolute	Takes the absolute value of each height
Clamp	Clamps values to a configurable [min, max]
Power	Raises values to a configurable exponent

Remapping

Node	Description
Bias	Applies a bias curve to skew height values toward 0 or 1
Gain	Applies a gain curve to push height values toward the extremes or center
Mask	Converts the heightmap to a mask by setting any non-zero values to 1
Normalize	Remaps the heightmap range to [0, 1]
Ramp	Uses a gradient or animation curve to remap height values
Range	Remaps the heightmap range to a configurable [min, max]
Rebase	Shifts the base of the height range
Step	Applies a threshold step function to the height values

Processing

Node	Description
Blur	Gaussian blur with configurable radius and iteration count
Invert	Flips height values around a specified center value
Terrace	Creates a terraced, stepped effect with configurable step size and smoothness
Relax	Laplacian smoothing that averages each point with its neighbors
Grow	Expands a region of height values to cover more surface area
Lift	Raises height values using an easing curve within a spline-defined region
Erosion	Particle-based erosion that simulates individual water droplets traveling downslope, carrying and depositing sediment with configurable inertia, erosion rate, and deposition rate

Transform

Node	Description
Translate	Offsets the heightmap by X/Y percentage
Rotate	Rotates the heightmap by a given angle
Scale	Scales (zooms) the heightmap
Resize	Changes the heightmap resolution with configurable interpolation

Single Layer

Node	Description
Replace	Replaces values in a single height layer
Remove	Zeros out a single height layer
Isolate	Zeros out everything other than a single height layer

Utility

Node	Description
Stamp	Stamps a heightmap pattern onto a base heightmap, with optional mask and configurable easing

Invariant

Node	Description
Preview	Pass-through node for inserting a preview point mid-graph without affecting values

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Modify Spline

Nodes that take a spline as input and produce a modified spline.

Node	Description
Smooth	Smooths sharp angles in a spline over configurable iterations
Resample	Changes the vertex density of a spline
Slice	Extracts a segment of a spline by start and end index
Splice	Combines multiple splines from a spline list into one
Displace	Displaces spline vertices along a direction
Open / Close	Toggles whether the spline is open or closed

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Import

Node	Description
Import Texture	Imports a Texture2D asset as a heightmap
Import Spline	Imports a spline from a scene object

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Export

Export nodes have no output port. They write data to external assets or files when the graph executes.

Node	Description
Export Terrain	Writes the heightmap to a Unity TerrainData asset
Export Texture	Saves the heightmap as a PNG or EXR texture asset
Export Mesh	Generates and saves a mesh asset from the heightmap
Export Spline	Exports spline vertex data to a file
Export Stamp	Applies the heightmap to a MicroVerse stamp

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How It Works

Nodes are connected in a directed acyclic graph. When any node's parameters or connections change, the graph re-evaluates in topological order — upstream nodes first — so each node always receives up-to-date inputs. Results are cached per-node and invalidated only when inputs change, keeping re-evaluation fast.

All heightmaps are stored as GPU RenderTextures and processed via HLSL compute shaders. This means even complex multi-node graphs with large resolutions update in real time in the editor.

Data Types

• HeightGrid — a heightmap stored as a floating-point RenderTexture
• SplineWrapper — a single spline curve
• SplineListWrapper — a collection of splines (e.g. contour lines)

Example Pipeline

Perlin Noise → Blur → Normalize → Stamp (with mask) → Relax → Export Terrain

1. Perlin Noise generates a base heightmap
2. Blur smooths the raw noise
3. Normalize remaps the range to [0, 1]
4. Stamp layers a detail pattern onto the terrain using a mask
5. Relax applies a final smoothing pass
6. Export Terrain writes the result to a Unity TerrainData asset