HeightLimitAnalysis

A spatial analysis object for height-limit (excess-height detection) analysis, used to perform height-limit analysis on a 3D scene.

The parts exceeding limitHeight are highlighted with limitColor, reusing the water-surface rendering mechanism of FloodAnalysis (analysis type analysisType = 2).

Constructor

import { HeightLimitAnalysis } from '@maptalks/gl-layers';

const heightLimitAnalysis = new HeightLimitAnalysis({
  limitHeight: 25,
  limitColor: [1, 0.2, 0.2]
});

heightLimitAnalysis.addTo(groupGLLayer);

Details

Parameters:

• options* Object configuration options, the available options are as follows:

Option	Type	Description	Default
limitHeight*	Number	The height limit in meters	null
limitColor	Number[]	A 3-component normalized array; the color of the parts exceeding the limit (the source's DEFAULT_LIMIT_COLOR)	[0.8, 0.1, 0.1]
boundary	Number[]	Boundary coordinate ring of the analyzed area (optional; when not set, the whole scene is analyzed; inherited from FloodAnalysis)	null

Methods Inherited from FloodAnalysis

HeightLimitAnalysis inherits from FloodAnalysis (including options such as waterHeight, waterColor, waterOpacity, and methods such as update and renderAnalysis, verified against the 2026 source).

Methods Inherited from Analysis

addTo(groupGLLayer)

Adds the analysis object to a GroupGLLayer.

Spatial analysis objects can only be added to a GroupGLLayer; they cannot be added to other WebGL layers.

Parameters:

• groupGLLayer GroupGLLayer the GroupGLLayer

Returns:

• this

remove()

Removes the spatial analysis object from the layer.

Returns:

• void

update(name, value)

Updates options data.

Parameters:

• name String the setting name
• value any the setting value

Returns:

• void

getAnalysisType()

Gets the type of the Analysis.

Returns:

• String

getDefines()

Internal method.

Returns the defines added to the shader when the Analysis is rendered.

Returns:

• Object

renderAnalysis(meshes)

Internal method.

Renders the spatial analysis scene (implemented by each analysis subclass) and returns the uniform variables required for rendering.

Parameters:

• meshes Mesh[] the scene meshes

Returns:

• Object

enable()

Enables the analysis.

Returns:

• void

disable()

Disables the analysis.

Returns:

• void

isEnable()

Whether the analysis is enabled.

Returns:

• Boolean

getExcludeLayers()

Gets the list of layer ids excluded from the analysis (these layers are ignored during the analysis).

Returns:

• String[]

setExcludeLayers(layerIds)

Sets the list of layer ids excluded from the analysis.

Parameters:

• layerIds String[] list of layer ids

Returns:

• void

exportAnalysisMap(meshes)

Exports the analysis result image (RGBA pixel data); returns null when the analysis is not enabled.

Parameters:

• meshes Mesh[] the scene meshes

Returns:

• Uint8Array

This document has been cross-checked against the @maptalks/gl-layers 2026 source (api-notes-others.md / api-notes-vt-gl.md)