--- title: "TerrainTileManager | JavaScript maps SDK" description: "Documentation for MapTiler SDK" --- > For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL. # Class TerrainTileManager Methods mixed in to other classes for event capabilities. #### Hierarchy ([View Summary](https://docs.maptiler.com/sdk-js/api-reference/hierarchy/#Externals.TerrainTileManager)) - [Evented](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/) - TerrainTileManager ##### Index ### Constructors[](#constructors) [constructor](#constructor) ### Properties[](#properties) [deltaZoom](#deltazoom) [maxzoom](#maxzoom) [minzoom](#minzoom) [tileManager](#tilemanager) [tileSize](#tilesize) ### Methods[](#methods) [anyTilesAfterTime](#anytilesaftertime) [destruct](#destruct) [findTileInCaches](#findtileincaches) [fire](#fire) [freeRtt](#freertt) [getRenderableTiles](#getrenderabletiles) [getSource](#getsource) [getSourceTile](#getsourcetile) [getTerrainCoords](#getterraincoords) [getTileByID](#gettilebyid) [listens](#listens) [off](#off) [on](#on) [once](#once) [setEventedParent](#seteventedparent) [update](#update) ## Constructors[](#constructors-1) ### constructor[](#constructor) - new TerrainTileManager(tileManager: [TileManager](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.TileManager/)): TerrainTileManager[](#constructorterraintilemanager) #### Parameters - tileManager: [TileManager](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.TileManager/) #### Returns TerrainTileManager Overrides [Evented](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/).[constructor](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/#constructor) ## Properties[](#properties-1) ### deltaZoom[](#deltazoom) deltaZoom: number raster-dem tiles will load for performance the actualZoom - deltaZoom zoom-level. ### maxzoom[](#maxzoom) maxzoom: number maximum zoomlevel to render the terrain. ### minzoom[](#minzoom) minzoom: number minimum zoomlevel to render the terrain. ### tileManager[](#tilemanager) tileManager: [TileManager](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.TileManager/) tile manager for the raster-dem source. ### tileSize[](#tilesize) tileSize: number render-to-texture tileSize in scene. ## Methods[](#methods-1) ### anyTilesAfterTime[](#anytilesaftertime) - anyTilesAfterTime(time?: number): boolean[](#anytilesaftertime-1) gets whether any tiles were loaded after a specific time. This is used to update depth & coords framebuffers. #### Parameters - `Optional`time: number the time #### Returns boolean true if any tiles came into view at or after the specified time ### destruct[](#destruct) - destruct(): void[](#destruct-1) #### Returns void ### findTileInCaches[](#findtileincaches) - findTileInCaches(key: string): [Tile](https://docs.maptiler.com/sdk-js/api-reference/classes/Tile/) | undefined[](#findtileincaches-1) #### Parameters - key: string #### Returns [Tile](https://docs.maptiler.com/sdk-js/api-reference/classes/Tile/) | undefined ### fire[](#fire) - fire(event: string | [Event](https://docs.maptiler.com/sdk-js/api-reference/classes/Event/), properties?: any): this[](#fire-1) #### Parameters - event: string | [Event](https://docs.maptiler.com/sdk-js/api-reference/classes/Event/) - `Optional`properties: any #### Returns this Inherited from [Evented](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/).[fire](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/#fire) ### freeRtt[](#freertt) - freeRtt(tileID?: [OverscaledTileID](https://docs.maptiler.com/sdk-js/api-reference/classes/OverscaledTileID/)): void[](#freertt-1) Free render to texture cache #### Parameters - `Optional`tileID: [OverscaledTileID](https://docs.maptiler.com/sdk-js/api-reference/classes/OverscaledTileID/) optional, free only corresponding to tileID. #### Returns void ### getRenderableTiles[](#getrenderabletiles) - getRenderableTiles(): [Tile](https://docs.maptiler.com/sdk-js/api-reference/classes/Tile/)\[\][](#getrenderabletiles-1) get a list of tiles, which are loaded and should be rendered in the current scene #### Returns [Tile](https://docs.maptiler.com/sdk-js/api-reference/classes/Tile/)\[\] the renderable tiles ### getSource[](#getsource) - getSource(): [Source](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Source/)[](#getsource-1) #### Returns [Source](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Source/) ### getSourceTile[](#getsourcetile) - getSourceTile(     tileID: [OverscaledTileID](https://docs.maptiler.com/sdk-js/api-reference/classes/OverscaledTileID/),     searchForDEM?: boolean, ): [Tile](https://docs.maptiler.com/sdk-js/api-reference/classes/Tile/) | undefined[](#getsourcetile-1) find the covering raster-dem tile #### Parameters - tileID: [OverscaledTileID](https://docs.maptiler.com/sdk-js/api-reference/classes/OverscaledTileID/) the tile to look for - `Optional`searchForDEM: boolean Optional parameter to search for (parent) source tiles with loaded dem. #### Returns [Tile](https://docs.maptiler.com/sdk-js/api-reference/classes/Tile/) | undefined the tile ### getTerrainCoords[](#getterraincoords) - getTerrainCoords(     tileID: [OverscaledTileID](https://docs.maptiler.com/sdk-js/api-reference/classes/OverscaledTileID/),     terrainTileRanges?: { \[zoom: string\]: [CanonicalTileRange](https://docs.maptiler.com/sdk-js/api-reference/types/CanonicalTileRange/) }, ): [Record](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.Record/)[](#getterraincoords-1) Searches for the corresponding current renderable terrain-tiles #### Parameters - tileID: [OverscaledTileID](https://docs.maptiler.com/sdk-js/api-reference/classes/OverscaledTileID/) the tile to look for - `Optional`terrainTileRanges: { \[zoom: string\]: [CanonicalTileRange](https://docs.maptiler.com/sdk-js/api-reference/types/CanonicalTileRange/) } #### Returns [Record](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.Record/) the tiles that were found ### getTileByID[](#gettilebyid) - getTileByID(id: string): [Tile](https://docs.maptiler.com/sdk-js/api-reference/classes/Tile/)[](#gettilebyid-1) get terrain tile by the TileID key #### Parameters - id: string the tile id #### Returns [Tile](https://docs.maptiler.com/sdk-js/api-reference/classes/Tile/) the tile ### listens[](#listens) - listens(type: string): boolean[](#listens-1) Returns a true if this instance of Evented or any forwardeed instances of Evented have a listener for the specified type. #### Parameters - type: string The event type #### Returns boolean `true` if there is at least one registered listener for specified event type, `false` otherwise Inherited from [Evented](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/).[listens](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/#listens) ### off[](#off) - off(type: string, listener: [Listener](https://docs.maptiler.com/sdk-js/api-reference/types/Listener/)): this[](#off-1) Removes a previously registered event listener. #### Parameters - type: string The event type to remove listeners for. - listener: [Listener](https://docs.maptiler.com/sdk-js/api-reference/types/Listener/) The listener function to remove. #### Returns this Inherited from [Evented](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/).[off](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/#off) ### on[](#on) - on(type: string, listener: [Listener](https://docs.maptiler.com/sdk-js/api-reference/types/Listener/)): [Subscription](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Subscription/)[](#on-1) Adds a listener to a specified event type. #### Parameters - type: string The event type to add a listen for. - listener: [Listener](https://docs.maptiler.com/sdk-js/api-reference/types/Listener/) The function to be called when the event is fired. The listener function is called with the data object passed to `fire`, extended with `target` and `type` properties. #### Returns [Subscription](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Subscription/) Inherited from [Evented](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/).[on](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/#on) ### once[](#once) - once(type: string, listener?: [Listener](https://docs.maptiler.com/sdk-js/api-reference/types/Listener/)): Promise | TerrainTileManager[](#once-1) Adds a listener that will be called only once to a specified event type. The listener will be called first time the event fires after the listener is registered. #### Parameters - type: string The event type to listen for. - `Optional`listener: [Listener](https://docs.maptiler.com/sdk-js/api-reference/types/Listener/) The function to be called when the event is fired the first time. #### Returns Promise | TerrainTileManager `this` or a promise if a listener is not provided Inherited from [Evented](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/).[once](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/#once) ### setEventedParent[](#seteventedparent) - setEventedParent(parent?: [Evented](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/) | null, data?: any): this[](#seteventedparent-1) Bubble all events fired by this instance of Evented to this parent instance of Evented. #### Parameters - `Optional`parent: [Evented](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/) | null - `Optional`data: any #### Returns this Inherited from [Evented](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/).[setEventedParent](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Evented/#seteventedparent) ### update[](#update) - update(transform: [ITransform](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Externals.ITransform/), terrain: [Terrain](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Terrain/)): void[](#update-1) Load Terrain Tiles, create internal render-to-texture tiles, free GPU memory. #### Parameters - transform: [ITransform](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Externals.ITransform/) the operation to do - terrain: [Terrain](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.Terrain/) the terrain #### Returns void