The TerrainData class stores heightmaps, detail mesh positions, tree instances, and terrain texture alpha maps.
The Terrain component links to the terrain data and renders it.
| alphamapHeight | Height of the alpha map. | 
| alphamapLayers | Number of alpha map layers. | 
| alphamapResolution | Resolution of the alpha map. | 
| alphamapTextures | Alpha map textures used by the Terrain. Used by Terrain Inspector for undo. | 
| alphamapWidth | Width of the alpha map. | 
| baseMapResolution | Resolution of the base map used for rendering far patches on the terrain. | 
| bounds | The local bounding box of the TerrainData object. | 
| detailHeight | Detail height of the TerrainData. | 
| detailPrototypes | Contains the detail texture/meshes that the terrain has. | 
| detailResolution | Detail Resolution of the TerrainData. | 
| detailWidth | Detail width of the TerrainData. | 
| heightmapHeight | Height of the terrain in samples (Read Only). | 
| heightmapResolution | Resolution of the heightmap. | 
| heightmapScale | The size of each heightmap sample. | 
| heightmapWidth | Width of the terrain in samples (Read Only). | 
| size | The total size in world units of the terrain. | 
| splatPrototypes | Splat texture used by the terrain. | 
| thickness | The thickness of the terrain used for collision detection. | 
| treeInstanceCount | Returns the number of tree instances. | 
| treeInstances | Contains the current trees placed in the terrain. | 
| treePrototypes | The list of tree prototypes this are the ones available in the inspector. | 
| wavingGrassAmount | Amount of waving grass in the terrain. | 
| wavingGrassSpeed | Speed of the waving grass. | 
| wavingGrassStrength | Strength of the waving grass in the terrain. | 
| wavingGrassTint | Color of the waving grass that the terrain has. | 
| GetAlphamaps | Returns the alpha map at a position x, y given a width and height. | 
| GetDetailLayer | Returns a 2D array of the detail object density in the specific location. | 
| GetHeight | Gets the height at a certain point x,y. | 
| GetHeights | Get an array of heightmap samples. | 
| GetInterpolatedHeight | Gets an interpolated height at a point x,y. | 
| GetInterpolatedNormal | Get an interpolated normal at a given location. | 
| GetSteepness | Gets the gradient of the terrain at point (x,y). | 
| GetSupportedLayers | Returns an array of all supported detail layer indices in the area. | 
| GetTreeInstance | Get the tree instance at the specified index. It is used as a faster version of treeInstances[index] as this function doesn't create the entire tree instances array. | 
| RefreshPrototypes | Reloads all the values of the available prototypes (ie, detail mesh assets) in the TerrainData Object. | 
| SetAlphamaps | Assign all splat values in the given map area. | 
| SetDetailLayer | Sets the detail layer density map. | 
| SetDetailResolution | Set the resolution of the detail map. | 
| SetHeights | Set an array of heightmap samples. | 
| SetHeightsDelayLOD | Set an array of heightmap samples. | 
| SetTreeInstance | Set the tree instance with new parameters at the specified index. However, TreeInstance.prototypeIndex and TreeInstance.position can not be changed otherwise an ArgumentException will be thrown. | 
| hideFlags | Should the object be hidden, saved with the scene or modifiable by the user? | 
| name | The name of the object. | 
| GetInstanceID | Returns the instance id of the object. | 
| ToString | Returns the name of the GameObject. | 
| Destroy | Removes a gameobject, component or asset. | 
| DestroyImmediate | Destroys the object obj immediately. You are strongly recommended to use Destroy instead. | 
| DontDestroyOnLoad | Makes the object target not be destroyed automatically when loading a new scene. | 
| FindObjectOfType | Returns the first active loaded object of Type type. | 
| FindObjectsOfType | Returns a list of all active loaded objects of Type type. | 
| Instantiate | Clones the object original and returns the clone. | 
| bool | Does the object exist? | 
| operator != | Compares if two objects refer to a different object. | 
| operator == | Compares two object references to see if they refer to the same object. |