Use the active Object contained in a ObjectGroup to create a 2D or 3D partition grid displaying only the elements visible from an arbitrary viewer.

See Also

Static Variables

Name	Description
`group`	The ObjectGroup where the active ObjectGrid is defined.
Declaration ObjectGroup *group
`cell_type`	The type of cell that is used to split the ObjectGrid (see CellType).
Declaration CellType cell_type
`cell_size`	Size of each individual ObjectCell (usually represented in meters).
Declaration unsigned short cell_size
`cell_count`	Total amount of ObjectCell contained in the active ObjectGrid.
Declaration unsigned int cell_count
`viewer`	Reference to an arbitray Object to use as the grid viewer.
Declaration Object *viewer Note The viewer Object reference cannot be part of any ObjectGroup.

Variables

Name	Description
`viewer_method`	The active ViewerMethod use to determine which grid cells are visible.
Declaration ViewerMethod viewer_method
`viewer_angle`	The field of view of the viewer in degrees.
Declaration float viewer_angle
`viewer_height`	The height of the viewer.
Declaration float viewer_height
`viewer_distance`	Determine how far the viewer can see.
Declaration float viewer_distance

Functions

Name	Description
`Clear`	Clear the active ObjectGrid.
Declaration void Clear( bool restore ) Parameters `restore`: Place back all Object into the active Scene. Warning If restore is set to `false` the Object stored locally on disk will be permanently deleted.
`GetObjectCellAt`	Retrieve a specific ObjectCell from the current ObjectGrid using its coordinate as key.
Declaration ObjectCell GetObjectCellAt( const ivec3 coord, const bool auto_build ) Parameters* `coord`: The XYZ coordinate of the ObjectCell to retrieve. `auto_build`: If the ObjectCell does not already exists force its creation. Return Value `nil` if the `coord` does not match any ObjectCell contained in the active ObjectGrid; else return a reference to the ObjectCell matching the `coordinate` received in parameter.
`SetViewer`	Set the Object to be used as viewer for the active ObjectGrid.
Declaration int SetViewer( Object viewer, const ViewerMethod viewer_method, const const float viewer_angle, const float viewer_height, const float viewer_distance ) Parameters* `viewer`: Reference to the Object to use as viewer. Set `nil` to disconnect it. `viewer_method`: The ViewerMethod strategy to use to visualize the ObjectGrid. `viewer_angle`: The field of view of the viewer. `viewer_height`: The height of the viewer. `viewer_distance`: Clip end distance of the viewer. Return Value Return `0` if viewer is successfully set; `-1` if the viewer Object reference is associated to an existing ObjectGroup. `-2` if the Object does belong to the same Scene as the ObjectGroup associated to the active ObjectGrid.
`GetObjectIndex`	Build (or rebuild) the active ObjectGrid.
Declaration unsigned int Build( const CellType cell_type, const unsigned short cell_size ) Parameters `cell_type`: The type of cell to use for partitioning. `cell_size`: The size of each individual ObjectCell. Return Value The total amount of ObjectCell created.
`AddObject`	Add a specific Object reference to the active ObjectGrid.
Declaration int AddObject( Object object ) Parameters* `object`: Reference to an Object to include in the active ObjectGrid. Return Value `0` if the Object have successfully been inserted in the active ObjectGrid. `-1` if the Object reference is set to `nil`. `-2` if the Object does not belong to the ObjectGroup associated with the active ObjectGrid. `-3` if the Object is already part of the current ObjectGrid.
`UpdateObject`	Update the occupation data associated to a specific Object reference.
Declaration int UpdateObject( Object object ) Parameters* `object`: Reference to the Object to update. Return Value See ObjectGrid.AddObject for the values returned for this function.
`RemoveObject`	Remove an Object from the active ObjectGrid using its unique ID as key.
Declaration bool RemoveObject( const unsigned int object ) Parameters `object`: Unique identifier of the Object. Return Value `true` if the Object have been removed successfully; else return `false`.
`RemoveUnusedObjects`	Deselect all Object contained in the active ObjectGrid.
Declaration unsigned int RemoveUnusedObjects( void ) Return Value The number of Object reference(s) removed from the active ObjectGrid.
`RemoveMissingObjects`	Remove all reference to missing Object contained in the active ObjectGrid.
Declaration unsigned int RemoveMissingObjects( void ) Return Value To total amount of reference removed.
`RemoveEmptyCells`	Remove all the ObjectCell that does not contained any Object reference.
Declaration unsigned int RemoveEmptyCells( void ) Return Value To amount of ObjectCell removed from the ObjectGrid.
`Update`	Trigger a manual update of the ObjectGrid forcing to recalculate which ObjectCell are visible.
Declaration void Update( void )

ViewerMethod

The strategy to adopt while calculating which ObjectCell are visible from the associated viewer point of view for the active ObjectGrid.

kCartesian: Display all ObjectCell based on the grid occupancy of the viewer.
kPyramid: The ObjectCell visibility check is based on an approximated version of viewer frustum.
kTube: Cylindrical visibility check.
kGlobe: Spherical visibility check.