DHARTAPI.GraphGenerator.GraphGenerator Class Reference

Generate a graph of accessible space on a mesh. More...

Static Public Member Functions
static Graph	GenerateGraph (EmbreeBVH bvh, Vector3D start_point, Vector3D spacing, int max_nodes=-1, float up_step=0.2f, float up_slope=20, float down_step=0.2f, float down_slope=20, int max_step_connections=1, int min_connections=1, int core_count=-1, int[] obstacle_ids=null, int[] walkable_ids=null)
	Generate a graph of accessible space with the given settings. If no graph can be generated, null will be returned. More...

Detailed Description

Generate a graph of accessible space on a mesh.

Remarks

Use the graph generator to quickly map out accessible space in an environment for other analysis methods without needing to manually place nodes.

Member Function Documentation

GenerateGraph()

static Graph DHARTAPI.GraphGenerator.GraphGenerator.GenerateGraph ( EmbreeBVH  bvh, Vector3D  start_point, Vector3D  spacing, int  max_nodes = -1, float  up_step = 0.2f, float  up_slope = 20, float  down_step = 0.2f, float  down_slope = 20, int  max_step_connections = 1, int  min_connections = 1, int  core_count = -1, int[]  obstacle_ids = null, int[]  walkable_ids = null  )

static

Generate a graph of accessible space with the given settings. If no graph can be generated, null will be returned.

Parameters

bvh	A valid BVH to conduct the graph generation on. Geometry must be Z-Up.
start_point	The starting point for the graph generator. If this isn't above solid ground, no nodes will be generated.
spacing	Space between nodes. Lower values will yield more nodes for a higher resolution graph.
max_nodes	The maximum amount of nodes to generate.
up_step	Maximum height of a step the graph can traverse. Any steps higher this will be considered inaccessible.
up_slope	Maximum upward slope the graph can traverse in degrees. Any slopes steeper than this will be considered inaccessible.
down_step	Maximum step down the graph can traverse. Any steps steeper than this will be considered inaccessible.
down_slope	The maximum downward slope the graph can traverse. Any slopes steeper than this will be considered inaccessible.
max_step_connections	Multiplier for number of children to generate for each node. Increasing this value will increase the number of edges in the graph, and as a result the amount of memory the algorithm requires.
min_connections	The required out-degree for a node to be valid and stored. This must be greater than 0 and equal or less than the total connections created from max_step_connections. Default is 1. A value of 8 when max_step_connections=1 would be a grid.
core_count	Number of cores to use. -1 will use all available cores, and 0 will run a serialized version of the algorithm.
walkable_id	IDs of geometry to be considered as obstacles
obstacle_id	IDs of geometry to be considered as walkable surfaces

Returns

The resulting graph or, If no nodes were generated, null.

Note

All parameters relating to distances are in meters, and all angles are in degrees.

Geometry MUST be Z-UP in order for this to work.

MeshInfo Mesh = OBJLoader.LoadOBJ("plane.obj", CommonRotations.Yup_To_Zup);
EmbreeBVH BVH = new EmbreeBVH(Mesh);
 
Vector3D start_point = new Vector3D(0, 9000, 1);
Vector3D spacing = new Vector3D(1, 1, 1);
 
 // A standard graph with a spacing of 1 meter on each side with a maximum of 100 nodes
Graph G = DHARTAPI.GraphGenerator.GraphGenerator.GenerateGraph(BVH, start_point, spacing, 100);
 
 // A graph that cannot traverse stairs
Graph G = DHARTAPI.GraphGenerator.GraphGenerator.GenerateGraph(BVH, start_point, spacing, 100, up_step:0, downstep:0);
 
// A graph that is able to traverse up 30 degree slopes, but can only traverse down 10
// degree slopes
    Graph G = DHARTAPI.GraphGenerator.GraphGenerator.GenerateGraph(BVH, start_point, spacing, 100, up_slope:30, down_slope:10);

Referenced by StringToEdgeCost.Main().

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The documentation for this class was generated from the following file:

• src/Csharp/packages/graphgenerator/src/GraphGenerator.cs