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API > API/Runtime > API/Runtime/Navmesh > API/Runtime/Navmesh/dtNavMeshQuery
Description
Finds the polygons along the navigation graph that touch the specified circle.
At least one result array must be provided.
The order of the result set is from least to highest cost to reach the polygon.
A common use case for this method is to perform Dijkstra searches. Candidate polygons are found by searching the graph beginning at the start polygon.
If a polygon is not found via the graph search, even if it intersects the search circle, it will not be included in the result set. For example:
polyA is the start polygon. polyB shares an edge with polyA. (Is adjacent.) polyC shares an edge with polyB, but not with polyA Even if the search circle overlaps polyC, it will not be included in the result set unless polyB is also in the set.
The value of the center point is used as the start position for cost calculations. It is not projected onto the surface of the mesh, so its y-value will effect the costs.
Intersection tests occur in 2D. All polygons and the search circle are projected onto the xz-plane. So the y-value of the center point does not effect intersection tests.
If the result arrays are to small to hold the entire result set, they will be filled to capacity.
| Name | findPolysAroundCircle |
| Type | function |
| Header File | /Engine/Source/Runtime/Navmesh/Public/Detour/DetourNavMeshQuery.h |
| Include Path | #include "Detour/DetourNavMeshQuery.h" |
| Source | /Engine/Source/Runtime/Navmesh/Private/Detour/DetourNavMeshQuery.cpp |
dtStatus findPolysAroundCircle
(
dtPolyRef startRef,
const dtReal * centerPos,
const dtReal radius,
const dtQueryFilter * filter,
dtPolyRef * resultRef,
dtPolyRef * resultParent,
dtReal * resultCost,
int * resultCount,
const int maxResult
) const
The status flags for the query.
Parameters
| Name | Remarks |
|---|---|
| startRef | The reference id of the polygon where the search starts. |
| centerPos | The center of the search circle. [(x, y, z)] |
| radius | The radius of the search circle. |
| filter | The polygon filter to apply to the query. |
| resultRef | The reference ids of the polygons touched by the circle. [opt] |
| resultParent | The reference ids of the parent polygons for each result. Zero if a result polygon has no parent. [opt] |
| resultCost | The search cost from centerPos to the polygon. [opt] |
| resultCount | The number of polygons found. |
| maxResult | The maximum number of polygons the result arrays can hold. |