FMath::SegmentDistToSegment
#include "Math/UnrealMathUtility.h"
Access: public
Specifiers: static
Description
Finds the closest pair of points between two 3D line segments. Returns the points on each segment that are nearest to each other, not a distance value.
Caveats & Gotchas
- • If either segment has zero length (start == end), the function has undefined behaviour — use SegmentDistToSegmentSafe instead when segment length cannot be guaranteed.
- • The distance between OutP1 and OutP2 equals the minimum distance between the two segments; compute it yourself with FVector::Dist(OutP1, OutP2) if you need the scalar value.
- • Segments are passed by value (not reference), so large vectors are copied on each call — negligible for FVector but worth noting in tight loops.
Signature
static CORE_API void SegmentDistToSegment(FVector A1, FVector B1, FVector A2, FVector B2, FVector& OutP1, FVector& OutP2)Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| A1 | FVector | Start of the first segment. | — |
| B1 | FVector | End of the first segment. | — |
| A2 | FVector | Start of the second segment. | — |
| B2 | FVector | End of the second segment. | — |
| OutP1 | FVector& | Closest point on segment 1 to segment 2. | — |
| OutP2 | FVector& | Closest point on segment 2 to segment 1. | — |
Return Type
void Example
Find the gap between two ropes and apply a force C++
FVector P1, P2;
FMath::SegmentDistToSegment(RopeA_Start, RopeA_End, RopeB_Start, RopeB_End, P1, P2);
float Gap = FVector::Dist(P1, P2);
if (Gap < AttractRadius)
{
// P1 and P2 are the closest contact points
ApplyAttractForce(P1, P2, Gap);
}Tags
Version History
Introduced in: 4.0
| Version | Status | Notes |
|---|---|---|
| 5.6 | stable | — |
Feedback
Was this helpful?