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Vector3 Multilerp (multiple lerps) for handline waypoints.
using System;
using UnityEngine;
namespace NG
{
public static class Vector3Ext
{
#region Multilerp
// This is not very optimized. There are at least n + 1 and at most 2n Vector3.Distance
// calls (where n is the number of waypoints).
public static Vector3 MultiLerp(Vector3[] waypoints, float ratio)
{
Vector3 position = Vector3.zero;
float totalDistance = waypoints.MultiDistance();
float distanceTravelled = totalDistance * ratio;
int indexLow = GetVectorIndexFromDistanceTravelled(waypoints, distanceTravelled);
int indexHigh = indexLow + 1;
// we're done
if (indexHigh > waypoints.Length - 1)
return waypoints[waypoints.Length - 1];
// calculate the distance along this waypoint to the next
Vector3[] completedWaypoints = new Vector3[indexLow + 1];
for (int i = 0; i < indexLow + 1; i++)
{
completedWaypoints[i] = waypoints[i];
}
float distanceCoveredByPreviousWaypoints = completedWaypoints.MultiDistance();
float distanceTravelledThisSegment = distanceTravelled - distanceCoveredByPreviousWaypoints;
float distanceThisSegment = Vector3.Distance(waypoints[indexLow], waypoints[indexHigh]);
float currentRatio = distanceTravelledThisSegment / distanceThisSegment;
position = Vector3.Lerp(waypoints[indexLow], waypoints[indexHigh], currentRatio);
return position;
}
public static float MultiDistance(this Vector3[] waypoints)
{
float distance = 0f;
for (int i = 0; i < waypoints.Length; i++)
{
if (i + 1 > waypoints.Length - 1)
break;
distance += Vector3.Distance(waypoints[i], waypoints[i + 1]);
}
return distance;
}
public static int GetVectorIndexFromDistanceTravelled(Vector3[] waypoints, float distanceTravelled)
{
float distance = 0f;
for (int i = 0; i < waypoints.Length; i++)
{
if (i + 1 > waypoints.Length - 1)
return waypoints.Length - 1;
float segmentDistance = Vector3.Distance(waypoints[i], waypoints[i + 1]);
if (segmentDistance + distance > distanceTravelled)
{
return i;
}
distance += segmentDistance;
}
return waypoints.Length - 1;
}
#endregion
}
}
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