Mesh Bender

using BezierCurveZ;
using System.Collections;
using System.Collections.Generic;
using Unity.VisualScripting;
using UnityEditor;
using UnityEngine;
using Utility;

[ExecuteAlways]
[SelectionBase]
public class MeshBender : MonoBehaviour
{
    public Mesh originalMesh;
    public float originalLength = 1f;
    public MeshFilter meshFilter;
    [Tooltip("Only first segment will be accounted")]
    [ContextMenuItem("UpdateMesh", "UpdateMesh")]
    public Curve curve;
    private void OnEnable()
    {
        if (originalMesh.IsNullOrDestroyed() && meshFilter) originalMesh = meshFilter.sharedMesh;
        UpdateMesh();
    }

    [ContextMenu("UpdateMesh")]
    public void UpdateMesh()
    {
        var mesh = meshFilter.sharedMesh;
        if (mesh == originalMesh)
            mesh = originalMesh.Copy();

        Transform mfTransform = meshFilter.transform;
        var thisToMeshMatrix = mfTransform.worldToLocalMatrix * transform.localToWorldMatrix;
        var meshToThisMatrix = transform.worldToLocalMatrix * mfTransform.localToWorldMatrix;

        var verts = originalMesh.vertices;
        for (int i = 0; i < verts.Length; i++)
        {
            var v = meshToThisMatrix.MultiplyPoint3x4(verts[i]);
            var t = Mathf.Clamp01(v.z / originalLength);
            var point = curve.VertexData.GetPointFromTime(t);
            var vRelToPoint = v - new Vector3(0, 0, t * originalLength);
            verts[i] = thisToMeshMatrix.MultiplyPoint3x4(point.Position + point.Rotation * vRelToPoint);
        }
        mesh.vertices = verts;
        meshFilter.sharedMesh = mesh;
    }
#if UNITY_EDITOR
    private void OnDrawGizmosSelected()
    {
        var m = Handles.matrix;
        var c = Handles.color;
        Handles.color = new Color(.3f, .3f, 1f);
        Handles.matrix = transform.localToWorldMatrix;

        var origTgt = Vector3.forward * originalLength;
        Handles.DrawAAPolyLine(Vector3.zero, origTgt);
        Handles.DrawAAPolyLine(Vector3.right * -.5f, Vector3.right * .5f);
        Handles.DrawAAPolyLine(Vector3.forward * originalLength + Vector3.right * -.5f, Vector3.forward * originalLength + Vector3.right * .5f);

        Handles.color = new Color(.3f, 1f, .3f);
        var tgt = curve.Points[curve.GetPointIndex(1)];
        Handles.DrawAAPolyLine(Vector3.right * -.5f, Vector3.right * .5f);
        Handles.DrawAAPolyLine(tgt + tgt.right * -.5f, tgt + tgt.right * .5f);
        Handles.DrawAAPolyLine(curve.VertexDataPoints);

        Handles.color = c;
        Handles.matrix = m;
    }
#endif
}