VectorGraphicsで曲線を描画するデモ

Spline.cs

using System.Collections;
using System.Collections.Generic;
using Unity.VectorGraphics;
using UnityEngine;

[RequireComponent(typeof(MeshRenderer))]
[RequireComponent(typeof(MeshFilter))]
[DisallowMultipleComponent]
public class Spline : MonoBehaviour
{
    [SerializeField] [Range(0.01f, 0.5f)] float thick;
    [SerializeField] Color color;

    [SerializeField] Transform[] controlPoints;

    private Scene scene;
    private Path path;
    private VectorUtils.TessellationOptions options;
    private Mesh mesh;

    void Awake()
    {
       
        scene = new Scene();

        path = new Path()
        {
            // パスの設定
            Contour = new BezierContour() {
                Segments = new BezierPathSegment[3],    // 頂点数は3つ
                Closed = false                          // パスを閉じない
            },
            // 線のパラメーター
            PathProps = new PathProperties()
            {
                Stroke = new Stroke() {
                    Color = Color.white,    // 色
                    HalfThickness = thick   // 線の太さ
                }
            }
        };

        // メッシュに形状を登録
        // 単一パスなのでルートに登録するだけ
        var node = new SceneNode()
        {
            Drawables = new List<IDrawable> { path }
        };
        scene.Root = node;

        

        // 生成するメッシュの設定
        options = new VectorUtils.TessellationOptions() {
            StepDistance = 100,
            MaxCordDeviation = 0.05f,
            MaxTanAngleDeviation = 0.05f,
            SamplingStepSize = 0.01f
        };

        mesh = new Mesh();
        GetComponent<MeshFilter>().mesh = mesh;
    }

    private void OnDestroy()
    {
        Destroy(mesh);
    }

    private void Update()
    {
        bool isChanged = false;

        // ---------------------- セグメント 1 ------------------------
        if (controlPoints[0].hasChanged)
        {
            path.Contour.Segments[0].P0 = controlPoints[0].localPosition;
            controlPoints[0].hasChanged = false;
            isChanged = true;
        }
        if (controlPoints[1].hasChanged)
        {
            path.Contour.Segments[0].P1 = controlPoints[1].localPosition;
            controlPoints[1].hasChanged = false;
            isChanged = true;
        }


        // ---------------------- セグメント 2 ------------------------
        if (controlPoints[2].hasChanged)
        {
            path.Contour.Segments[0].P2 = controlPoints[2].localPosition;
            controlPoints[2].hasChanged = false;
            isChanged = true;
        }
        if (controlPoints[3].hasChanged)
        {
            path.Contour.Segments[1].P0 = controlPoints[3].localPosition;
            controlPoints[3].hasChanged = false;
            isChanged = true;
        }
        if (controlPoints[4].hasChanged)
        {
            path.Contour.Segments[1].P1 = controlPoints[4].localPosition;
            controlPoints[4].hasChanged = false;
            isChanged = true;
        }

        // ---------------------- セグメント 3 ------------------------
        if (controlPoints[5].hasChanged)
        {
            path.Contour.Segments[1].P2 = controlPoints[5].localPosition;
            controlPoints[5].hasChanged = false;
            isChanged = true;
        }
        if (controlPoints[6].hasChanged)
        {
            path.Contour.Segments[2].P0 = controlPoints[6].localPosition;
            controlPoints[6].hasChanged = false;
            isChanged = true;
        }

        if (isChanged)
        {
            UpdateMesh();
        }
    }


    void UpdateMesh()
    {
        var geoms = VectorUtils.TessellateScene(scene, options);    // ジオメトリを生成
        VectorUtils.FillMesh(mesh, geoms, 1.0f);                    // メッシュに焼き付け
        Debug.Log("tranform update");
    }

    private void OnDrawGizmos()
    {
        Gizmos.DrawLine(controlPoints[0].localPosition, controlPoints[1].localPosition);
        Gizmos.DrawLine(controlPoints[2].localPosition, controlPoints[3].localPosition);
        Gizmos.DrawLine(controlPoints[3].localPosition, controlPoints[4].localPosition);
        Gizmos.DrawLine(controlPoints[5].localPosition, controlPoints[6].localPosition);
    }
}

http://tsubakit1.hateblo.jp/entry/2018/05/22/233000