頂点法線の可視化

ShowVerticesNormals.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

public class ShowVerticesNormals : MonoBehaviour
{

    MeshFilter meshFilter;
    Mesh mesh;
    Matrix4x4 matrix;

    Vector3[] normals;
    Vector3[] vertices;

    public bool draw = false;
    [Range(0.01f, 1.0f)]
    public float handleSize = 1;
    // Use this for initialization
    void Start()
    {
        meshFilter = new MeshFilter();
        mesh = new Mesh();
        matrix = new Matrix4x4();

        normals = new Vector3[0];
        vertices = new Vector3[0];
    }

    // Update is called once per frame
    void Update()
    {

    }

    void GetNormals()
    {
        meshFilter = GetComponent<MeshFilter>();
        mesh = meshFilter.mesh;
        normals = mesh.normals;
        vertices = mesh.vertices;
        matrix = meshFilter.transform.localToWorldMatrix;
    }

#if UNITY_EDITOR
    private void OnDrawGizmos()
    {
        if (!draw) return;
        if (normals == null || vertices == null) return;
        if (normals.Length != 0 && vertices.Length != 0) {

            for (int index = 0; index < normals.Length; index++) {
                Vector3 normal = normals[index];
                Vector3 vertex = vertices[index];
                Handles.color = new Color(normal.x, normal.y, normal.z);
                Handles.Slider(matrix.MultiplyPoint(vertices[index]), normals[index], handleSize, Handles.ArrowHandleCap, 1f);
            }

        }
    }

    [CustomEditor(typeof(ShowVerticesNormals))]
    public class ShowVerticesNormalsEditor : Editor
    {
        public override void OnInspectorGUI()
        {
            base.OnInspectorGUI();

            var showVerticesNormals = (ShowVerticesNormals)target;

            if(GUILayout.Button("GetNormals")) {
                showVerticesNormals.GetNormals();
            }
        }
    }

#endif
}