Automatically Create Polygon Collider 2D From 2D Mesh in Unity

根据Mesh 来生成 Polygon Collider 2D：

在编辑器中编辑多边形碰撞器2D是不可能的，因为有数千个顶点。

想要支持具有多个非连接组件的网格？没问题

ColliderCreator C# Code

using System.Collections.Generic;
using UnityEngine;

public class ColliderCreator : MonoBehaviour
{
    void Start()
    {
        // Stop if no mesh filter exists or there's already a collider
        if (GetComponent<PolygonCollider2D>() || GetComponent<MeshFilter>() == null) {
            return;
        }

        // Get triangles and vertices from mesh
        int[] triangles = GetComponent<MeshFilter>().mesh.triangles;
        Vector3[] vertices = GetComponent<MeshFilter>().mesh.vertices;

        // Get just the outer edges from the mesh's triangles (ignore or remove any shared edges)
        Dictionary<string, KeyValuePair<int, int>> edges = new Dictionary<string, KeyValuePair<int, int>>();
        for (int i = 0; i < triangles.Length; i += 3) {
            for (int e = 0; e < 3; e++) {
                int vert1 = triangles[i + e];
                int vert2 = triangles[i + e + 1 > i + 2 ? i : i + e + 1];
                string edge = Mathf.Min(vert1, vert2) + ":" + Mathf.Max(vert1, vert2);
                if (edges.ContainsKey(edge)) {
                    edges.Remove(edge);
                } else {
                    edges.Add(edge, new KeyValuePair<int, int>(vert1, vert2));
                }
            }
        }

        // Create edge lookup (Key is first vertex, Value is second vertex, of each edge)
        Dictionary<int, int> lookup = new Dictionary<int, int>();
        foreach (KeyValuePair<int, int> edge in edges.Values) {
            if (lookup.ContainsKey(edge.Key) == false) {
                lookup.Add(edge.Key, edge.Value);
            }
        }

        // Create empty polygon collider
        PolygonCollider2D polygonCollider = gameObject.AddComponent<PolygonCollider2D>();
        polygonCollider.pathCount = 0;

        // Loop through edge vertices in order
        int startVert = 0;
        int nextVert = startVert;
        int highestVert = startVert;
        List<Vector2> colliderPath = new List<Vector2>();
        while (true) {

            // Add vertex to collider path
            colliderPath.Add(vertices[nextVert]);

            // Get next vertex
            nextVert = lookup[nextVert];

            // Store highest vertex (to know what shape to move to next)
            if (nextVert > highestVert) {
                highestVert = nextVert;
            }

            // Shape complete
            if (nextVert == startVert) {

                // Add path to polygon collider
                polygonCollider.pathCount++;
                polygonCollider.SetPath(polygonCollider.pathCount - 1, colliderPath.ToArray());
                colliderPath.Clear();

                // Go to next shape if one exists
                if (lookup.ContainsKey(highestVert + 1)) {

                    // Set starting and next vertices
                    startVert = highestVert + 1;
                    nextVert = startVert;

                    // Continue to next loop
                    continue;
                }

                // No more verts
                break;
            }
        }
    }
}

using System.Collections.Generic;

using UnityEngine;

public class ColliderCreator : MonoBehaviour

{

void Start()

{

// Stop if no mesh filter exists or there's already a collider

if (GetComponent<PolygonCollider2D>() || GetComponent<MeshFilter>() == null) {

return;

}

// Get triangles and vertices from mesh

int[] triangles = GetComponent<MeshFilter>().mesh.triangles;

Vector3[] vertices = GetComponent<MeshFilter>().mesh.vertices;

// Get just the outer edges from the mesh's triangles (ignore or remove any shared edges)

Dictionary<string, KeyValuePair<int, int>> edges = new Dictionary<string, KeyValuePair<int, int>>();

for (int i = 0; i < triangles.Length; i += 3) {

for (int e = 0; e < 3; e++) {

int vert1 = triangles[i + e];

int vert2 = triangles[i + e + 1 > i + 2 ? i : i + e + 1];

string edge = Mathf.Min(vert1, vert2) + ":" + Mathf.Max(vert1, vert2);

if (edges.ContainsKey(edge)) {

edges.Remove(edge);

} else {

edges.Add(edge, new KeyValuePair<int, int>(vert1, vert2));

}

// Create edge lookup (Key is first vertex, Value is second vertex, of each edge)

Dictionary<int, int> lookup = new Dictionary<int, int>();

foreach (KeyValuePair<int, int> edge in edges.Values) {

if (lookup.ContainsKey(edge.Key) == false) {

lookup.Add(edge.Key, edge.Value);

}

// Create empty polygon collider

PolygonCollider2D polygonCollider = gameObject.AddComponent<PolygonCollider2D>();

polygonCollider.pathCount = 0;

// Loop through edge vertices in order

int startVert = 0;

int nextVert = startVert;

int highestVert = startVert;

List<Vector2> colliderPath = new List<Vector2>();

while (true) {

// Add vertex to collider path

colliderPath.Add(vertices[nextVert]);

// Get next vertex

nextVert = lookup[nextVert];

// Store highest vertex (to know what shape to move to next)

if (nextVert > highestVert) {

highestVert = nextVert;

}

// Shape complete

if (nextVert == startVert) {

// Add path to polygon collider

polygonCollider.pathCount++;

polygonCollider.SetPath(polygonCollider.pathCount - 1, colliderPath.ToArray());

colliderPath.Clear();

// Go to next shape if one exists

if (lookup.ContainsKey(highestVert + 1)) {

// Set starting and next vertices

startVert = highestVert + 1;

nextVert = startVert;

// Continue to next loop

continue;

}

// No more verts

break;

}

原文地址：https://www.h3xed.com/programming/automatically-create-polygon-collider-2d-from-2d-mesh-in-unity