How to fill polygon collider with a solid color?

Questions & Answers
1

Is there any way to fill a polygon collider with a solid color, using a sprite renderer or similar? Both ingame and ineditor.

It would be nice if there is some efficient way of doing this. And even better if there was anti aliased filling.

3

I figured it out.
This is what I did:

[RequireComponent(typeof(PolygonCollider2D))]
[RequireComponent(typeof(MeshFilter))]
[RequireComponent(typeof(MeshRenderer))]
[ExecuteInEditMode]
public class ColliderToMesh : MonoBehaviour {
	PolygonCollider2D pc2 ;
	void Start () {
		pc2 = gameObject.GetComponent<PolygonCollider2D>();

		//Render thing
		int pointCount = 0;
		pointCount = pc2.GetTotalPointCount();
		MeshFilter mf = GetComponent<MeshFilter>();
		Mesh mesh = new Mesh();

		Vector2[] points = pc2.points;
		Vector3[] vertices = new Vector3[pointCount];
		Vector2[] uv = new Vector2[pointCount];

		for(int j=0; j<pointCount; j++){
			Vector2 actual = points[j];
			vertices[j] = new Vector3(actual.x, actual.y, 0);
			uv[j] = actual;
		}

		Triangulator tr = new Triangulator(points);
		int [] triangles = tr.Triangulate();

		mesh.vertices = vertices;
		mesh.triangles = triangles;
		mesh.uv = uv;

		mf.mesh = mesh;
		//Render thing
	}
}

The Triangulator class is in this link:
http://wiki.unity3d.com/index.php?title=Triangulator

Or you can put it all in the update and see it changing as you edit the collider.

#if UNITY_EDITOR
void Update(){
	if (Application.isPlaying)
		return;
	if(pc2 != null){
		//AllTheRenderThingFromTheStart ();
	}
}
#endif
4

The Answer above help tremendously. Here is my addition, which adds an optional outline with a LineRenderer.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

[RequireComponent(typeof(PolygonCollider2D))]
[RequireComponent(typeof(MeshFilter))]
[RequireComponent(typeof(MeshRenderer))]
[RequireComponent(typeof(LineRenderer))]

public class MeshFromPolygonCollider2D : MonoBehaviour
{
    // Based onh ttp://answers.unity3d.com/questions/835675/how-to-fill-polygon-collider-with-a-solid-color.html

    public enum Interior {  None, Filled } 
    public enum Outline {  None, Open, Closed }

    public Interior interior = Interior.Filled;
    public Outline outline = Outline.Closed;

    public PolygonCollider2D polygonCollider2D;
    public MeshFilter meshFilter;
    public MeshRenderer meshRenderer;
    public LineRenderer lineRenderer;
    public bool isWorldSpaceUV;
    public bool isOutlineClosed = true;

    private void Start()
    {
        Init();
    }
    public void Init()
    {
        CreateMesh();
        CreateLine();
    }

    void CreateMesh() { 
        if (polygonCollider2D == null) polygonCollider2D = gameObject.GetComponent<PolygonCollider2D>();
        if (meshFilter == null) meshFilter = GetComponent<MeshFilter>();
        if (meshRenderer == null) meshRenderer = GetComponent<MeshRenderer>();
        if ((meshFilter == null || meshRenderer == null) && interior == Interior.None) return;
        if (meshFilter == null)
        {
            Debug.LogError(this + " has null meshFilter");
            return;
        }
        if (meshRenderer == null)
        {
            Debug.LogError(this + " has null meshRenderer");
            return;
        }

        if (interior == Interior.None)
        {
            meshRenderer.enabled = false;
            return;
        } else
        {
            meshRenderer.enabled = true;
        }
        

        //Render thing
        int pointCount = 0;
        pointCount = polygonCollider2D.GetTotalPointCount();
        Mesh mesh = new Mesh();
        Vector2[] points = polygonCollider2D.points;
        Vector3[] vertices = new Vector3[pointCount];
        Vector2[] uv = new Vector2[pointCount];
        for (int j = 0; j < pointCount; j++)
        {
            Vector2 actual = points[j];
            vertices[j] = new Vector3(actual.x, actual.y, 0);
            if (isWorldSpaceUV)
            {
                uv[j] = actual;

            }
            else
            {
                uv[j] = new Vector2(actual.x / polygonCollider2D.bounds.size.x, actual.y / polygonCollider2D.bounds.size.y);
            }
        }
        Triangulator tr = new Triangulator(points);
        int[] triangles = tr.Triangulate();
        mesh.vertices = vertices;
        mesh.uv = uv;
        mesh.triangles = triangles;
        meshFilter.mesh = mesh;
    }

     void CreateLine()
    {
        if (polygonCollider2D == null) polygonCollider2D = gameObject.GetComponent<PolygonCollider2D>();
        if (lineRenderer == null) lineRenderer = GetComponent<LineRenderer>();

        if (lineRenderer == null && outline == Outline.None) return;
        if (lineRenderer == null)
        {
            Debug.LogError(this + " has null lineRenderer");
            return;
        }
        if (outline == Outline.None)
        {
            lineRenderer.enabled = false;
            return;
        } else
        {
            lineRenderer.enabled = true;
        }

        //Render thing
        int pointCount = 0;
        pointCount = polygonCollider2D.GetTotalPointCount();
        if (pointCount < 1) return;

        if (outline == Outline.Closed) pointCount++;
        Vector2[] points = polygonCollider2D.points;

        lineRenderer.numPositions = pointCount;

        for (int j = 0; j < polygonCollider2D.GetTotalPointCount(); j++)
        {
            Vector2 actual = points[j];
            lineRenderer.SetPosition(j, new Vector3(actual.x, actual.y, 0));
        }

        if (outline == Outline.Closed)
        {
            Vector2 actual = points[0];
            lineRenderer.SetPosition(pointCount-1, new Vector3(actual.x, actual.y, 0));
        }
    }


}

and then if you want it to automatically redraw when using the edit collider button in the Editor

using UnityEngine;
using System.Collections;
using UnityEditor;

[CustomEditor(typeof(MeshFromPolygonCollider2D))]
public class MeshFromPolygonCollider2DEditor : Editor
{
    public  void OnSceneGUI()
    {
        // enable update when editing mesh collider in Editor
        MeshFromPolygonCollider2D myTarget = (MeshFromPolygonCollider2D)target;
        myTarget.Init();
    }
}
2

A friend of mine solved this by using a Polygon Collider 2D with a Mesh Renderer, Mesh Filter, a custom sprite shader and a script that creates a mesh for the Polygon Collider 2D. The solution is more complicated than what can be described here, but I’ll try to make a blog entry about it later.