combine children, apply mesh collider to parent

Unity Engine
1

ok, I have a gameObject w/ a few different meshes as children

what I want to do is treat them as a single object so I use combine children

now I want to apply a mesh collider to the resulting parent mesh

cant figure out how to do this

the goal is to treat the parent object as a single mesh, particularly w/r/t raytracing, tracing mouseclicks etc

thanks in advance!

2

I am looking to do the same. Have you figured this out since you posted this 2 years ago??

3

Lo!

Im just tried the same, but its not work to me too.
I tried in this way:

function Start () 
	{

	gameObject.AddComponent(MeshFilter);
	gameObject.AddComponent(MeshRenderer);
	gameObject.AddComponent(Rigidbody);
	gameObject.AddComponent(MeshCollider);

	for (var child in transform)

	child.position += transform.position;
	transform.position = Vector3.zero;
	transform.rotation = Quaternion.identity;

	var meshFilters = GetComponentsInChildren(MeshFilter);
	var combine : CombineInstance[] = new CombineInstance[meshFilters.Length-1];
	var index = 0;


	for (var i = 0; i < meshFilters.Length; i++){
		if (meshFilters[i].sharedMesh == null) continue;
		combine[index].mesh = meshFilters[i].sharedMesh;
		combine[index++].transform = meshFilters[i].transform.localToWorldMatrix;
		meshFilters[i].renderer.enabled = false;
	}

	GetComponent(MeshFilter).mesh = new Mesh();
	GetComponent(MeshFilter).mesh.CombineMeshes (combine);

	GetComponent(MeshCollider).sharedMesh = GetComponent(MeshFilter).mesh;

	renderer.material = meshFilters[1].renderer.sharedMaterial;

}

This script is a mixed script, cut from several scripts, and I really cant figure out, how to make it work well.

Somebody help me, pls.

4

Where exactly is your script failing? Is it failing when it assigns the MeshCollider.sharedMesh, or when combining meshes in the first place?

5

The combining done succesfully, and it looks like the collider is fine too, at runtime it got an instance as mesh, but there is no effect: the combined mesh simply falls down through the obstacles.

I tried out a modified version(without the combining function)of this collider preparer script in a simple object. Works fine. So, as I see, somehow the combined object’s mesh not good for a collider, or I put the mesh data for the collider in a bad way.

6

Is it possible to combine meshes and make them static meshes with colliders generated as well?

7

so, any ideas? I think this is an interesting question :slight_smile:

8

If this is for a STATIC mesh, did you check that the “gravity” checkbox on rigidbody is unchecked?

Also there is limit of vertexes for collision MESH, for what I know.

9

has anyone found a solution to this? I(obviously) lose my colliders when I combine too, but still cant get the new colliders to work yet. Any solutions are welcome

10

See my comments at the end of this thread.
http://forum.unity3d.com/threads/71391-MeshCollider-is-not-getting-updated-when-adding-vertex-to-mesh

  1. Use CombineMeshes

  2. Example code from ScriptRef Dont do this, just leave it out
    transform.GetComponent().mesh = new Mesh();

3.MeshCollider.sharedMesh=null;
MeshCollider.sharedMesh=theNewMesh;

The mesh collider will now work and memory will not increase.

11

@Tzan Thanks You So Much Bro It Works. I just added These Two Lines After The Final Mesh Line!

  1. GetComponent ().sharedMesh = null;
  2. GetComponent< MeshCollider> () .sharedMesh= finalMesh;
12

So here is the complete Mesh Combine Script With Collider Also. You can use this script on any mesh . Thanks Me Later.:

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

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

public class MeshCombine : MonoBehaviour
{
// Start is called before the first frame update
void Start()
{
Quaternion OldRot = transform.rotation;
Vector3 OldPos = transform.position;

transform.rotation = Quaternion.identity;
transform.position = Vector3.zero;

MeshFilter[ ] filters = GetComponentsInChildren();

Debug.Log(name + “is combining” + filters.Length + “meshes!”);

Mesh finalMesh = new Mesh ();
GetComponent ().sharedMesh = null;
GetComponent< MeshCollider> () .sharedMesh= finalMesh;

CombineInstance[ ] combiners = new CombineInstance[filters.Length];

for(int a = 0 ; a <filters.Length ; a++)
{
if(filters[a].transform == transform)
continue;

combiners[a].subMeshIndex = 0;
combiners[a].mesh = filters [a].sharedMesh;
combiners[a].transform = filters[a].transform.localToWorldMatrix;
}

finalMesh.CombineMeshes (combiners);

GetComponent ().sharedMesh = finalMesh;

transform.rotation = OldRot;
transform.position = OldPos;

for(int a = 0; a < transform.childCount; a++)

transform.GetChild(a).gameObject.SetActive(false);

}

}

13

I’m glad old me from 2011 was able to help a bit :slight_smile:

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