how to code a skinnedMesh ?

Questions & Answers
1

enter code hereHi everyone, i’m having problems coding bindposes for a simple skinnedMeshRenderer. I’m trying to create a rigidBody GameObject for each of my vertex and binding it to the vertex as a bone. this system is quite simple but no matter how i am coding this my mesh ends up totally messed up and the console is logging “Bones do not match BindPose”. I really dont know what i am doing wrong and i came to simplify my code so far that it looks more like a Learning exemple but even now it doesn’t work !!

Could someone please help me with that ?

//this mesh is assigned in the editor, right now i'm using a simple quad
    public Mesh mesh;

	void Start () {

        //i will store the bones in this array
        Transform[] bones = new Transform[4];

        //the bindposes will come in this one, it has the same size as the bones one
        Matrix4x4[] bindPoses = new Matrix4x4[4];

        //one boneWeight foreach vertex
        BoneWeight[] boneWeights = new BoneWeight[4];

        for(int i = 0; i < mesh.vertexCount; i++)
        {

            bones *= new GameObject("bone").transform;*

bones_.position = transform.TransformPoint(mesh.vertices*);*_

bindPoses = bones_.worldToLocalMatrix * transform.localToWorldMatrix;_

boneWeights*.boneIndex0 = i;*
boneWeights*.weight0 = 1;*
}

mesh.bindposes = bindPoses;
mesh.boneWeights = boneWeights;

gameObject.AddComponent().sharedMesh = mesh;
GetComponent().bones = bones;

* }*

2

The code looks right and works with a few changes, even though I’m answering this too late.

I’ve just changed it a bit for future references, placing a few things to avoid messing up with the wrong mesh. Just attach the following script to a GO and select any mesh. Note that this way we will get a bone for every vertex in the mesh, so have in mind that the script is intended for learning purposes only.

using UnityEngine;

[RequireComponent(typeof(SkinnedMeshRenderer))]
public class Mine : MonoBehaviour
{
    void Start()
    {
        SkinnedMeshRenderer skinned = this.GetComponent<SkinnedMeshRenderer>();

        if (skinned.sharedMesh == null || skinned.sharedMesh.vertexCount == 0)
            return;

        Mesh mesh = (Mesh)Object.Instantiate(skinned.sharedMesh);
        mesh.RecalculateBounds();
        mesh.RecalculateNormals();
        mesh.RecalculateTangents();
        Transform[] bones = new Transform[mesh.vertexCount];
        Matrix4x4[] bindPoses = new Matrix4x4[mesh.vertexCount];
        BoneWeight[] boneWeights = new BoneWeight[mesh.vertexCount];

        for (int index = 0; index < mesh.vertexCount; index++)
        {
            bones[index] = new GameObject(string.Format("Bone [{0}]", index)).transform;
            bones[index].SetParent(this.transform);
            bones[index].position = this.transform.TransformPoint(mesh.vertices[index]);
            bindPoses[index] = bones[index].worldToLocalMatrix * this.transform.localToWorldMatrix;
            boneWeights[index].boneIndex0 = index;
            boneWeights[index].weight0 = 1;
        }
        
        mesh.bindposes = bindPoses;
        mesh.boneWeights = boneWeights;
        skinned.sharedMesh = mesh; 
        skinned.bones = bones;
    }
}

The above code was tested in Unity 5.6.

-Rod

3

The question is a bit old but i probably had the same problem recently. After setting the boneWeights of the mesh you need to set the vertices again.

example:

Vector3[] vertices = mesh.vertices;
BoneWeight[] weights = new BoneWeight[mesh.vertices.length];
// Some code...
mesh.boneWeights = weights; // after this the mesh is "messed up"
mesh.vertices = vertices; // this will reset the vertices

Hopefully this solves the problem for you aswell. Good Luck!

4

Hi!,
Theres an way to keep changes on mesh after unity reset? My mesh back to original form…