Mesh.GetAllBoneWeights

Returns

NativeArray<BoneWeight1> Returns all non-zero bone weights for the Mesh, in vertex index order.

Description

Gets the bone weights for the Mesh.

Use Mesh.GetBonesPerVertex to get the number of non-zero weights for each vertex, and then use that to iterate over this data.

For each vertex, the BoneWeight1 structs are sorted by BoneWeight1.weight, in descending order.

Additional resources: Mesh.SetBoneWeights, Mesh.GetBonesPerVertex, Mesh.boneWeights, Mesh.GetBoneWeights ModelImporter.maxBonesPerVertex, QualitySettings.skinWeights, SkinnedMeshRenderer.quality.

using UnityEngine;

public class TestSkinnedMesh : MonoBehaviour {
    void Start()
    {
        // Get a reference to the mesh
        var skinnedMeshRenderer = GetComponent<SkinnedMeshRenderer>();
        var mesh = skinnedMeshRenderer.sharedMesh;

        // Get the number of bone weights per vertex
        var bonesPerVertex = mesh.GetBonesPerVertex();
        if (bonesPerVertex.Length == 0)
        {
             return;
        }

        // Get all the bone weights, in vertex index order
        var boneWeights = mesh.GetAllBoneWeights();

        // Keep track of where we are in the array of BoneWeights, as we iterate over the vertices
        var boneWeightIndex = 0;

        // Iterate over the vertices
        for (var vertIndex = 0; vertIndex < mesh.vertexCount; vertIndex++)
        {
            var totalWeight = 0f;
            var numberOfBonesForThisVertex = bonesPerVertex[vertIndex];
            Debug.Log("This vertex has " + numberOfBonesForThisVertex + " bone influences");

            // For each vertex, iterate over its BoneWeights
            for (var i = 0; i < numberOfBonesForThisVertex; i++)
            {
                var currentBoneWeight = boneWeights[boneWeightIndex];
                totalWeight += currentBoneWeight.weight;
                if (i > 0)
                {
                    Debug.Assert(boneWeights[boneWeightIndex - 1].weight >= currentBoneWeight.weight);
                }
                boneWeightIndex++;
            }
            Debug.Assert(Mathf.Approximately(1f, totalWeight));
        }
    }
}