Mesh.MeshData.GetIndexData

Returns

NativeArray<T> Returns a NativeArray containing the index buffer data.

Description

Gets raw data from the index buffer of the MeshData.

GetIndexData returns a direct "pointer" into the raw index buffer data without any memory allocations, data copies or conversions. You do not need to dispose of the returned NativeArray, because it does not represent a new memory allocation.

You need to know the exact Mesh data layout work with this data, including the presence and formats of all vertex attributes. The data layout matches the one from Mesh.SetIndexBufferData. Typically, Meshes with a 16 bit index format use the ushort data type, and Meshes with a 32 bit index format use the int data type.

If the MeshData is writeable, and you have set the index buffer size and format using Mesh.MeshData.SetIndexBufferParams, you can write indices directly to the array. If the MeshData is read-only, the array is read-only.

Additional resources: Mesh.AllocateWritableMeshData, Mesh.AcquireReadOnlyMeshData, Mesh.MeshData.SetIndexBufferParams.

using UnityEngine;
using UnityEngine.Rendering;
public class ExampleScript : MonoBehaviour
{
    void Start()
    {
        var mesh = new Mesh();
        mesh.vertices = new[] {Vector3.one, Vector3.zero, Vector3.up};
        mesh.indexFormat = IndexFormat.UInt16;
        mesh.triangles = new[] {2, 0, 1};
        using (var data = Mesh.AcquireReadOnlyMeshData(mesh))
        {
            var indices = data[0].GetIndexData<ushort>();
            // prints 2, 0, 1
            foreach (var i in indices)
                Debug.Log(i);
        }
    }
}

Additional resources: Mesh.SetIndexBufferParams, Mesh.SetIndexBufferData, GetVertexData, Mesh.AcquireReadOnlyMeshData.