Mesh.GetVertexAttributeStream

Parameters

Returns

int Stream index of the data attribute, or -1 if it is not present.

Description

Gets the vertex buffer stream index of a specific vertex data attribute on this Mesh.

Meshes usually use a single vertex buffer stream, but it is possible to set up a vertex layout where attributes use different vertex buffers (see SetVertexBufferParams). When you use such a layout, use this function to query which vertex buffer stream a given attribute is part of.

Note that this function returns the index of the stream, without specifying where the attribute is within the stream. To identify the location of a given attribute in the stream, use GetVertexAttributeOffset.

using UnityEngine;
using UnityEngine.Rendering;

public class ExampleScript : MonoBehaviour
{
    void Start()
    {
        // Create a Mesh with custom vertex data layout:
        // position and normal go into stream 0,
        // color goes into stream 1.
        var mesh = new Mesh();
        mesh.SetVertexBufferParams(10,
            new VertexAttributeDescriptor(VertexAttribute.Position, VertexAttributeFormat.Float32, 3, stream:0),
            new VertexAttributeDescriptor(VertexAttribute.Normal, VertexAttributeFormat.Float32, 3, stream:0),
            new VertexAttributeDescriptor(VertexAttribute.Color, VertexAttributeFormat.UNorm8, 4, stream:1));

        // Prints stream indices: 0, 0, 1
        Debug.Log($"Position stream {mesh.GetVertexAttributeStream(VertexAttribute.Position)}");
        Debug.Log($"Normal stream {mesh.GetVertexAttributeStream(VertexAttribute.Normal)}");
        Debug.Log($"Color stream {mesh.GetVertexAttributeStream(VertexAttribute.Color)}");

        // Cleanup
        Object.DestroyImmediate(mesh);
    }
}

Additional resources: VertexAttribute, HasVertexAttribute, GetVertexAttributeOffset, vertexBufferCount, GetVertexBufferStride.