# SetVertexBufferData

> Sets the data within a specific vertex buffer stream, copying elements from a source container to a destination range within the Mesh 's buffer.

## Definition

* **Type:** Method
* **Namespace:** [UnityEngine](/engine/6000.3/script-reference/unityengine.md)
* **Assembly:** UnityEngine.CoreModule

## SetVertexBufferData\<T>(NativeArray\<T>, int, int, int, int, MeshUpdateFlags)

Sets the data within a specific vertex buffer stream, copying elements from a source container to a destination range within the `Mesh`'s buffer.

```csharp
public void SetVertexBufferData<T>(NativeArray<T> data, int dataStart, int meshBufferStart, int count, int stream = 0, MeshUpdateFlags flags = MeshUpdateFlags.Default) where T : struct
```

### Parameters

**** (\[NativeArray\<T>]\(/engine/6000.3/script-reference/unity/collections/nativearray1)): The source container from which vertex data is copied.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The first element in the data to copy from.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The first element in mesh vertex buffer to receive the data.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The number of elements of type `T` to copy from the `data` container into the [Mesh](/engine/6000.3/script-reference/unityengine/mesh.md) buffer.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): Vertex buffer stream to set data for (default 0). Value must be within range 0 to 3.**** (\[MeshUpdateFlags]\(/engine/6000.3/script-reference/unityengine/rendering/meshupdateflags)): Flags controlling the function behavior, see [MeshUpdateFlags](/engine/6000.3/script-reference/unityengine/rendering/meshupdateflags.md).

### Remarks

Simple usage of [Mesh](/engine/6000.3/script-reference/unityengine/mesh.md) scripting API involves using functions like [Mesh.vertices](/engine/6000.3/script-reference/unityengine/mesh/vertices.md), [Mesh.normals](/engine/6000.3/script-reference/unityengine/mesh/normals.md) to setup vertex data.

For advanced use cases that require maximum performance, you can use the advanced API, which has functions like [Mesh.SetSubMesh](/engine/6000.3/script-reference/unityengine/mesh/setsubmesh.md), [Mesh.SetIndexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferparams.md), [Mesh.SetIndexBufferData](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferdata.md), and [Mesh.SetVertexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setvertexbufferparams.md). This advanced API gives access to the underlying mesh data structures that primarily work on raw index buffers, vertex buffers and mesh subset data.

You can use `SetVertexBufferData` to set vertex data directly, without using format conversions for each vertex attribute. The supplied data layout has to match the vertex data layout of the mesh (see [Mesh.SetVertexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setvertexbufferparams.md), [Mesh.GetVertexAttributes](/engine/6000.3/script-reference/unityengine/mesh/getvertexattributes.md)). Partial updates of the data are also possible, via `dataStart`, `meshBufferStart`, `count` parameters.

```csharp
using UnityEngine;
using UnityEngine.Rendering;
using Unity.Collections;

public class Example : MonoBehaviour
{
    // Vertex with FP32 position, FP16 2D normal and a 4-byte tangent.
    // In some cases StructLayout attribute needs
    // to be used, to get the data layout match exactly what it needs to be.
    [System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential)]
    struct ExampleVertex
    {
        public Vector3 pos;
        public ushort normalX, normalY;
        public Color32 tangent;
    }

    void Start()
    {
        var mesh = new Mesh();
        // specify vertex count and layout
        var layout = new[]
        {
            new VertexAttributeDescriptor(VertexAttribute.Position, VertexAttributeFormat.Float32, 3),
            new VertexAttributeDescriptor(VertexAttribute.Normal, VertexAttributeFormat.Float16, 2),
            new VertexAttributeDescriptor(VertexAttribute.Tangent, VertexAttributeFormat.UNorm8, 4),
        };
        var vertexCount = 10;
        mesh.SetVertexBufferParams(vertexCount, layout);

        // set vertex data
        var verts = new NativeArray<ExampleVertex>(vertexCount, Allocator.Temp);

        // ... fill in vertex array data here...

        mesh.SetVertexBufferData(verts, 0, 0, vertexCount);
    }
}
```

Additional Resources: [Mesh.SetVertexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setvertexbufferparams.md), [Mesh.SetIndexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferparams.md), [Mesh.SetIndexBufferData](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferdata.md), [Mesh.SetSubMesh](/engine/6000.3/script-reference/unityengine/mesh/setsubmesh.md), [MeshUpdateFlags](/engine/6000.3/script-reference/unityengine/rendering/meshupdateflags.md), [Mesh.AcquireReadOnlyMeshData](/engine/6000.3/script-reference/unityengine/mesh/acquirereadonlymeshdata.md).

## SetVertexBufferData\<T>(\`\<>\[], int, int, int, int, MeshUpdateFlags)

Sets the data within a specific vertex buffer stream, copying elements from a source container to a destination range within the `Mesh`'s buffer.

```csharp
public void SetVertexBufferData<T>(T[] data, int dataStart, int meshBufferStart, int count, int stream = 0, MeshUpdateFlags flags = MeshUpdateFlags.Default) where T : struct
```

### Parameters

**** (\[\<T>\[]]\(./)): The source container from which vertex data is copied.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The first element in the data to copy from.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The first element in mesh vertex buffer to receive the data.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The number of elements of type `T` to copy from the `data` container into the [Mesh](/engine/6000.3/script-reference/unityengine/mesh.md) buffer.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): Vertex buffer stream to set data for (default 0). Value must be within range 0 to 3.**** (\[MeshUpdateFlags]\(/engine/6000.3/script-reference/unityengine/rendering/meshupdateflags)): Flags controlling the function behavior, see [MeshUpdateFlags](/engine/6000.3/script-reference/unityengine/rendering/meshupdateflags.md).

### Remarks

Simple usage of [Mesh](/engine/6000.3/script-reference/unityengine/mesh.md) scripting API involves using functions like [Mesh.vertices](/engine/6000.3/script-reference/unityengine/mesh/vertices.md), [Mesh.normals](/engine/6000.3/script-reference/unityengine/mesh/normals.md) to setup vertex data.

For advanced use cases that require maximum performance, you can use the advanced API, which has functions like [Mesh.SetSubMesh](/engine/6000.3/script-reference/unityengine/mesh/setsubmesh.md), [Mesh.SetIndexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferparams.md), [Mesh.SetIndexBufferData](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferdata.md), and [Mesh.SetVertexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setvertexbufferparams.md). This advanced API gives access to the underlying mesh data structures that primarily work on raw index buffers, vertex buffers and mesh subset data.

You can use `SetVertexBufferData` to set vertex data directly, without using format conversions for each vertex attribute. The supplied data layout has to match the vertex data layout of the mesh (see [Mesh.SetVertexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setvertexbufferparams.md), [Mesh.GetVertexAttributes](/engine/6000.3/script-reference/unityengine/mesh/getvertexattributes.md)). Partial updates of the data are also possible, via `dataStart`, `meshBufferStart`, `count` parameters.

```csharp
using UnityEngine;
using UnityEngine.Rendering;
using Unity.Collections;

public class Example : MonoBehaviour
{
    // Vertex with FP32 position, FP16 2D normal and a 4-byte tangent.
    // In some cases StructLayout attribute needs
    // to be used, to get the data layout match exactly what it needs to be.
    [System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential)]
    struct ExampleVertex
    {
        public Vector3 pos;
        public ushort normalX, normalY;
        public Color32 tangent;
    }

    void Start()
    {
        var mesh = new Mesh();
        // specify vertex count and layout
        var layout = new[]
        {
            new VertexAttributeDescriptor(VertexAttribute.Position, VertexAttributeFormat.Float32, 3),
            new VertexAttributeDescriptor(VertexAttribute.Normal, VertexAttributeFormat.Float16, 2),
            new VertexAttributeDescriptor(VertexAttribute.Tangent, VertexAttributeFormat.UNorm8, 4),
        };
        var vertexCount = 10;
        mesh.SetVertexBufferParams(vertexCount, layout);

        // set vertex data
        var verts = new NativeArray<ExampleVertex>(vertexCount, Allocator.Temp);

        // ... fill in vertex array data here...

        mesh.SetVertexBufferData(verts, 0, 0, vertexCount);
    }
}
```

Additional Resources: [Mesh.SetVertexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setvertexbufferparams.md), [Mesh.SetIndexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferparams.md), [Mesh.SetIndexBufferData](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferdata.md), [Mesh.SetSubMesh](/engine/6000.3/script-reference/unityengine/mesh/setsubmesh.md), [MeshUpdateFlags](/engine/6000.3/script-reference/unityengine/rendering/meshupdateflags.md), [Mesh.AcquireReadOnlyMeshData](/engine/6000.3/script-reference/unityengine/mesh/acquirereadonlymeshdata.md).

## SetVertexBufferData\<T>(List\<T>, int, int, int, int, MeshUpdateFlags)

Sets the data within a specific vertex buffer stream, copying elements from a source container to a destination range within the `Mesh`'s buffer.

```csharp
public void SetVertexBufferData<T>(List<T> data, int dataStart, int meshBufferStart, int count, int stream = 0, MeshUpdateFlags flags = MeshUpdateFlags.Default) where T : struct
```

### Parameters

**** (\[List\<T>]\(https\://learn.microsoft.com/dotnet/api/system.collections.generic.list-1)): The source container from which vertex data is copied.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The first element in the data to copy from.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The first element in mesh vertex buffer to receive the data.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The number of elements of type `T` to copy from the `data` container into the [Mesh](/engine/6000.3/script-reference/unityengine/mesh.md) buffer.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): Vertex buffer stream to set data for (default 0). Value must be within range 0 to 3.**** (\[MeshUpdateFlags]\(/engine/6000.3/script-reference/unityengine/rendering/meshupdateflags)): Flags controlling the function behavior, see [MeshUpdateFlags](/engine/6000.3/script-reference/unityengine/rendering/meshupdateflags.md).

### Remarks

Simple usage of [Mesh](/engine/6000.3/script-reference/unityengine/mesh.md) scripting API involves using functions like [Mesh.vertices](/engine/6000.3/script-reference/unityengine/mesh/vertices.md), [Mesh.normals](/engine/6000.3/script-reference/unityengine/mesh/normals.md) to setup vertex data.

For advanced use cases that require maximum performance, you can use the advanced API, which has functions like [Mesh.SetSubMesh](/engine/6000.3/script-reference/unityengine/mesh/setsubmesh.md), [Mesh.SetIndexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferparams.md), [Mesh.SetIndexBufferData](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferdata.md), and [Mesh.SetVertexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setvertexbufferparams.md). This advanced API gives access to the underlying mesh data structures that primarily work on raw index buffers, vertex buffers and mesh subset data.

You can use `SetVertexBufferData` to set vertex data directly, without using format conversions for each vertex attribute. The supplied data layout has to match the vertex data layout of the mesh (see [Mesh.SetVertexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setvertexbufferparams.md), [Mesh.GetVertexAttributes](/engine/6000.3/script-reference/unityengine/mesh/getvertexattributes.md)). Partial updates of the data are also possible, via `dataStart`, `meshBufferStart`, `count` parameters.

```csharp
using UnityEngine;
using UnityEngine.Rendering;
using Unity.Collections;

public class Example : MonoBehaviour
{
    // Vertex with FP32 position, FP16 2D normal and a 4-byte tangent.
    // In some cases StructLayout attribute needs
    // to be used, to get the data layout match exactly what it needs to be.
    [System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential)]
    struct ExampleVertex
    {
        public Vector3 pos;
        public ushort normalX, normalY;
        public Color32 tangent;
    }

    void Start()
    {
        var mesh = new Mesh();
        // specify vertex count and layout
        var layout = new[]
        {
            new VertexAttributeDescriptor(VertexAttribute.Position, VertexAttributeFormat.Float32, 3),
            new VertexAttributeDescriptor(VertexAttribute.Normal, VertexAttributeFormat.Float16, 2),
            new VertexAttributeDescriptor(VertexAttribute.Tangent, VertexAttributeFormat.UNorm8, 4),
        };
        var vertexCount = 10;
        mesh.SetVertexBufferParams(vertexCount, layout);

        // set vertex data
        var verts = new NativeArray<ExampleVertex>(vertexCount, Allocator.Temp);

        // ... fill in vertex array data here...

        mesh.SetVertexBufferData(verts, 0, 0, vertexCount);
    }
}
```

Additional Resources: [Mesh.SetVertexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setvertexbufferparams.md), [Mesh.SetIndexBufferParams](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferparams.md), [Mesh.SetIndexBufferData](/engine/6000.3/script-reference/unityengine/mesh/setindexbufferdata.md), [Mesh.SetSubMesh](/engine/6000.3/script-reference/unityengine/mesh/setsubmesh.md), [MeshUpdateFlags](/engine/6000.3/script-reference/unityengine/rendering/meshupdateflags.md), [Mesh.AcquireReadOnlyMeshData](/engine/6000.3/script-reference/unityengine/mesh/acquirereadonlymeshdata.md).