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# MTLAccelerationStructureMotionTriangleGeometryDescriptor

A description of a list of triangle primitives, as motion keyframe data, to turn into an acceleration structure.

```
class MTLAccelerationStructureMotionTriangleGeometryDescriptor
```

## Topics

### Creating a triangle motion geometry descriptor

[`descriptor`](/documentation/Metal/MTLAccelerationStructureMotionTriangleGeometryDescriptor/descriptor)

Creates a new triangle descriptor.

### Specifying the number of triangles

[`triangleCount`](/documentation/Metal/MTLAccelerationStructureMotionTriangleGeometryDescriptor/triangleCount)

The number of triangles in the buffers.

### Specifying index data

[`indexBuffer`](/documentation/Metal/MTLAccelerationStructureMotionTriangleGeometryDescriptor/indexBuffer)

A buffer that contains indices for the vertices that compose the triangle list.

[`indexType`](/documentation/Metal/MTLAccelerationStructureMotionTriangleGeometryDescriptor/indexType)

The data type of indices in the index buffer.

[`indexBufferOffset`](/documentation/Metal/MTLAccelerationStructureMotionTriangleGeometryDescriptor/indexBufferOffset)

The offset, in bytes, to the first index in the buffer.

### Specifying vertex data

[`vertexBuffers`](/documentation/Metal/MTLAccelerationStructureMotionTriangleGeometryDescriptor/vertexBuffers)

An array of motion keyframes, each containing triangle data.

[`vertexStride`](/documentation/Metal/MTLAccelerationStructureMotionTriangleGeometryDescriptor/vertexStride)

The stride, in bytes, between vertices in each vertex buffer.


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