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# radiusBuffer

Assigns a reference to a buffer containing the curve radius for each control point.

```
var radiusBuffer: MTL4BufferRange { get set }
```

## Discussion

Metal interpolates curve radii according to the basis function you specify via [`curveBasis`](/documentation/Metal/MTL4AccelerationStructureCurveGeometryDescriptor/curveBasis).

You are responsible for ensuring the type of each radius matches the type property [`radiusFormat`](/documentation/Metal/MTL4AccelerationStructureCurveGeometryDescriptor/radiusFormat) specifies,
that each radius is at least zero, and that the buffer address of the range is not zero.

---

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