# setViewports(_:) Configures the render pipeline with multiple viewports that apply transformations and clipping rectangles. ``` func setViewports(_ viewports: [MTLViewport]) ``` ## Parameters `viewports` An array of [`MTLViewport`](/documentation/Metal/MTLViewport) instances the command applies to the render pipeline for transformations and clipping. ## Discussion Use this method to configure multiple active viewports and corresponding scissor rectangles. Multiple viewports give your app the ability to draw into separate areas of an image with a single draw call. You can either set a single scissor rectangle for all viewports with the [`setScissorRect(_:)`](/documentation/Metal/MTLRenderCommandEncoder/setScissorRect(_:)) method, or set each viewport’s rectangle with the [`setScissorRects(_:)`](/documentation/Metal/MTLRenderCommandEncoder/setScissorRects(_:)) method. > Important: > The number of scissor rectangles you pass to ``doc://com.apple.metal/documentation/Metal/MTLRenderCommandEncoder/setScissorRects(_:)`` needs to match the number of viewports you configure with this method. The maximum number of viewports and scissor rectangles a GPU supports varies by device family. For more information, see [`MTLGPUFamily`](/documentation/Metal/MTLGPUFamily) and [Detecting GPU features and Metal software versions](/documentation/Metal/detecting-gpu-features-and-metal-software-versions). The rendering pipeline sends each primitive to a single viewport and its associated scissor rectangle. You can select which viewport each primitive uses in your vertex shader by adding the `[[viewport_array_index]]` attribute to an output value. The render pipeline linearly maps vertex positions from normalized device coordinates to viewport coordinates by applying a viewport during the rasterization stage. It applies the transform first and then rasterizes the primitive while clipping any fragments outside the scissor rectangle (see [`setScissorRect(_:)`](/documentation/Metal/MTLRenderCommandEncoder/setScissorRect(_:))) or the render target’s extents. The viewport’s [`originX`](/documentation/Metal/MTLViewport/originX) and [`originY`](/documentation/Metal/MTLViewport/originY) properties, which default to `0.0`, represent the number of pixels from the top-left corner of the render target. Positive [`originX`](/documentation/Metal/MTLViewport/originX) values go to the right and positive [`originY`](/documentation/Metal/MTLViewport/originY) values go downward. The default values for its [`width`](/documentation/Metal/MTLViewport/width) and [`height`](/documentation/Metal/MTLViewport/height) properties are the render target’s width and height, respectively. The default values for its [`znear`](/documentation/Metal/MTLViewport/znear) and [`zfar`](/documentation/Metal/MTLViewport/zfar) properties are `0.0` and `1.0`, respectively, which you can flip. > Note: > You can change the render pass’s viewport configuration by calling this method again or by calling the ``doc://com.apple.metal/documentation/Metal/MTLRenderCommandEncoder/setViewport(_:)`` method. The [`setViewport(_:)`](/documentation/Metal/MTLRenderCommandEncoder/setViewport(_:)) method is equivalent to calling this method with a single viewport element in the `viewports` array. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)