multiviewport

Multiviewport describes the design and rendering technique of presenting multiple independent view areas (viewports) within a single display or render target. Each viewport maps a portion of the output surface to a distinct camera, scene region, user interface panel, or video stream. The concept is widely used in split-screen multiplayer, computer-aided design and modeling applications, surveillance and monitoring systems, video walls, and immersive systems that require stereo or multi-camera outputs.

Implementations vary from simple software-managed layouts—where separate render passes draw into different rectangles of a framebuffer using scissor tests and viewport state—to more advanced GPU-supported methods. Modern graphics APIs provide viewport controls (for example, glViewport and viewport arrays in OpenGL, and comparable functions in Direct3D and Vulkan). Specialized features such as multiview or single-pass stereo allow a shader to produce multiple views in one rendering pass, reducing CPU/GPU overhead and improving synchronization between views.

Benefits include efficient space utilization, parallel presentation of different perspectives, and potential performance gains from single-pass techniques. Limitations and challenges include handling differing aspect ratios and resolutions across viewports, input-to-viewport mapping, increased shader complexity for multiview rendering, and varying hardware support for advanced single-pass features. Designers balance these trade-offs according to application requirements, target hardware, and user interaction models.