Warp and Blend
Warp and Blend are interfaces exposed in NVAPI for warping (image geometry corrections) and blending (intensity and black level adjustment) a single display output or multiple display outputs
Many display applications benefit from combining multiple projectors or displays into one larger display surface. If all the displays are aligned in a grid with no overlap, features like Mosaic make it easy to create a single unified display from multiple physical displays. When the displays are rotated at odd angles or the display surface is an irregular shape, multiple projectors need to overlap, blend together and be mapped or adjusted to the display surface. The Warp and Blend SDK provides an easy way to bring this functionality to any application with minimal performance impact and no incremental latency.
In the example above both warp and blend are used to achieve a seamless, blended picture from two projectors illuminating a curved screen. A standard practice when using multiple projectors is to overlap the seams where each projected image touches another. Since optics and screens are never perfect and overlapping can create hotspots (regions gets twice amount of light) blend is used to adjust the intensity of the overlapping region. Warp is used to modify geometry so that it matches the curve of the projection wall.
Traditionally, warp and blend operations are done with custom hardware using features built into the projector or with direct modifications to an application. The Warp and Blend SDK provides an easy way to bring this functionality to any application with minimal performance impact and no incremental latency.
Warp and Blend is part of NVAPI
NVAPI is NVIDIA's core software development kit that allows direct access to NVIDIA GPUs on windows platforms. Warp and blend is implemented as an interface in NVAPI that programmably exposes warping and intensity adjustment features before the final scanout. Working in conjunction with a supported NVIDIA Display Driver, the warp and blend features works on a single screen, multiple screens and multi-gpu configurations and are available only with NVIDIA Quadro GPUs.
Learn more about NVAPI.
Download Warp and Blend Sample
Download the Warp and Blend programming sample package to get started developing with warp and blend and NVAPI. To download, you must be a member of NVIDIA Developer - DesignWorks.
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- Generate a seamless image on up to 16 displays or projectors with warp and blend using NVIDIA Mosaic Technologies and NVIDIA Quadro Sync (ability to synchronize up to four Quadro GPUs per system).
- Apply warping to any scenario that requires image geometry corrections such as rotation, skew, mirroring, offset, and geometry mapping.
- Adjust intensity and black level in portions of a screen, every pixel if desired.
- Minimal performance impact and no incremental latency.
- Works in single screen, multiple screens and multi-gpu configurations.
|Windows 7, 8, 10, Server 2008R2, Server 2012
|NVIDIA Quadro 1200 class or higher products with Fermi, Kepler, Maxwell or newer GPUs
NVS 810 & 510
Windows Quadro Display drivers 302.82 or newer
Why do Warp and Blend on the GPU?
Traditionally, warp and blend is integrated into the projector or done using custom hardware appliances which adds performance delay to the display pipeline. It can also be done using software applications but that may not conform to all use cases. Since the pixel information is already available to the GPU, the GPU is the natural place to do this work. GPUs also bring additional benefits to warp and blend:
- GPUs are inherently parallel for fast image processing operations
- Ability to perform transformation in the display pipeline before the pixel get scanned out
- Minimal performance delay to display pipeline compared to external boxes using FPGAs
- Cost effective and easily scalable
Warp and Blend In Action
Immersive VR using a domed screen
The Operational Based vision Assessment (OBVA) Simulator at NASA.
Image courtesy of NASA
Projection mapping onto scale physical models
A 1:5 scale, blank canvas model car with car’s features projected onto the surface of the model to replicate a photo-real, physical object for real-time interaction and customization.
Image courtesy of Christie Digital
Simulator environment with large curved front displays
The PanoLab is a wide-area high realistic projection system for interactive presentations of virtual environments. The half-spherical screen of PanoLab allows the simulation of large visual fields providing an increased degree of immersion. The PanoLab was calibrated using nWarp, part of the ProjectionTools automatic calibration system from domeprojections.com
Image courtesy of Joachim Tesch. Max Planck Institute for Biological Cybernetics.
Multi-projection display walls
Using a matrix of projections projected to a single screen to present a seamless large scale, single image.
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Warp and Blend Presentations
Update on Warping Standards