Increases in pixel density and total pixels have not kept pace with increases in CPU and GPU power. Some of the solutions to adding more pixels:
- LCDs – Obtrusive bezels in the way
- Nearly bezel-less
- Projectors overlap the edges to hide the seam. This creates a hotspot since the overlap region gets twice the light:
- How to project on dome and curved screens?
Currently Nvidia Mosaic allows you to specify overlap. But to be truly seamless, there is a need to account for geometry and brightness differences between projectors.
The Solution: Warp and Blend
- Warp: Geometry corrections
- Blend: Intensity adjustments
Up until now, warp and blend for projection displays has been done in one of the following two ways:
- Hardware appliance for warp and intensity adjustment
- Extra-performance delay tax on the display pipeline
- Additional complexity
- Software warp and intensity adjustment
- Applications need to be written to manage the display for every use-case
- There has not been an easy way to implement this for any application, until now…
NVIDIA can do this on the GPU, which has several important advantages:
- GPUs are fast and already have the pixel information
- GPUs perform the transformation in the display pipeline before the pixels get scanned out
- By doing this on the GPU we have more flexibility: high quality filtering, integration with NVIDIA Mosaic, etc.
- Works on Quadro 5000, 6000, and Quadro Plex 7000
- Use it with G-sync to get synchronization between displays
How Is It Done: Workflow
- Take a picture of calibration pattern
- Create warping mesh based on picture of the calibration pattern relative to the true image
- Typical warping mesh contains 1K to 10K vertices
How Is It Done: NVAPI
- NVAPI is Nvidia’s programmatic interface to configure and control the GPU’s – http://developer.nvidia.com/nvapi.
- New interfaces are added in the 275+ NDA version to allow warping and intensity adjustment before the final scanout.
- Currently it works with single screen. Multiple screen capability coming with R285 driver (mid September)
How Is It Done: Warping
- Initialize NVIDIA
- Get GPU handle
- Get display ID
- Define warping mesh
- Use NvAPI_GPU_GetScanoutConfiguration() to get current desktop
- Each vertex has:
- x,y: 2D vertex coordinates
- u,v: 2D Texture coordinates
- r,q: Perspective correction
- Call NvAPI_GPU_SetScanoutWarping
How Is It Done: Blending (Intensity Adjustment)
- Initialize NVAPI
- Get GPU handle
- Get display ID
- Define Intensity Map: GL_RGB value for each pixel
- Call NVAPU_GPU_SetScanoutIntensity
Scalable Display Technologies
Leading provider of auto-calibration software for seamless multiple-projectors displays. Founded in 2004, based on P.h.D. work of Rajeev Surati at MIT. Scalable has over 100 customers in the following markets:
- Command and Control
- Business Collaboration
- Simulation and Training
- Pro A/V
- Projector OEMs: 70,000+ licenses
Core Auto-Calibration Technology
Camera-feedback to automatically warp and blend many projectors into one seamless display:
Benefits of the NVIDIA Warp and Blend API
Scalable Display Manager – Military & Simulation, Command & Control
- No longer need of SDK integration
- No need for expensive warping hardware
- Application independent
- Quadro support for Gen-lock
Fewer requirements, barriers and restrictions mean broader market and stronger growth.
ScalableDesktop (warped Win7 Desktop)
- Full integrations with Windows
- Eliminates mouse pointer issues
- Performance benefits
- Expands potential outputs to 24
AFRL – 100 MegaPixel Space Command and Control
25 Computers with Quadro cards running 50 projectors. Custom SDK integration that can run a single application; application independence with NVAPI warp and blend API.
Navy Combat System Display
Aegis Combat System Display: 22 Cruisers have been delivered and there are 62 Destroyers to follow with systems in U.S, Japan, Spain, Norway, Korea and Australia. Required Gen-Lock and SDK integration.
MIT Lincoln Labs – 20MPixel Touch Wall
12 Projectors systems using dual Quadroplexes, it is a prototype design for a virtual shopping aisle system. It will be the first install to use NVIDIA warp and blend API.
AFRL – 48 MPixel F-16 Simulator
This “Low Cost” simulator ($500K) by Immersive Display Solutions and using Scalable software, requires no warping box hardware which helps keep costs down. The application independence is essential to make it a “turn key” solution.
- Scalable Display Technologies is leader in auto-calibration for multi-projector displays.
- NVAPI Warp and Blend API makes our technology application independent.
- Fewer requirements, barriers and restrictions means broader market.
- Full Windows integration.