GPU-Based Visualization
for Flight Simulation
Tim Woodard
Director of Research and Development
Diamond Visionics
www.dvcsim.com
GPU Technology Conference 2014
Flight Simulation Takes Off
Flight Simulation Takes Off
Link’s Blue Box, 1943
Flight Simulation Takes Off
Link’s Blue Box, 1943
Terrain model-board and
film, 50’s and 60’s
Flight Simulation Takes Off
Link’s Blue Box, 1943
Terrain model-board and
film, 50’s and 60’s
“Image Generators”, 70’s
to present
“Big Iron”
McDonnell Douglas VITAL
Evans and Sutherland ESIG
GE Compu-scene
Link DIG
SGI Onyx
Improved rapidly
“Big Iron”
McDonnell Douglas VITAL
Evans and Sutherland ESIG
GE Compu-scene
Link DIG
SGI Onyx
Improved rapidly, but
costly…
Rise of the PC
McDonnell Douglas (VITAL)
Evans and Sutherland (ESIG)
GE (Compu-scene)
Link (DIG)
Improved rapidly, but VERY costly…
1999, NVIDIA GeForce 256
Rise (and fall?) of the PC
Moving to the PC-based GPU brought huge cost savings
Rise (and fall?) of the PC
Moving to the PC-based GPU brought huge cost savings
But meant giving up a lot of capability and control
Real-time determinism
Anti-aliasing
Gen-lock
Unified memory
Computational power
Flight Simulation vs. Gaming
Instructor-controlled conditions (time, weather, etc.)
Subjective tuning
Fidelity
No aliasing
No Z-fighting
No LOD popping
Performance
Never drop frames
20+ channels
Data…
Flight Simulation vs. Gaming
Large gaming areas – “database”
(E.g. continental, even planetary)
Legacy database standards
(Government-defined)
Typical gaming approaches do not
scale to massive datasets... (nor do
traditional simulation approaches)
Throw Hardware At It!
Moore’s Law continues…
…Via parallelism, not speed
(for nearly 10 years now)
First with CPU, now with
GPU
Not So Fast
Free lunch is over…
Software must be architected for
parallelism: Amdahl’s Law
𝑆=
1
𝑃
(1 − 𝑃) +
𝑛
S = speed up
P = % of parallelization
n = number of threads
The Long Pole
Prepare
Source Data
Compile
Database
Re-work
Intermediate Database
(LODs)
Load/Render
Database
Compute ALL the LODs!
Pre-compute LODs for all possible
paths into “polygon soup”
Very little of the result is typically
used
Compute ALL the LODs!
Pre-compute LODs for all possible
paths into “polygon soup”
Very little of the result is typically
used
Uses tremendous computing
resources
Uses tremendous amount of
storage space
Stuck in Time
Static databases do not adapt to new data or GPU technology
Stuck in Time
Static databases do not adapt to new data or GPU technology
Stuck in Time
Static databases do not adapt to new data or GPU technology
Underutilizes GPU
Leveraging the GPU
Large/fast memory buffers
Programmability…
Vertex, fragment, geometry
Compute
Run-time Scene Generation
Prepare
Source Data
Source Data
User-Defined
Processing Rules/
Shaders
Load/Render
Source Data on
GPU
Deferred Commitment
Case Study: Hardware Consolidation
One 4K projector from one GPU
Multiple GPUs per system
Case Study: Lights
~50 tunable
parameters
100’s of thousands
of lights possible at
60Hz
Case Study: Grass
10’s of thousands
of grass blades
Matches imagery
color
Local wind model
(helo rotor wash)
Summary
Visualization in flight simulation continues to evolve rapidly.
GPU advancements have fundamentally changed how we do
things and what is possible:
Improved fidelity
Improved performance
Deferred commitment, instant feedback
Questions?
Tim Woodard
timw@dvcsim.com
@TimAtDVC #GTC14
Thank you!