bullet ray vision n.
Skip this Video
Loading SlideShow in 5 Seconds..
Bullet Ray Vision PowerPoint Presentation
Download Presentation
Bullet Ray Vision

Loading in 2 Seconds...

play fullscreen
1 / 13

Bullet Ray Vision - PowerPoint PPT Presentation

  • Updated on

Bullet Ray Vision. Lee A. Butler US Army Research Laboratory Abe Stephens University of Utah SCI Institute. Genesis. Contract to MAGI in 1966* Observation: projectiles passing through matter have similarity to photons passing through lenses.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

Bullet Ray Vision

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
bullet ray vision

Bullet Ray Vision

Lee A. Butler

US Army Research Laboratory

Abe Stephens

University of Utah

SCI Institute

  • Contract to MAGI in 1966*
    • Observation: projectiles passing through matter have similarity to photons passing through lenses.
  • MAGI later developed Synthavision and did most of the rendering for TRON(1982).
  • Photon transport was adapted to ballistic penetration. The threat replaced the photon. The target replaced the lens.
  • Ballistic penetration is like participating media. As the penetration occurs, there is interaction with the target media. Both the threat and the target are affected by the interaction.
  • Computation is performed on the entire ray/object intersection, not just at the surface.
    • CSG was a natural geometric representation.
original design
Original Design
  • Everything is expensive to compute, so allow everything to be re-used
    • Ray-geometry intersection was computed and saved for re-use. Typically, penetration equations and parameters were altered for each use.
    • Assumes a single ray/threat relationship.
  • V50:Velocity at which 50% of fragments will penetrate:

V50(ft/sec) = 10c (h(in) Af(in2))

Wf(grains) sec 

  • Residual Velocity:

Vr(ft/sec) = V(ft/sec)– 10c (h  Af) 

Wf sec  V(ft/sec)

  • Residual Weight:

Wr(grains) = Wf– 10c (h  Af) 

Wf sec  V

cultural evolution
Cultural Evolution
  • Programmer-user to Application-user.
  • Data re-use to application re-run.
  • Single ray/threat relationship to multiple rays/threat relationship.
  • Ray tracing slow to fast
one step forward
Interleave ballistic penetration calculations with ray/geometry intersection using classic BRL-CAD ray-tracer on CSG geometry.

Nice performance improvement, but still slow.

One Step Forward

View Computation Time (seconds)

two steps forward
Bullet Vision:

Since we’re ray tracing, render the results of the computation too. Free visualization!

Two Steps Forward
three steps forward
Implement computation as a shader in Manta packet-based ray tracer.

Need to collect in/out pairs before “shading.”

What was a batch application is now interactive. 3.9 fps on Intel Core 2 2.66Ghz with 4 cores.

Surprise: BVH Traversal is the major bottleneck in the system. “Shader” with 14 exponentiation operations is distinct second.

Three Steps Forward
future work
Future Work
  • Current work is a brute-force implementation of the penetration equations. 14 exponential operations.
  • There is ample opportunity to optimize the computation of the equations.
  • This is a equation fit to measured data. Alternative equation fits that are more computationally friendly are possible.
future work1
Future Work
  • BVH acceleration structure may not be optimal for applications where “transparent” geometry is the norm. Some further investigations on acceleration structures for such applications is needed.
  • Current frustum acceleration techniques may not be optimal for transparency and deferred shading algorithms.

US Army Research Laboratory

The Center for the Simulation of Accidental Fires and Explosions

(C-SAFE) B524196