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Range Profile Synthesis. SAMPL Group Meeting 10 October 2000 By Gerald Dalley. Overview. Project Goal Ray Tracing Range Profiles and Range Images Lighting Models POV-Range. Project Goal. “Tanks Under Trees”. Ray Tracing -- 2D. Object Intersected. Screen. d s. x o. x s. . d o. - PowerPoint PPT Presentation
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Range Profile SynthesisRange Profile Synthesis
SAMPL Group MeetingSAMPL Group Meeting
10 October 200010 October 2000
By Gerald DalleyBy Gerald Dalley
OverviewOverview
Project GoalProject Goal Ray TracingRay Tracing Range Profiles and Range ImagesRange Profiles and Range Images Lighting ModelsLighting Models POV-RangePOV-Range
Project GoalProject Goal
““Tanks Under Trees”Tanks Under Trees”
Ray Tracing -- 2DRay Tracing -- 2D
Ray Tracing -- Math in 2DRay Tracing -- Math in 2D
Screen
Object Intersected
d s
do
xo
xs
ss
oo x
d
dx s
s
oo x
d
dx
Ray Tracing -- 3DRay Tracing -- 3D
Range Profiles -- Range Profiles -- TheoryTheory
Range Profiles -- Range Profiles -- Current Current ImplementationImplementation
Range ImagesRange Images
Intensity
Range
Typical Lighting ModelTypical Lighting Model
AmbientAmbient• Background light levelBackground light level
DiffuseDiffuse• Matte surfaceMatte surface
SpecularSpecular• The window on the appleThe window on the apple
Bidirectional Radiance Bidirectional Radiance Distribution Functions (BRDFs)Distribution Functions (BRDFs)
Plane of reflection
Plane of IncidenceSurface Normal
r
i
i
r
Figure adapted from Advanced Animation and Rendering Techniques, pg. 34
BRDFs Cont.BRDFs Cont.
Physics-based lightingPhysics-based lighting• Polarized lightPolarized light
Example: Wet pavementExample: Wet pavement
i r
i and r both small
BRDF SimplificationsBRDF Simplifications
Intensity independent of: i (no polarization on incoming light)
r (no polarization on outgoing light)
i=r (light source and camera at same point)
I(i, r, i, r) I()
POV-RangePOV-Range
What is it?What is it? What platforms?What platforms? Performance?Performance?
• 800x600: 800x600: 20 min. /20 min. /
72 frames 72 frames• 8192x8192: 8192x8192:
6.5 hrs. / 6.5 hrs. / 1 frame1 frame
DemoDemo
““POV-Range”POV-Range”
View range image in MatlabView range image in Matlab
Further Information…Further Information…
Foley, Van Dam, Feiner, Hughes. Foley, Van Dam, Feiner, Hughes. Computer Computer Graphics: Principles and PracticeGraphics: Principles and Practice
Watt, Watt. Watt, Watt. Advanced Animation and Advanced Animation and Rendering TechniquesRendering Techniques
www.povray.orgwww.povray.org comp.graphics.rendering.comp.graphics.rendering.raytracingraytracing