Recent Methods forImage-based Modeling and Rendering

Lecture 6: Rendering

Darius BurschkaDarius BurschkaJohns Hopkins UniversityJohns Hopkins University

Dana CobzasDana CobzasUniversity of Alberta University of Alberta

Zach DoddsZach DoddsHarvey Mudd CollegeHarvey Mudd College

Martin JagersandMartin JagersandUniversity of Alberta University of Alberta

Keith YerexKeith YerexVirtual Universe CorporationVirtual Universe Corporation

IEEE VR 2003 tutorial 1

Implementation

•Matlab for geometric modeling and prototypingMatlab for geometric modeling and prototyping

•mexVision for tracking (30Hz frame rate)mexVision for tracking (30Hz frame rate)

•Hardware accelerated OpenGL for rendering Hardware accelerated OpenGL for rendering (2.8Hz in SW, 18Hz on GeForce 2)(2.8Hz in SW, 18Hz on GeForce 2)

•pthreads and pvm for parallel processingpthreads and pvm for parallel processing

MATLAB

meXVision OpenGL

Hardware rendering

•Unsigned basisUnsigned basis

•Scaling to 8 bitScaling to 8 bit

•WhereWhere

I w(t) = B+y(t) à Bày(t) + Iö

Bà+ =255B+ðà 1

Bàà =255Bàðà 1

yà =255à 1ðy

ð= diag(maxjBj)

OpenGL==draw the meanBi ndTexture(Iö);DrawTr i angl es();==add basi s t exturesf or (each i)fSetBl endCoef f i ci ent (jyài(t)j);Bi ndTexture(Bà+

i );i f (yài(t) > 0)SetBl endEquat i on(ADD);el se SetBl endEquat i on(SUBTRACT);DrawTr i angl es();Bi ndTexture(Bàà

i );i f (yài(t) > 0)SetBl endEquat i on(SUBTRACT);el se SetBl endEquat i on(ADD);DrawTr i angl es();

g

Geometric SFM and dynamic textures

I1 It

…

= =

+ +

Warped texture

Motion params

(R1 a1 b1) …(Rt at bt)

Structure P

Texture basis

y1 … yt

Texture coeff

New pose

(R a b)

Training Model New view

uv

ô õ= RP + a

b

ô õ

I wt = Byt + IöI wqt = I qt(W(ut;vt))

I wt =P

q=1Q I wqt

I t =P

q=1Q I qt

(Cobzas, (Cobzas, Yerex Yerex Jagersand Jagersand 2002)2002)

Capture system

•Video and visual tracking from and ieee1394 camVideo and visual tracking from and ieee1394 cam

•Based on XVision2, PVM and Capture UIBased on XVision2, PVM and Capture UI

Structure editor

•Verify geometric structure reprojectionsVerify geometric structure reprojections

•Edit tracking errorsEdit tracking errors

Triangulation and Texture Editor

•Adjust Delauney Adjust Delauney triangulationtriangulation

•Adjust texture Adjust texture resolution for resolution for individual trianglesindividual triangles

Real-Time Renderer

•Real-Time HW implementation of texture Real-Time HW implementation of texture blending in NVIDIA register combinersblending in NVIDIA register combiners