Interactive Reflection Editing

Tobias Ritschel Makoto Okabe Thorsten Thormählen Hans-Peter SeidelMax-Planck-Institut Informatik

SIGGRAPH Asia 2009Friday, 18 December, 2009, Yokohama, Japan

Interactive Reflection Editing (Ritschel et al.)

MOTIVATIONView direction

Physical reflection

Edited reflection

The Rokeby Venus (before 1651, detail)Diego Velasquez (1599-1660)

Interactive Reflection Editing (Ritschel et al.)

MOTIVATION

Interactive Reflection Editing (Ritschel et al.)

PREVIOUS WORK

Light paintingSchöneman et al. 1993Poulin et al. 1997Pellacini et al. 2007Obert et al. 2008

Appearance editingColbert et al. 2006Kautz et al. 2007Anjyo et al. 2003Todo et al. 2004

Lighting optimizationShacked and Lischinski 2001Rusinkiewicz et al. 2008

Interactive Reflection Editing (Ritschel et al.)

PREVIOUS WORK

Intuitive deformationIgarashi et al. 2005Müller et al. 2005Schaefer et al. 2006Sorkine and Alexa 2007

Inhouse SolutionsUnpublishedBuild-your-own, using e.g. Kopra 2007

Reflection PerceptionFleming et al. 2003Ramanarayana et al. 2005Khan et al. 2006

Interactive Reflection Editing (Ritschel et al.)

Viewer

Reflecting object

Reflected object

PHYSICAL LAWSPhysical Reflection

View direction

Normal

Edited Reflection

Interactive Reflection Editing (Ritschel et al.)

INTERACTION

Original Edit 1 Edit 2

Interactive Reflection Editing (Ritschel et al.)

INTERPOLATION

Schaefer et al. 2006 interpolaterotation / translation ofpixelsin 2D.

We interpolaterotations ofreflection directionson a 3D surface.

Interactive Reflection Editing (Ritschel et al.)

INTERPOLATION

Transformation

Number of constraints Original ray n Edited ray n

Position inquestion

Weight n

Edit position n

Distance(Euclidean or geodesic)

Interactive Reflection Editing (Ritschel et al.)

INTERPOLATION

Weight n Reflection n

Edited reflection n

Enforcing rotation

Interactive Reflection Editing (Ritschel et al.)

GPU IMPLEMENTATION• Solve R(q) per fragment q under all constraints using a GPU• 24.5 megapixels / s on a Nvida GeForce 8800 GTX

Interactive Reflection Editing (Ritschel et al.)

APPLICATIONS

Reflection edit: Kitchen

Reflection edit: Ring

Reflection edit: Car

Highlight Editing

Refraction Editing

Interactive Reflection Editing (Ritschel et al.)

CAR

Interactive Reflection Editing (Ritschel et al.)

KITCHEN

Interactive Reflection Editing (Ritschel et al.)

RING

Interactive Reflection Editing (Ritschel et al.)

HIGHLIGHT EDIT

Interactive Reflection Editing (Ritschel et al.)

REFRACTION EDIT

Interactive Reflection Editing (Ritschel et al.)

KEYFRAMED ANIMATION

Interactive Reflection Editing (Ritschel et al.)

USER STUDY

Study 1: Task performance

Study 2: Visual quality

Interactive Reflection Editing (Ritschel et al.)

TASK PERFORMANCE

• 16 novice users• Task: “Reproduce this example result image we made” performed in

• 2:22 minutes for “Rokeby Dragon”• 4:04 minutes for “Kitchen”• 2:00 minutes for “Highlight”

Interactive Reflection Editing (Ritschel et al.)

VISUAL QUALITY

Interactive Reflection Editing (Ritschel et al.)

VISUAL QUALITY

Aver

age

scor

e

Edits

Original

Edits

Result:Users consider non-physical reflections plausible forsignificant and meaningful edits.

Interactive Reflection Editing (Ritschel et al.)

FUTURE WORK

Problem: Can do unpleasant and unrealistic editsSolution: Restrict to pleasant and realistic edits. How?

Problem: Bending rays is not possibleSolution: Allow it. Mostly a UI problem.

Problem: Limitation to reflectionsSolution: Try for other phenomena such as shadows, bounces, or caustics

Interactive Reflection Editing (Ritschel et al.)

CONCLUSION

You saw a system, that …… allows to edit rendered reflections as artists did for centuries.… is easy to use and implement and runs in real-time.… was evaluated in a user-study.

You can test it at the Digital Bazaar A60

Interactive Reflection Editing (Ritschel et al.)

THANK YOU!

Acknowledgemens

Max-Planck Center for Visual Computing and Communication BMBF-FKZ01IMC01Anthonny DickMartin FuchsCarsten StollKaleigh SmithStudy participants

FundingVoice-overInternal ReviewInternal ReviewInternal ReviewPatience

Interactive Reflection Editing (Ritschel et al.)

SURFACE DETAILS

Interactive Reflection Editing (Ritschel et al.)

LAFORTUNE

Interactive Reflection Editing (Ritschel et al.)

CHEATING