Stereoscopy for Non-Planar Projections (TRUE 3D 2009)
- 1. Enhancing Interactive Non-Planar Projections of 3D Geovirtual Environments with Stereoscopic ImagingMatthias Trapp, Haik Lorenz, Markus Jobst, Jürgen DöllnerHasso-Plattner-Institute at the University of PotsdamTrue-3D in Cartography1st International Conference on 3D MapsAugust 24 - 28, 2009 Dresden, Germany1
- 2. motivationgeo-media technology provides interactivity, immersionfacilitatesthecommunication of 3D geospatialdataapplications to cartography:increase immersion into 3D geovirtual environmentssupport for depth-cuesplanar stereoscopy:well understood – rendering: straight forwardsupported by graphics hardware / drivernon-planar stereoscopy:provides high field-of-view and image resolution2
- 3. problem: non-planar projection surfacesrendering of digital 3D city and landscape models:high amount of geometry and texture datareal-time constraints (> 20 frames per second)current generation of graphics hardware (GPU)no native support for non-planar projection surfacesrequires specific rendering techniquesclassified into image, geometry, and ray-based approacheshardware-accelerated stereoscopic imaging:available stereo hardware modifies vertex pipeline stage cannot be used for rendering non-planar stereoscopy3
- 4. framework - conceptual overview4
- 5. review: image-based approach (IBA)basic concept:dynamic cube map + screen-aligned quadimage warping based on normal vectors:3-phase rendering process: create/update dynamic cubemap setup projection shader render screen-aligned quad5
- 6. adapting IBA for stereoscopybasic idea for image-based non-planar projections:create cubemaps for each virtual cameraderive non-planar projection for each cube-mapexamplary workflow for two stereo mates:6
- 7. review: geometry-based approach (GBA)projection computed on a per-vertex basisensure sufficient on-screen vertex densitydynamic mesh refinement required7
- 8. adapting GBA for stereoscopystraight forward approach:setup piece-wise projection for each virtual camerarender into different color-buffersadditional post-processing step: layer compositingexample for stereo image pairs:8
- 9. rendering active & passive stereoactive stereo:using quad-buffering usually encapsulated by graphics driver passive stereo:anaglyph: color-buffer compositingpolarized: render to framebufferchromo-depth stereo: apply directly during rendering9
- 10. rendering passive anaglyph - resultsHITIT10
- 11. rendering chromo-stereoscopyno need for generating stereo image paircolor as a function of depth11
- 12. rendering chromo-stereoscopy - resultsHITIT12
- 13. applying chromo-stereoscopyGBA: straight forward application to fragment‘s depthIBA: needs depth correction13
- 15. chroma-stereoscopy issuescommon problems for IBA and GBA:distribution of color can decrease stereo effectperception: facade information (texture) is alteredinteraction: focal plane must be adapted15
- 16. binarycomparision GBA vs. IBA16
- 17. conclusions & future workconclusions:interactive stereoscopic rendering for non-planar projectionsincreases immersion, thus psychological depth cuesperformance limited by geometric complexity of the sceneGBA outperforms IBA but IBA much easier to implement/useopen problem:omni-directional stereo without image artifactsfuture work:auto stereoscopy for non-planar projections surfaceseye tracking to adjust user‘s focal plane17
- 18. Thank you for your attention! Questions?ContactMatthias [email protected] [email protected] [email protected]ürgenDö[email protected] 3D Geoinformationwww.3dgi.de/Computergraphics System Groupwww.hpi.uni-potsdam.de/doellner/18
Editor's Notes
- #11: IBA360 degreecylindricalprojectionRendererusinganaglyphstereoimagingAntennas: samplingartifactsProblem: noomni-directionalstereopossible
- #12: Anotherinstanceof passive stereoscopyischromo-stereoscopy.
- #13: Sphericalprojection[CLICK]
- #14: Therearedifferencesofapplyingchromo-stereoscopytoto IBA and GBA.Whilethecolormappingcanbeapplieddirectlytotheresults
- #15: Thisworks alsousing different colorramps – thatcanbeswitchedatruntimeA problemthatyoucansee in thisvideo: thedistributionofcolors – canlacks[CLICK]
- #16: Wehavetofacesomecommonproblemswhenapplyingchromo-stereoscopyto 3D geovirtualenvironments