Querying GIS with Animated Spatial Sketches Volker Haarslev and Michael Wessel University of Hamburg, Germany haarslev@informatik.uni-hamburg.de http://kogs-www.informatik.uni-hamburg.de/~haarslev/ Motivation • VISCO's Language Elements • Sketching Queries for City Map Examples • Conclusion • (Demo Slides) • Vo lke r Haarslev, Se pte mbe r 97
Motivation Query Spatial Databases (GIS) Sketch constellation of spatial objects • Sketch constellation of spatial objects • Building • Topological and geometric • Topological and geometric relationships between components relationships between components are important are important Consider relationships in sketches as • Consider relationships in sketches as • query constraints query constraints Interpret sketch as “sentence” of a • Interpret sketch as “sentence” of a • visual query language visual query language Explicit Meta Information Relaxation of geometrical • Relaxation of geometrical • (topological) constraints needed (topological) constraints needed Derived constraints (e.g. centered) • Derived constraints (e.g. centered) • Vo lke r Haarslev, Se pte mbe r 97
Naive Physics Metaphor Semantics of Query Objects Physical properties visualize semantics Physical properties visualize semantics 0-D : marbles, nails, swivel joints • 0-D : marbles, nails, swivel joints • Vi vid e.g. marble: roll around, change position e.g. marble: roll around, change position 1-D : (cross) beams, rubber bands, telescop S patial • 1-D : (cross) beams, rubber bands, telescop • antenna antenna Co nstellations e.g. rubber band: stretch, shrink, wrap around e.g. rubber band: stretch, shrink, wrap around 2-D : enclosures, transparencies • 2-D : enclosures, transparencies • e.g. enclosure: fenced area trapping marbles e.g. enclosure: fenced area trapping marbles Animation Degrees of freedom gained by relaxations • Degrees of freedom gained by relaxations • Variations of user sketches visualized by • Variations of user sketches visualized by • animations animations Vo lke r Haarslev, Se pte mbe r 97
VISCO’s Language Elements Parallelogram Crossbeams as example Fixpoint Fixed Angle Marble Minimal Angle Nail Maximal Angle Beam Min + Max Angle (Atomic) Rubber Band Compass Enclosure Polygon Transparency Film Vo lke r Haarslev, Se pte mbe r 97
VISCO: Transparency Films Basic Building Block Transparency film (of an overhead projector) • Transparency film (of an overhead projector) • • Rectangular shape • Rectangular shape • Own local cartesian coordinate system • Own local cartesian coordinate system • Can be scaled, translated, rotated, and stacked up • Can be scaled, translated, rotated, and stacked up • Fixpoint (w.r.t. transformations) is required • Fixpoint (w.r.t. transformations) is required • Any nail (isolated or as vertex) on transparency • Any nail (isolated or as vertex) on transparency Users interactively draw VISCO's query • Users interactively draw VISCO's query • elements elements Collection of drawn elements defines • Collection of drawn elements defines • (sub)constellation One transparency • (sub)constellation One transparency • as drawing sheet • Geometrical and topological relationships are as drawing sheet • Geometrical and topological relationships are relevant Two transparencies • relevant Two transparencies • each with objects each with objects Vo lke r Haarslev, Se pte mbe r 97
Example: Various Quadrilaterals 4 matches at most 4 4 beams as edges 4 beams as edges • • • matches at most 4 4 beams as edges 4 beams as edges • • • line segments marbles act as marbles may float • • line segments marbles act as marbles may float • • marbles act as swivel joints and inside of enclosure • marbles act as swivel joints and inside of enclosure • swivel joints and may float inside of beams have a • swivel joints and may float inside of beams have a may float inside of enclosure • fixed length and a may float inside of enclosure fixed length and a enclosure beams have a fixed right angle • enclosure beams have a fixed right angle • rubber bands may fixed length • fixed orientation • rubber bands may fixed length • fixed orientation stretch or shrink • stretch or shrink Vo lke r Haarslev, Se pte mbe r 97
VISCO: Enclosures and Points Enclosure Point Enclosure is meta object Semantics of nails not affected • • Enclosure is meta object Semantics of nails not affected • • • visualized by a gray texture Marbles are only allowed inside • • visualized by a gray texture Marbles are only allowed inside • of enclosures • all enclosed objects are "trapped" and of enclosures • all enclosed objects are "trapped" and must stay inside of their enclosure Marbles may freely change their must stay inside of their enclosure • Marbles may freely change their • Two types of enclosures position • Two types of enclosures position • • translucent : also consider • translucent : also consider relationships with other visible objects relationships with other visible objects • opaque : hidden objects are excluded • opaque : hidden objects are excluded Computed ε -enclosures • Computed ε -enclosures • • interior or exterior (border) of an 4 • interior or exterior (border) of an object object • radius is required • radius is required Vo lke r Haarslev, Se pte mbe r 97
Example: Rectangle Touching Scalable Circle Vo lke r Haarslev, Se pte mbe r 97
City Map Example: Öjendorf as Subsection of Hamburg Areas intended as • Areas intended as • query matches are query matches are marked marked Input for query • Input for query • processing is a vector processing is a vector representation of this representation of this map map Map data donated by the 'Amt für Geoinformation und Vermessung' Vo lke r Haarslev, Se pte mbe r 97
City Map Example: Church in vicinity of subway station Snapshots of query construction with example of intended match Create transparency of fixed size • Create transparency of fixed size • 300m (300 x 300 m) (300 x 300 m) Draw a fixpoint (nail) and attach • Draw a fixpoint (nail) and attach • the concept 'SubwayStation' to 300m the concept 'SubwayStation' to fixpoint fixpoint • fixpoint may coincide with any • fixpoint may coincide with any point object in database point object in database Generate circular ε -enclosure 300m • 300m Generate circular ε -enclosure • • fixpoint as center • fixpoint as center SubwayStation SubwayStation • radius of 100 m 300m 300m • radius of 100 m Draw a marble inside of the • Church Draw a marble inside of the • enclosure and attach the concept enclosure and attach the concept 'Church' to marble 'Church' to marble Vo lke r Haarslev, Se pte mbe r 97
City Map Example: 3 adjacent buildings aligned in parallel (1) 4 Building 4 Building 4 Building Create scalable, rotatable Sketch three quadrilaterals Create scalable, rotatable Sketch three quadrilaterals transparency with enclosure transparency with enclosure Vo lke r Haarslev, Se pte mbe r 97
City Map Example: 3 adjacent buildings aligned in parallel (2) 4 4 Building Building 4 4 Building Building 4 4 Building Building Constrain orientation of edges Generate center points of Constrain orientation of edges Generate center points of as visualized quadrilaterals (marbles) as visualized quadrilaterals (marbles) Vo lke r Haarslev, Se pte mbe r 97
City Map Example: 3 adjacent buildings aligned in parallel (3) Example of intended match 4 Building 4 Building 4 Building Draw enclosure confining Draw enclosure confining center points more closely center points more closely Vo lke r Haarslev, Se pte mbe r 97
Conclusion and Ongoing Research VISCO is innovative compared to other relevant approaches • VISCO is innovative compared to other relevant approaches • (see related work in paper) (see related work in paper) • geometric as well as topological queries or combination of both • geometric as well as topological queries or combination of both • high expressiveness by interpreting topological relations as • high expressiveness by interpreting topological relations as qualitative constraints enriched with meta information qualitative constraints enriched with meta information • simple but powerful 'naive physics' metaphor • simple but powerful 'naive physics' metaphor • approximate or vague objects/constellations possible • approximate or vague objects/constellations possible Prototype implementation partially completed (user interface) • Prototype implementation partially completed (user interface) • Query semantics specified by translational semantics (typed • Query semantics specified by translational semantics (typed • lambda calculus) lambda calculus) Description logic framework for query processing and • Description logic framework for query processing and • optimization is under development optimization is under development Vo lke r Haarslev, Se pte mbe r 97
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