Querying GIS with Animated Spatial Sketches

Transcription

1 Querying GIS with Animated Spatial Sketches Volker Haarslev and Michael Wessel University of Hamburg, Germany Motivation VISCO's Language Elements Sketching Queries for City Map Examples Conclusion (Demo Slides)

2 Motivation Query Spatial Databases (GIS) Sketch constellation of spatial objects Sketch constellation of spatial objects Topological and geometric relationships Topological between and geometric components are relationships important between components 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)

3 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 e.g. marble: roll around, change position e.g. marble: roll around, change position 1-D: (cross) beams, rubber bands, telescop 1-D: (cross) beams, rubber bands, telescop antenna antenna 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 Vivid Spatial Constellations 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

4 VISCO s Language Elements Fixpoint Marble Nail Beam (Atomic) Rubber Band Crossbeams Fixed Angle Minimal Angle Maximal Angle Min + Max Angle Parallelogram as example Compass Enclosure Polygon Transparency Film

5 VISCO: Transparency Films Basic 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 (sub)constellation Geometrical and topological relationships are relevant Geometrical and topological relationships are relevant One transparency One transparency as drawing sheet as drawing sheet Two transparencies Two transparencies each with objects each with objects

6 Example: Various Quadrilaterals matches at most line matches segments at most line segments marbles act as swivel marbles joints act and as may swivel float joints inside and of enclosure may float inside of enclosure rubber bands may stretch rubber or bands shrink may stretch or shrink beams as edges beams as edges marbles act as swivel marbles joints act and as may swivel float joints inside and of enclosure may float inside of enclosure beams have a fixed beams length have a fixed length beams as edges beams as edges marbles may float inside marbles of enclosure may float inside of enclosure beams have a fixed beams length have and a a fixed fixed right length angle and a fixed right angle fixed orientation fixed orientation

7 VISCO: Enclosures and Points Enclosure Enclosure is meta object Enclosure is meta object visualized by a gray texture visualized by a gray texture all enclosed objects are "trapped" and must all enclosed stay inside objects of their are enclosure "trapped" and must stay inside of their enclosure Two types of enclosures Two types of enclosures translucent: also consider relationships translucent: with also other consider 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 object interior or exterior (border) of an object radius is required radius is required Point Semantics of nails not affected Semantics of nails not affected Marbles are only allowed inside Marbles are only allowed inside of enclosures of enclosures Marbles may freely change their Marbles may freely change their position position

8 Example: Rectangle Touching Scalable Circle

9

10 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'

11 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 (300 x 300 m) (300 x 300 m) Draw a fixpoint (nail) and attach Draw a fixpoint (nail) and attach the concept 'SubwayStation' to the concept 'SubwayStation' to fixpoint fixpoint fixpoint may coincide with any point fixpoint object may in coincide database with any point object in database Generate circular ε-enclosure Generate circular ε-enclosure fixpoint as center fixpoint as center radius of 100 m radius of 100 m Draw a marble inside of the Draw a marble inside of the enclosure and attach the concept enclosure and attach the concept 'Church' to marble 'Church' to marble 300m SubwayStation 300m 300m 300m SubwayStation Church 300m 300m

12 City Map Example: 3 adjacent buildings aligned in parallel (1) Create scalable, rotatable Create scalable, rotatable transparency with enclosure transparency with enclosure Sketch three quadrilaterals Sketch three quadrilaterals

13 City Map Example: 3 adjacent buildings aligned in parallel (2) Constrain orientation of edges Constrain orientation of edges as visualized as visualized Generate center points of Generate center points of quadrilaterals (marbles) quadrilaterals (marbles)

14 City Map Example: 3 adjacent buildings aligned in parallel (3) Example of intended match Draw enclosure confining Draw enclosure confining center points more closely center points more closely

15 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 qualitative high expressiveness constraints enriched by interpreting with meta topological information relations as 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