Fokus K3D 2010


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Fokus K3D 2010

  1. 1. The architectonic-style likelihood principle for procedural development of Cultural Heritage Virtual Worlds ELIOS Lab F. Bellotti , R. Berta, S. Cardona, A. De Gloria ELIOS Lab DIBE – University of Genoa
  2. 2. 3D urban areas <ul><li>3D reconstruction of a urban area for educational cultural Virtual Worlds (VWs) or Serious Games (SGs) </li></ul><ul><li>A trade-off between the 3D model’s realism and weight </li></ul><ul><ul><li>An impressive and culturally valid experience </li></ul></ul><ul><ul><ul><li>Photorealistic models, weather effects, surround-sound audio, graspable virtual objects, natural lighting system </li></ul></ul></ul><ul><ul><li>Performance and usability problems for an SG/VW online platform </li></ul></ul><ul><ul><ul><li>An enjoyable experience and real-time interactive exploration </li></ul></ul></ul>
  3. 3. 3D model details <ul><li>In a highly interactive system details are not fundamental </li></ul><ul><ul><li>However, in Cultural Heritage, the player is acting almost like an art detective. </li></ul></ul><ul><li>Highly realistic, complex systems are costly to implement </li></ul><ul><ul><li>3D modeling and texturing </li></ul></ul><ul><ul><ul><li>Taking and processing pictures (ground-level images) </li></ul></ul></ul>
  4. 4. Travel in Europe <ul><li>Involve students and teachers in living compelling adventures in a cultural SG </li></ul><ul><ul><li>Easy configuration through authoring tools </li></ul></ul><ul><ul><ul><li>Enhance the educational value also through content-creation </li></ul></ul></ul><ul><li>The artistic heritage domain involves strict requirements in terms of realism and cultural soundness </li></ul><ul><ul><li>Feeling the “sense of place” for a compelling and fruitful experience </li></ul></ul><ul><ul><li>A cognitive foundation </li></ul></ul><ul><ul><ul><li>After a visit, a visitor typically remembers the general features of a city, its architectonic styles. </li></ul></ul></ul>
  5. 5. Travel in Europe styles
  6. 6. The Architectonic Style Area algorithm <ul><li>Procedural generation of buildings for VWs/SGs based on the concept of “architectonic likelihood” </li></ul><ul><ul><li>Give players the sense of being in a particular city/area </li></ul></ul><ul><ul><ul><li>Not to implement a detailed reconstruction of every single building, but to single out few meaningful styles </li></ul></ul></ul><ul><ul><ul><ul><li>the templates out of which the single buildings can be instantiated through statistical variations </li></ul></ul></ul></ul><ul><ul><ul><li>An architecture ontology, a statistic description of the architectonic elements </li></ul></ul></ul><ul><ul><li>Outputs: facades for all the buildings in the area </li></ul></ul><ul><ul><li>Modeler responsibility shift </li></ul></ul><ul><ul><ul><li>From the 3D implementation and image texturing – to the definition of the architectural elements and their statistical description </li></ul></ul></ul>
  7. 7. Putting it all together <ul><li>Geo-referenced </li></ul><ul><ul><li>Ground elevated from a local 3D vectorial map </li></ul></ul><ul><ul><ul><li>Precise placement ensures compatibility/portability to GISs and expansibility of the system </li></ul></ul></ul><ul><li>Few Point-Of-Interests (POIs) </li></ul><ul><ul><li>Rigorous reconstruction at a high level of detail </li></ul></ul><ul><ul><li>Culturally meaningful buildings </li></ul></ul><ul><ul><ul><li>Cathedrals, theaters, and outstanding palaces. </li></ul></ul></ul><ul><li>Textures for other palaces built by the ASA, a statistical template-based algorithm </li></ul>
  8. 8. Related work <ul><li>A shape grammar with production rules that iteratively evolve a design by creating more and more details </li></ul><ul><ul><li>Our approach is not concerned on generating the 3D shape of the buildings, but focuses on the look of the façade exploiting architectural grammars </li></ul></ul>
  9. 9. Related works <ul><li>Mueller subdivide a facade texture in a top-down manner into elements such as floors, tiles, windows, and doors </li></ul><ul><ul><li>Image analysis to build semantic 3D models by detecting repetitions in the high-level facade structure </li></ul></ul><ul><li>Sketchaworld </li></ul><ul><ul><li>Procedural automatic reconstruction of environments based on semantics </li></ul></ul>
  10. 10. ASA approach <ul><li>A different point of view: </li></ul><ul><ul><li>identifying building templates in an area </li></ul></ul><ul><ul><li>focus on: </li></ul></ul><ul><ul><ul><li>facades rather than shapes </li></ul></ul></ul><ul><ul><ul><li>automation on the generation of instances by assembling components based on a statistical description </li></ul></ul></ul><ul><ul><li>Inline with educational aims of SG </li></ul></ul><ul><ul><ul><li>Empowerment of users for an easy generation of content </li></ul></ul></ul><ul><li>Not exploit semantics to build 3D models from images, but use architectural knowledge to prepare semantic rich 2D textures </li></ul>
  11. 11. ASA steps <ul><li>The Map: a 2D vectorial file (Autodesk AutoCAD 2004 DWG format) </li></ul><ul><li>3D generated by extruding the DWG polylines that represent the buildings </li></ul><ul><ul><li>Height, roof shapes and façades textures are determined and applied as results of the subsequent steps of the algorithm </li></ul></ul>
  12. 12. Definition of the building Templates (Styles) <ul><li>Define the building templates in the area </li></ul><ul><ul><li>E.g. various types of palaces, villas, churches with their frequency </li></ul></ul><ul><ul><li>The algorithm will instantiate buildings in the area out of these frequency values. </li></ul></ul><ul><ul><li>Example </li></ul></ul><ul><ul><ul><li>Glass Skyscrapers (20%) </li></ul></ul></ul><ul><ul><ul><li>Plaster Skyscrapers (30%) </li></ul></ul></ul><ul><ul><ul><li>Churches (5%) </li></ul></ul></ul><ul><ul><ul><li>Local Style A houses (15%) </li></ul></ul></ul><ul><ul><ul><li>Local Style B houses (30%) </li></ul></ul></ul>
  13. 13. Characterization of each template <ul><li>Constructs the texture for the façades of the buildings by exploiting architectural knowledge assembling architectonical elements </li></ul><ul><ul><li>windows, portals, shops, moulding storey, frieze, baseboard, etc </li></ul></ul><ul><ul><li>The modeler provides for each floor probabilistic data about elements distribution and textures for each elements </li></ul></ul><ul><ul><li>Higher level parameters include the height of the building, the number of floors, the type of roofs, etc. </li></ul></ul>
  14. 14. Parameters’ categories <ul><li>Vertical structure </li></ul><ul><ul><li>Number and height of floor types </li></ul></ul><ul><ul><ul><li>Ground, first, under roof, other floors </li></ul></ul></ul><ul><li>Ground floor </li></ul><ul><ul><li>Type and relevant density of shops, windows and doors </li></ul></ul><ul><li>Other floors </li></ul><ul><ul><li>Type and relevant density of windows, balconies, arches, quoins, plaster. Different statistics for the different types of floors: first, under roof and others. </li></ul></ul><ul><li>Roof </li></ul><ul><ul><li>Height, ridge, gutter, mansard, etc. </li></ul></ul>
  15. 15. Example
  16. 16. Parameters’ values <ul><li>For each parameter, the modeler specifies its possible values with the relevant frequency. Frequencies sum up to 1. </li></ul><ul><li>The relevant ortho-rectified pictures are to be provided for each value of each item (e.g. type of windows, balconies, etc.) in order for the algorithm to assembly instances of facades based on the statistical description of the architectonic components. </li></ul>
  17. 17. Architectonic parameters
  18. 18. Development tools <ul><li>The ASA Builder tool is the visual editing tool that implements the ASA algorithm for procedural construction of 3D models </li></ul>
  19. 19. Development tools <ul><li>A tool chain </li></ul><ul><ul><li>1- Template Creator </li></ul></ul><ul><ul><ul><li>Provide pictures and frequencies for each architectonic feature </li></ul></ul></ul><ul><ul><ul><li>Output: an XML file with all these data </li></ul></ul></ul><ul><ul><li>2- Façade Builder </li></ul></ul><ul><ul><ul><li>Generates the 3D models for all the buildings in the ASA area. Every building is textured with a texture synthetically generated on the basis of the Template Creator statistical description </li></ul></ul></ul>
  20. 20. Genoa
  21. 21. Strasbourg
  22. 22. Resources <ul><li> </li></ul><ul><li>[email_address] </li></ul>