E N D
Restitution and Interpretation of Spatial Representations A New Approach for Teaching RepresentationThierry Ciblac, Louis-Paul Untersteller, Pierre Macé ARIAM - LAREAEcole Nationale Supérieure d’Architecture de Paris la Villette - France[tciblac, lpu, pmace]@paris-lavillette.archi.freCAADe 2006
Restitution and Interpretation of Spatial Representations • Introduction • Case of restitution : polyhedron of « Melencolia I » of A. Dürer • Case of restitution when sketching : inclined skylight • Conclusion
Architects and spatial representations • Precise drawers? • Check and evaluate 3D representations • From 2D to 3D : • mental reconstruction of 3D objects : from 2D images • 3D restitution : 3D model from photographs, sketches in perspective… • What knowledge?
Theoretical tools for restitution Use of geometrical properties, not only drawing knowhow Properties : • Incidence properties in projective geometry • Parallelism, orthogonality properties in affine geometry • Metric properties in Euclidian geometry.
Case of restitution :polyhedron of « Melencolia I »of A. Dürer(1514)
Coherence of the 2D representation :Correction of the drawing • Hypothesis : Plane faces • Tools : Incidence properties. « 3 planes meet in one point » =B’3 E’’ E’’
Coherence of the 2D representation :Determination of hidden lines • Hypothesis : Plane faces but no hypothesis of parallelism. • Tools : Incidence properties, auxiliary planes.
Coherence of hidden lines :Comparison with a sketch of Dürer
Parallelism :Correction for parallel faces • Hypotheses : Plane faces, parallelism of opposite faces. magenta : parallelepiped orange : triangles in parallel planes • Tools : incidence properties, vanishing points (parallelism). pf1, pf1, pf3 : vanishing points of the direction of edges of a parallelepiped closed to the polyhedron
Parallelism :rebuilt polyhedron’s projection Comparison with the sketch : magenta : parallelepiped orange : triangles in parallel planes black : corrected sketch
Symetry and Orthogonality :principal point, principal distance • New Hypothesis : • equilateral triangles (give two couples of orthogonal directions)
3D RestitutionUsing « Photomodeler » Hypotheses : The principal point and principal distance are known. Symmetry of 120° according to a « vertical » axis. Initial position rotation of 120° rotation of 240°
Case of restitution when sketching :inclined skylightinspired by the Vitra museum of F. Ghery
Conclusion • Powerful theoretical tools • Implementation (Grassman Cayley algebra…) • Research : sketch restitution (Gina Project…) • Teaching these tools to architects…