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“A parametric approach towards the real-time interpretation of sketches in the early phases of architectural design”

Master thesis Jakob BeetzBauhaus - Universität Weimar

Dept. for computer science in architctureSupervised by Prof. Dr.-Ing. D. Donath andJun.Prof Dr.-Ing. F. Petzold

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Overview

– Architectural drawings– Related research– Parametric approach– Prototype– Discussion and future

works

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Drawings in Architecture: history

– Euclid: development of scientific geometry

– Vitruvius: architectura est scientia“

– Alberti: “lineamenta“ – “the texture of lines“

– Palladio: drawing becomes central medium of communication about arch.

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Common GUIs in architectural application

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Interface-technologies

– Sutherland: „Sketchpad“ lightpointer

– Doug Engelbart: Mouse

– Larry Roberts: „Lincoln Wand“ (Ultrasonic)

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Related research: Flatland

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Related research: Electronic Cocktail Napkin – M. Gross

1 2 3

6

98

54

7

3x3 grid:

Straight horiz. line: 4-5-6 (resp 6-5-4)Straight vert. line: 2-5-8 (resp 8-2-5)Box 1-2-3-6-9-8-7-4-1

Problem: Rotated strokes

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Related research: Quicksketch – Eggli, Bruederlin et al

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Approximation of splines through points

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Analysis of curvature

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Contour extraction: Winged Edge

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Recognition of features

Number of straight lines == 2 ?

true

fals

e

stroke

true

Symbol not recognized

Calc simplified strokescalc # of strokesCalc angle between strokesCalc length of strokes

true

min length <=

length of lines <=

max. length?

min angle <= angle between lines

<= max angle ?

Recognized symbol

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Information overlay: roomsizes

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Information overlay: emergency exits

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Information overlay: instant perspectives

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Prototype: software layers

WxWindows

native API of OS

OpenGL

OpenSceneGraphAIS (Open Cascade)

OS

Tab

let-D

aem

on

Application

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Prototype: data layoutDocument

1 .. n dots with pressure, timestamp etc.

strokes

Arch. elementsView on doc.

Tablet-Data

2D-view

3D-view

Overlay with add. info

Orig. sketch

Simplified geom.

sizelength

::

Interpretation in arch. context

Geom. analysis

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Prototype: Screenshot

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Future works:– Use of multi-agent

system?– Pattern language?– Pattern query by

expert system?– versioning-system

for sketches– Mobile use in site

measuring– Flexible plugin for

standard apps– Extension into 3rd

dimension

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Excursion: Software usedOpen Cascade:

Industry-scale CAD-API+ BRep– kernel+ Parametric

lines/surfaces (NURBS)+ Constraints-engine+ STEP and IGES

support+ Scripting engine+ C/C++ and Java-

bindings+ Linux/IRIX/Win32+ Open Source !!!- Somewhat sluggish

visualization

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Excursion: Software used

Mature scene-graph API+wrapper of complete set

of OpenGL, GLU, GLUT features

+ ever growing list of import/export filters (including 3DS Max files with Matlibs, Animations etc.)

+ particle engine+ excellent text-renderer+ LOD-mechanisms+ ShaderGL - support+ optimized for large

scenes+ Linux/IRIX/Win32+ Open Source !!!- only preliminary

tesselation and NURBS

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Excursion: Software usedOpenCV

+many useful implementations for image recognition (hugh transform, convex hull, contour extr. Etc.)

+fast data structures+loads of “near-

realtime” image filters+3d-reconstruction

from video streams+marker & feature

tracking+scripting extensions- heavy use of DirectX