CatenaryCAD: AnArchitecturalDesignTool TeamSixteen DanChak - PowerPoint PPT Presentation

CatenaryCAD:฀ An฀Architectural฀Design฀Tool Team฀Sixteen Dan฀Chak Megan฀Galbraith Axel฀Kilian 6.837฀Computer฀Graphics

Antonio฀Gaudi฀designed฀complex฀structures฀using฀ catenary฀systems

Beautiful฀forms฀were฀created฀by฀ suspending฀pieces฀of฀string฀from฀hooks, deforming฀them฀with฀weights฀and฀strings, then฀inverting฀the฀structural฀elements.

We฀created฀design฀ software฀for฀architects฀interested฀ in฀using฀catenary฀systems. CADenary฀

CADenary ฀is฀implemented฀using ฀ C++฀(physics฀modeling) ฀ OpenGL฀(graphics฀rendering) ฀ Tcl/Tk฀(user฀interface)

Goals฀We฀Met Interactive฀that฀runs฀in฀real-time Realistic-looking฀models฀of฀objects฀under฀gravity Hooks฀and฀strings฀placed฀in฀3D฀world Hooks฀accurately฀placed฀both฀in฀space฀and฀on฀strings Computed฀reasonable฀physics฀for฀the฀strings Can฀fmip฀designs฀180฀degrees฀to฀view฀as฀buildings Good฀software฀design Good฀design฀software

Goals฀We฀Did฀Not฀Meet Visualize฀external฀and฀internal฀forces฀on฀string฀particles Skins฀that฀render฀over฀the฀“wire฀frame”฀string฀structures Ability฀to฀save฀models฀for฀3D฀printing Implementing฀OpenNURBs

How฀We฀Approached฀the฀Project

cdObject cdParticle ry Geomet ion Physics฀Simulat a฀Model Dat cdParticleBucket cdParticleSystem a,b cdParticleEntry cdForceEntry cdForce cdSpring pos cdModel cdWeight cdString cdSkyHook cdStringHook cdHook a,฀b LineSegment Vect Program฀Data฀Model

Tcl/Tk฀User฀Interface฀ Create฀a฀new฀SkyHook Create฀a฀new฀StringHook Create฀a฀new฀String Select฀an฀object View฀the฀parameters฀of฀an฀object Spin฀the฀simulation฀180฀degrees Real-time฀graphics฀window Interactivity

Physics฀Simulation Spring-Particle฀System Chose฀Runge-Kutta฀solver฀(explicit) Produces฀reasonably฀robust฀solutions Susceptible฀to฀breaking฀with฀scale฀changes฀or฀ excessive฀stress Lack฀of฀conservation฀of฀length฀means฀a฀string฀ stretches฀1.5฀times฀the฀“at฀rest”฀length System฀unstable฀if฀stiffness฀parameter฀is฀set฀ beyond฀1

What฀We฀Learned How฀to฀code฀in฀an฀unfamiliar฀languages Challenges฀of฀rendering฀3D฀spaces฀and฀maintaining฀ believable฀interactions฀with฀objects฀in฀the฀space Important฀to฀choose฀appropriate฀solvers฀based฀on฀speed฀ requirements,฀robustness,฀and฀required฀precision฀of฀the฀ calculations Physics฀simulations฀can฀be฀tricky฀in฀3D Team฀(and฀code)฀management฀skills

What฀We฀Wish฀We฀Could฀Change C++฀may฀not฀have฀been฀the฀right฀choice...฀Java? Use฀one฀unifjed฀language฀for฀all฀aspects฀of฀the฀program Create฀the฀ability฀to฀develop฀the฀code฀on฀a฀variety฀of฀platforms฀ rather฀than฀only฀Linux

Individual฀Contributions Dan Setting฀up฀the฀development฀environment Writing฀the฀code฀that฀binds฀the฀C++฀classes฀with฀the฀UI Megan Building฀the฀user฀interface฀in฀Tcl/Tk Putting฀together฀the฀written฀report฀and฀presentation Axel Building฀the฀physics฀simulation/string฀models฀in฀C++

Deliverables CADenary฀program฀with฀basic฀features Java฀versions฀of฀the฀particle฀system Collection฀of฀short฀movies Source฀code Final฀Project฀Paper฀(.pdf) Final฀Presentation฀(.pdf)

CADenary

Java฀Tests

Short฀Movies 1฀ ฀ ฀ ฀ ฀ 2 3฀ ฀ ฀ ฀ ฀ 4

The฀End! ฀