3-Dimensional Modeling Docent: Marc van Kreveld BBL-416 m.j.vankreveld@uu.nl
3-dimensional modeling • Blok 4, bachelor informatica, niveau 3 • GebondenkeuzevakGametechnologie • Discipline-gebondenkeuzevakInformatica • 7.5 ECTS = 220 uur • Gewijzigdt.o.v. eervorigjaar (inhoud & docent) • Colleges, geenwerkcolleges, welgrootpractikum • Voorkennis: graphics, datastructuren
3-dimensional modeling • Specifiekevoorkennis: • vectoren, matrices, transformaties • functies, polynomen, logaritmen, trigoniometrie • statistiek: stadaarddeviatie, regressie, … • algoritmiek: aanpak, efficiëntie • programmeren: C# / C++
3-dimensional modeling, practicum • Begeleidpractikum, altijdna college, in driegroepen, tegelijk (2 x 2 uur/week) • 3 opdrachten • Modelleren met Blender: hand en monster • Splines implementeren: Bezier en B-spline • RANSAC experimenteelonderzoekomvlakkentevinden • Stel het werknietuit tot de inleverdag! Die dag is het vaak extra druk in de practikumzalen en is de begeleidingookdrukker
3-dimensional modeling, practicum • Twee begeleiders • Frank Staals (groepen 1 en 2) • Maarten Löffler (groep3)
3-dimensional modeling, cijfers • Kleinetussentoets: 15% • Eindtentamen: 40% • Practischeopdrachten: 15% elk (3x) • Geenonderdeel met cijfer 4 of lager toegestaan • Eindtentamenminstenseen 5 • Gewogengemiddeldeafgerondeen 6 of hoger(dusonafgerondminstenseen 5.5) geslaagd
3-dimensional modeling, informatie • Informatie op de website • Feedback/vragen per e-mail naar de docent • Feedback/vragen over het practikumnaar je practikumbegeleider Frank of Maarten (nietnaarmij!) • Jouwtijd: • college: 14x2 uur, voor-/nastudie: 14x4 uur = 84 uur • practikum: begeleid 14x2 uur, zelfuitzoeken(installeren, leren, uitwerken) 14x4 uur = 84 uur • tentamen+voorbereiding: 20(?) uur Totaal: ongeveer 200 uur
3-dimensional modeling, materiaal • Verschillendebronnen • (er is geengeschiktboekvooralleonderwerpen) • Curves Graphics boek van Shirley & Marschner • Mesh representation deelszelfdeboek • Rest papers, surveys, wikipedia info • Alles: slides zelf
3-dimensional modeling, colleges • Er is geenwerkcollege, maar tijdens het college wordenwelopgavengemaakt (vaak de 10-15 minutenvóórde pauze of het eind) • sommetjes • begripvragen • discussievragen • Werk met je buurman/buurvrouw, zekervoor de discussievragen
3-dimensional modeling, schema • Let op het rooster dat on-line staat • Eersteweken: • 22 april: Introductie, nu • 24 april: Curves I en II (deels) • 29april: Curves II (deels) en III • 1mei: Curves IV • 6mei: Boundary models: mesh representatie, etc. • 8mei: Topological structuren, tetrahedralizaties, etc. stofvooreerstetoets
3-dimensional modeling, lecturer • is geen expert 3-dimensionaal modelleren • is geen expert implementeren, C#, Blender, … • is wel expert in algoritmen, meetkundigealgoritmen
3-dimensional modeling motivation and overview
3-dimensional modeling • Related to graphics, but not concerned with rendering, shading, textures, GPU, … • Instead, concerned with geometry, shape • As a research field, part of graphics and as an independent research field • SIGGRAPH conference • Symposium on Geometry Processing • Shape Modeling International
Some pictures
More pictures
Icons of 3D modeling Stanford bunny Utah teapot
Some Utah teapot images
Global 3D modeling pipeline data acquisition build model consistency check clean-up hand-drawn modeling consistency check use/render/ align with another model procedural modeling
Data acquisition methods • 3D scanning • consumer 3D scanners • coordinate measurement machines (CMM) • LiDAR scanning (airborne, ground-based) • CT scan, MRI scan • Stereo photography (SIFT points)
3D modeling software • Blender (free, open source) • Autodesk Maya • Autodesk 3DS Max (was: 3D Studio Max) • Cinema 4D • Google sketch-up • … for hand-generated models, often also procedural generation, rendering, animation, video generation, …
Procedural modeling • L-systems • Fractals
Main types of 3D models • Unstructured “models” • 3D point clouds • Boundary models • polygon meshes • curves and surfaces • implicit models • Solid models • constructive solid geometry (CSG) • voxel models
Quality in 3D modeling • Geometric quality: close to the desired model (in some distance measure) • Continuity, smoothness • Topological quality: the right holes and loops • Consistency: if triangle A stores triangle B as an adjacent triangle, then triangle Bshould store A as an adjacent triangle too
Efficiency in 3D modeling • 3D point clouds are large • to find the 10 nearest neighbors of each point, we do not want to scan the point set many times spatial search structures • 3D models consist of many elements (triangles) • to find the elements adjacent to a given element, we do not want to scan the whole model adjacency representation of model
Stanford bunny (1994) Maximum resolution of mesh: 69,451 triangles from 3D scanning
Happy buddha (1996, Stanford) Maximum resolution of mesh: 1,087,716 triangles from 3D scanning
ActueelHoogtebestand Nederland Airborne LiDAR scanning: ~ 135 x 109 height points (every 0.5x0.5 m), precision 5 cm (version AHN-2, 2012)
Reasons for 3D modeling • CAD/CAM, rapid prototyping, industrial design • Movie industry • Gaming industry (entertainment and serious) • Scientific (geology, hydrology, physics simulation) • Medical, surgery • Architecture, urban planning • Robotics • Monitoring
Reasons: CAM/CAM • Milling cutter • Use of molds • Stereo lithography
Reasons: movie industry • Futureworld (1976): first use of 3D wireframe animation • Pixar 1986 (1979) • Toy story (1995): first full-length, computer animatedmovie
Reasons: gaming • Entertainment • Serious, for training
Reasons: scientific • Geology, erosion • Water and air flow
Reasons: medical, surgery • Reconstruction from CT or MRI scans • Deformable tissue modeling • Dental models
Reasons: architecture
Reasons: robotics
Reasons: monitoring • Forest: growth/health • Coast, beach: sand loss
Main topics of the lectures • Curves, splines • Boundary representations • Implicit models • Triangular meshes and reconstruction • Urban reconstruction from point clouds • Efficiency and data structures • Procedural modeling
Other courses related to 3DM • Interaction technology (level 3) • Image processing (level 3) • Motion and manipulation (master GMT) • Multimedia modeling (master GMT) • Geometric algorithms (master GMT) • Multimodal interaction (master GMT) • Computer animation (master GMT)
Academic honesty Academic honesty is compulsory in accomplishing the assignment, projects, and the exams. Exchanging code with others is not allowed. Using code from the previous year or from the internet is prohibited, unless stated otherwise in the lectures. Copying texts of the reports from other groups is strictly prohibited. Generally, cheating, academic misconduct, plagiarism, and fabrication of output by other means than by your own implementation are not tolerated. We will use software to detect any code or text plagiarism. Any violation to the academic honesty will imply a fail to pass the course.
