Computer Graphics as Virtual Photography -- A Tour June 10, 1999 - PowerPoint PPT Presentation

Computer Graphics as Virtual Photography -- A Tour June 10, 1999

Motivational Film ✔ Geri’s Game June 10, 1999

More thoughts on projects ✔ Implementation as a means to learn a system or language (VRML, Java3D, Renderman, RADIANCE). ✔ Animation -- focus on lighting, scenery, texture, rather than motion. ✔ Implement algorithm presented in paper. June 10, 1999

Example projects ✔ See Prof Nan Schaller’s page: – http://www.cs.rit.edu/~ncs/Courses/571.shtml ✔ Finding References – http://liinwww.ira.uka.de/bibliography/Graphics/ June 10, 1999

Just an aside... ✔ Dwarfs that got left on the cutting room floor: – Clumsy – Dummy – Sleezy – Ozzy – Cheesy – Moe, Curly – Token Joe June 10, 1999

What is this course about? ✔ In short: Creating images by mimicing photography. June 10, 1999

What is this course about? pho•tog•ra•phy, n ., the process or art of producing images of objects by the action of light on a sensitized surface, esp, a film in a camera. Photography = writing with light June 10, 1999

Process of Creating Images light Direct light Reflected light Viewing scene window Images are a view of the world from a given perspective June 10, 1999

Computer Graphics as Virtual Photography real camera photo Photographic Photography: scene (captures processing print light) processing camera Computer 3D synthetic tone model Graphics: models image reproduction (focuses simulated lighting) June 10, 1999

In this lecture ✔ Give an overview of the major topics of the course – Light – Modeling – Rendering – Camera Models – Tone Reproduction ✔ Introduction to papers on reserve June 10, 1999

Topic I - Light ✔ Photography, CG, and sight all have to do with simulating the response to light! ✔ Physically based approach to light and simulation June 10, 1999

Topic I : Light ✔ Nature of light (June 14th) – What it is? – How does it behave? – How is it measured? – How does it create color? ✔ Lighting Models (June 17th) – stage lighting – light scattering June 10, 1999

Topic I: Papers on light ✔ Ashdown -- overview of lighting units. ✔ Glassner -- deriving a spectrum from RGB values ✔ Marschner -- reversing the pipeline ✔ Greenberg -- image synthesis framework at Cornell. ✔ Dorsey -- modeling stage lighting ✔ Klassen -- modeling atmospheric effects ✔ Barzel - movie lighting (Toy Story) June 10, 1999

Computer Graphics as Virtual Photography real camera photo Photographic Photography: scene (captures processing print light) processing camera Computer 3D synthetic tone model Graphics: models image reproduction (focuses simulated lighting) June 10, 1999

Topic II - Modeling ✔ Describing a scene to a computer ✔ Shading – specifying how objects interact with light ✔ Solid Modeling – Object - describing individual objects – Scene - describing placement of objects, lights, and other elements in the entire scene June 10, 1999

Topic II : Modeling ✔ Shading (June 22nd) – Surface properties – Bidirectional reflection functions (BDRF) ✔ Shading Models (June 24th) – approximating BRDFs ✔ Shading Languages – Renderman June 10, 1999

Topic II - Modeling ✔ Object Modeling (June 29th) – shape – texture – procedural models ✔ Scene Modeling (July 1st) – coordinate spaces & transformation – graph representation - VRML & Java 3D June 10, 1999

Topic II: Modeling ✔ Special topics – Particle Systems / Modeling Lightning (July 15th) – VRML ( July 13th) June 10, 1999

Topic II: Papers on Modeling ✔ Shading – Cook/Torrance - Introduction of BRDFs – Blinn - simulating wrinkled surfaces – Dorsey - modeling surface wear and tear. – Cook - basis for Renderman shading langauge – Hanrahan -- Renderman shading lang. – Perlin -- procedural textures June 10, 1999

Topic II : Papers on Modeling ✔ Object Modeling – Perlin - procedural 3d models – Musgrave -- fractal landscapes – Fournier -- stochastic models ✔ Scene Modeling – Kilgard -- OpenGL – Strauss -- Inventor (precursor to VRML) – Koved -- Object oriented scene description June 10, 1999

Computer Graphics as Virtual Photography real camera photo Photographic Photography: scene (captures processing print light) processing camera Computer 3D synthetic tone model Graphics: models image reproduction (focuses simulated lighting) June 10, 1999

Topic III - Rendering ✔ Simulation of the transport of light within a scene. – Rendering Equation – Ray tracing – Radiosity – Combined methods – Other methods June 10, 1999

Topic III: Rendering ✔ Rendering Equation (July 6th) – Theoretical basis for all rendering methods. – Dense but VERY important June 10, 1999

Topic III: Rendering ✔ Ray Tracing (July 8th) – Following the recursive path of light as it goes from the scene to your eye – Distributed ray tracing June 10, 1999

Topic III: Rendering ✔ Radiosity (July 20th) – calculation of steady state energy transport. June 10, 1999

Topic III: Rendering ✔ Mixed Methods (July 22) – Ray tracing + radiosity ✔ Alternate methods – REYES – RADIANCE June 10, 1999

Topic III: Papers on Rendering ✔ Rendering Equation – Kajia - classic paper ✔ Ray Tracing – Whitted -- original ray tracing paper – Cook -- distributed ray tracing – Musgrave -- ray tracing mirages – Parker -- interactive ray tracing – Heckbert -- ray tracing JELLO (*) June 10, 1999

Topic III: Papers on Rendering ✔ Radiosity – Goral -- original radiosity paper – Cohen -- 1st radiosity solution – Wallace -- radiosity + ray tracing ✔ Other methods – Cook -- REYES – Ward -- RADIANCE – Gritz -- BMRT June 10, 1999

Computer Graphics as Virtual Photography real camera photo Photographic Photography: scene (captures processing print light) processing camera Computer 3D synthetic tone model Graphics: models image reproduction (focuses simulated lighting) June 10, 1999

Topic IV - Camera ✔ Focus the light from a scene on to a 2D plane. – Perspective transformation – Depth of field – Motion blur – optical simulation – light fields (Lumigraph) June 10, 1999

Topic IV : Camera Models ✔ Models from basic to sophisticated (July 27th) – Basic Pinhole Camera – Add depth of field and focus – Lens optics simulation ✔ Light field rendering (July 29th) – Rendering using a 4D light space June 10, 1999

Topic IV: Camera Papers ✔ Camera Models – Potmesil -- first realistic camera model – Kolb -- simulating lens optics – Heidrich -- using light fields ✔ Light field rendering – Gortler -- one of the original papers – Levoy -- the other original paper – Sloan -- fast calculations June 10, 1999

Computer Graphics as Virtual Photography real camera photo Photographic Photography: scene (captures processing print light) processing camera Computer 3D synthetic tone model Graphics: models image reproduction (focuses simulated lighting) June 10, 1999

Topic V - Tone Reproduction ✔ Response of light used in creating the final image. (Aug 3) – Human visual response – Photographic response ✔ Issues about output media (Aug 5) – Color management June 10, 1999

Topic V: Papers on Tone Reproduction ✔ Tone Reproduction – Tublin -- why it is a problem – Ferwerda -- human visual response – Geigel -- photographic response ✔ Color Management – Glassner -- Device directed rendering – Stone -- gamut mapping – Lindbloom -- accurate color reproduction June 10, 1999

Intermission ✔ Aug 10 - 12 SIGGRAPH – Looking for guest speakers – Extend classes during last week for more demos? June 10, 1999

Project Demos ✔ Aug 17th and Aug 20th June 10, 1999

That’s the course in a nutshell ✔ Any questions? June 10, 1999

For next time ✔ Keep thinking about your project…Proposals are due next Thursday ✔ Research paper reading begins with next lecture. June 10, 1999

Next Class ✔ Light – What it is – How it behaves – How we measure it – Light and color June 10, 1999

Remember ✔ Class Web Site: – http://www.cs.rit.edu/~jmg/virtualPhoto June 10, 1999