CSCE 181 Guest Lecture 3
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CSCE 181 Reminders
Final report proposal due Thursday, March 3
1 page typed document
- name
- chosen topic
- initial list of at least 3 references
Short Report 3 - Put 1999 on the report somewhere for extra credit.
Jinxiang Chai: Computer Graphics
Different definitions from different individuals
- Visual Data: 3D models, images, videos, motion/animation
- Generation, storage and manipulation of visual data:
- Modeling
- Rendering
- Animation
- Image and Video processing
Evaluation can be easy (just ask anyone to look at what you've made)
3D Modeling
process of developing mathematical representation of 3D objects
- Polygon representation
- Using triangles to "approximate" the geometry of an object.
- The more triangles used, the smoother and more accurate the representation will be.
- Non-Uniform Rational B-Spline (NURBS) representations
- Smoothing objects into lines using localfunctions
- 3D Laser Scans (e.g. NextEngine)
- From images
- Similar to what Google SketchUp uses
An object's appearance depends on:
- material properties
- mirror, shiny, dull, matte/diffuse, transparent, translucent, refraction, etc.
- light is reflected back into the environment, scattered, and absorbed
- Texture
- colors and patterns on the object's surface
- Lighting
- types, number, locations, colors, properties
- Camera properties
- locations, orientation, focal length, perspective effect, etc.
Research:
- How can we represent all of these mathematically?
- How can we model these ideas quickly and easily?
Rendering
generation of images based on model's mathematical representations
Speed vs. Quality Tradeoff: People would like to generate a picture quickly, but quality decreases with faster speed. Graphic cards can speed up this process by delegating rendering tasks to a designated processor (GPU)
3D Animation
Creating moving objects based on rendered frames
Different properties generate different frames:
- fluid, flexible things (clothes), humans, animals, facial expressions
Animation Approaches:
- Animation software (requires a lot of talent and very time-consuming)
- Motion capture (most popular; uses real-world data)
- Physics equations (robotic, slow, and extremely complex equations
Image and video processing
- Warping - changing shape of image
- Image matting - changing background of an image
- Image Mosaics, Panorama, and Autostitching - Take many photos of the same thing into one big photo
- Cartoonification - Turning video/image into animated cartoon
- Digital Face beautification and Digital reshaping of human bodies - Promote vanity and obsession over appearance
Why Work on Computer Graphics?
- Fun!
- Solve important real-world problems
- Exciting applications
- Many job opportunities