Download presentation

Presentation is loading. Please wait.

Published byBrandon Hill Modified over 4 years ago

1
1GR2-00 GR2 Advanced Computer Graphics AGR Ken Brodlie kwb@scs.leeds.ac.uk Lecture 1 - Overview

2
2GR2-00 Objectives n To understand how 3D scenes can be modelled - in terms of geometry, appearance and behaviour - and rendered on a display n To understand how to deliver interactive animated 3D graphics over the Internet n To be able to create interactive 3D graphics applications using industry standard software (OpenGL and VRML)

3
3GR2-00 Lecture Outline - The Basics n MODELLING – representing objects in 3D – transforming objects and composing scenes n VIEWING – projecting 3D scenes onto a 2D display surface n RENDERING – illumination – shading – adding realism via textures, shadows

4
4GR2-00 Basic Modelling x y z objects represented as set of faces - ie polygons- and faces as a set of points scenes composed by scaling, rotating, translating objects to create a 3D world

5
5GR2-00 Viewing n Clipping – selects a volume of interest (cf 2D clipping in GR1) n Projection – 3D scene is projected onto a 2D plane camera

6
6GR2-00 Rendering ?? shading: how do we use our knowledge of illumination to shade surfaces in our world? illumination: how is light reflected from surfaces?

7
7GR2-00 Rendering n texture n shadows

8
8GR2-00 Lecture Outline - Internet n VRML – ISO standard for 3D graphics over the Web – allows modelling of geometry, appearance and behaviour

9
9GR2-00 Lecture Outline - Advanced n ADVANCED RENDERING – direct versus global illumination methods – ray tracing and radiosity n OTHER ADVANCED FEATURES – curve and surface modelling – image based rendering – non-photorealistic rendering

10
10GR2-00 Lecture Outline - Advanced n Advanced Rendering - global illumination – ray tracing – radiosity based on physics of radiative heat transfer between surfaces light eye screen objects

11
11GR2-00 Ray Tracing

12
12GR2-00 Radiosity

13
13GR2-00 Practical Outline n Basic graphics programming – creation of interactive 3D worlds using OpenGL n Web graphics – creating interactive, animated 3D virtual worlds on the Web using VRML n Practical work will use the Silicon Graphics O2 laboratory, and the linux machines

14
14GR2-00 AGR n Virtual Environments – study group looking at the advanced requirements for VR.. or interactive simulation n Practical work using Open Inventor

15
15GR2-00 Course Info n Lectures – Monday 2.00 - 3.00 (LT25) – Tuesday 1.00 - 2.00 (LT25) n Practicals n Web site – http://www.scs.leeds.ac.uk/kwb/GR2 n Newsgroups – local.modules.gr2local.modules.agr – local.modules.gr2.talklocal.modules.agr.talk

16
16GR2-00 Books n Computer Graphics (second edition) – Hearn and Baker, Prentice Hall n 3D Computer Graphics (third edition) – Alan Watt, Addison Wesley n Introduction to Computer Graphics – Foley, van Dam, Feiner and Hughes, Addison-Wesley

17
17GR2-00 Books n Interactive Computer Graphics (top- down approach using OpenGL) – Angel, Addison Wesley n The VRML 2.0 Handbook – Hartman and Wernecke, Addison-Wesley n OpenGL Manual

18
18GR2-00 Assessment ModuleExaminationCoursework GR275%25% AGR60%40%

19
19GR2-00 Before we begin...mathematics! n 3D Co-ordinate Systems LEFT RIGHT x y z x y z z points awayz points toward Align thumb with x, first finger with y, then second finger of appropriate hand gives z direction. Common now to use a RIGHT HANDED system.

20
20GR2-00 Points and Vectors n We shall write points as column vectors xyzxyz P = Difference of two points gives a direction vector: D = P 2 - P 1 x y z P2P2 P1P1 x y z P Note: If P1 and P2 are on a plane, then D lies in the plane

21
21GR2-00 Magnitude of a Vector n The magnitude of a vector V = (v 1,v 2,v 3 ) T is given by: |V| = sqrt(v 1 *v 1 + v 2 *v 2 + v 3 *v 3 ) eg (1,2,3) T has magnitude sqrt(14) n A unit vector has magnitude 1 n A unit vector in the direction of V is V / |V|

22
22GR2-00 Scalar or Dot Product n The scalar product, or dot product, of two vectors U and V is defined as: U.V = u 1 *v 1 + u 2 *v 2 + u 3 *v 3 n It is important in computer graphics because we can show that also: U.V = |U|*|V|*cos where is the angle between U and V This lets us calculate angle as cos = (u 1 *v 1 + u 2 *v 2 + u 3 *v 3 ) / (|U|*|V|)

23
23GR2-00 Diffuse Lighting n Diffuse reflection depends on angle between light direction and surface normal: reflected intensity = light intensity * cosine of angle between light direction and surface normal light normal scalar product lets us calculate cos

24
24GR2-00 Vector or Cross Product n The vector or cross product is defined as: UxV = (u 2 v 3 - u 3 v 2, u 3 v 1 - u 1 v 3, u 1 v 2 - u 2 v 1 ) n We can also show that: UxV = N |U||V| sin where N is unit vector orthogonal to U and V (forming a right handed system) and is angle between U and V n This allows us to find the normal to a plane – cross-product of two directions lying in plane, eg (P 3 -P 2 ), (P 2 -P 1 ), where P 1, P 2, P 3 are three points in the plane

Similar presentations

OK

1GR2-00 GR2 Advanced Computer Graphics AGR Lecture 17 Radiosity - Conclusion Non-PhotoRealistic Rendering.

1GR2-00 GR2 Advanced Computer Graphics AGR Lecture 17 Radiosity - Conclusion Non-PhotoRealistic Rendering.

© 2018 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google