Title: Visualisation, Animation and Virtual Reality
1Visualisation, Animation and Virtual Reality
- Lecture 8
- Intro to VR concepts
2Introduction
- Bob Hobbs
- K210
- r.g.hobbs_at_staffs.ac.uk
3Topics
- Lecture Content
- Week 8
- VR and Graphics concepts
- Week 9
- Tracking and interaction
- Week 10
- Collaboration, Immersion, Presence and Human
movement - Easter
- Weeks 11 12
- Assignment support
- Tutorial Content
- Week 8
- Desktop VR
- Week 9
- SGIs, Stereo, Sensors
- Week 10
- Implementing tracking using openGL in C
applications on SGIs - Easter
- Weeks 11 12
- Assignment Support
4Types of VR
- Augmented VR
- VR projected onto real life environment
- Desktop collaboration
- video image on screen
- computer tools - may be web-based
- video of room/work in progress
- see others work projected on your desk!
- Physical world/VR mixes
- Interaction between VR and external device
- Immersive VR
- helmet/goggles, CAVE
5Augmentation
6Phantom
7Phantom
Very common haptic device mainly used with
desktop systems to allow force feedback
8Business users
9VR headsets
- small TV screen for each eye
- slightly different angles
- 3D effect
10binocular/stereo vision
11Head-Mounted Displays
Head set field-of-view varies Software
configured to map to tracked environment
12Passive Stereo
Images projected simultaneously
13Anaglyphic Stereo
Like 3D stereo glasses
14Curved-Screen Systems
15TWR
16Curved-Screen Systems
17Cave
18(No Transcript)
19ImmersaDesk
(-3 3 0)
20VR Cave
21Me in the Cave
22Crumbs
- General viewing tool for regularly gridded 3D
scalar data in the CAVE. Developed to trace and
measure 1D fibers
23Crumbs Environment
24Color Map Adjustment
25Opacity Adjustment
26Spline Plane
27Structure of Vorticella convallaria
28How does VR work
- we live in a 3D world
- We have developed many methods to make sense of
the world around us - VR techniques have to try to recreate these
methods
29True VR involves the senses
- sight
- visual realism, 3D effects shadows, etc.,
- sound
- surround sound, sub-seat woofers etc.
- touch
- feedback from(and to) touch-sensitive gloves
302D v 3D
- Computer screen 2D
- Virtual environment 3D
- Map 3D to 2D
- Movement of objects is in 3 dimensional space
- High processing power
31What Makes a Picture 3-D?
- Requires many more lines and angles to produce 3D
- Must be able to define the lines and calculate
which are visible as viewpoint changes to show
motion - Colour, size and clarity of image indicate where
shape is in relation to viewer
32Steps to create a 3D scene
- Creating a virtual 3-D world by defining a
heirarchy of objects - Determining what part of the world will be shown
on the screen. - Determining how every pixel on the screen will
look so that the whole image appears as realistic
as possible.
33View the scene from one point
34Another view
35Inducing reality
- Define the shapes so that they can be seen in
motion 3D - Apply a surface texture
- Show perspective
- Lighting
- Blurring the edges
36A simple shape
Defined as a set of points or Vertices With
surfaces or facets defined by spline boundaries
created by joining points with lines
37More complex shapes
- Shape defined as polygons(triangles)
- Rounded surfaces created by more polygons
38Defining the surface
- Colour
- variation over surface
- Texture
- rough, smooth, etc
- Lighting
- creates shadowing
- Reflectance
- dependant on texture and colour
39Definition of Object
40Translation
Three degrees of Freedom in x, y, and z plane
41Six degrees of freedom
3 degrees of freedom correspond to the
rotational movement about each of the axes Pitch
Roll Yaw
42Scaling
Multiply one or more components of the line
vectors
43VRML file format
- filename (URL) ends ".wrl
- c.f. .html, .gif, .jpg etc.
- VRML 1.0 first line vrml 1.0 ascii
- VRML 2.0 first line vrml 2.0 utf8
- can have binary versions too
44contents of VRML file
- one or more nodes
- general format DEF object objecttype
fieldname value . . .
- or simply objecttype
fieldname value . . .
45sphere
VRML V1.0 ascii Sphere radius 1
46add colour
VRML V1.0 ascii Separator
groups things together Material
diffuseColor 1.0 0 0
red green blue Sphere radius
1
47a cone
VRML V1.0 ascii Separator Material
diffuseColor 0 0 1 bright blue
Cone height 3
48put them together ...
VRML V1.0 ascii Separator Separator
for sphere Texture2 filename
"big_alan.jpg" Sphere radius 1
Separator for cone Material
diffuseColor 0 0 1 bright blue
Cone height 3
49applications
- Simulation
- Learning
- Modeling Behavior
- Games
50Next Week
- Some more about geometry
- A little about graphics pipeline
- Viewport / Scene
- Depth Cues
- Tracking Systems
- Interaction with virtual environments