Emerging Technologies for Games Review

1
Emerging Technologies for GamesReview Revision
Strategy

• CO3303
• Week 23

2
Todays Lecture

• Exam Overview
• Exam Structure
• Module Overview
• Quaternions / Animation
• Optimisation
• Spatial Partitioning
• Post processing
• Capabilities Effects
• Batching Instancing
• Concurrent Programming
• Example Questions

3
Exam Overview

• Third year exams have a different focus than
  second year exams
• 2nd year Explain process X Describe concept Y
• 3rd year, some of the above, but also Evaluate
  process X for use in situation Y Compare
  techniques A B
• Some marks for explaining module content
• But many marks for being able to evaluate what
  you have learnt
• Discussing topics rather than repeating them
• Applies to a greater or lesser extent to all exams

4
Exam Structure

• Structure of this modules exam
• Answer four questions out of five
• 25 each question
• Three hour exam 10 minutes reading time
• Some questions have many parts
• Six or more
• May require some lengthy answers
• Questions with few parts require considerable
  depth of discussion
• In any case, each mark is awarded for making a
  distinct point
• Rarely useful to repeat yourself

5
Topics Quaternions / Animation

• Comparison of methods to store rotations
• Euler angles, Matrices, Angle-axis form
  Quaternions
• Form of a quaternion with formulae
• Using quaternions (formulae in grey)
• Conversions, addition scaling
• Combining quaternions, rotating vectors
• Linear interpolation of transforms
• Position / scaling problems with rotation

6
Quaternions / Animation 2

• Normalised linear interpolation (nlerp)
• Spherical linear interpolation (slerp)
• Discussion of basic and derived formulae
• Animation
• Storage issues
• Transformation decomposition
• Keyframes
• Use of interpolation for in-between frames
• Multiway blending
• Bone masks
• Motion extraction

7
Optimisation

• Rationale for optimisation in games
• How and when to apply optimisation
• And when not to optimise
• Types of optimisation
• Speed, memory, bandwidth etc
• Optimisation techniques
• Loop unrolling, removing constant calculations
  etc.
• Applied techniques - may be given code to
  optimise
• Data structure and algorithm choice
• Memory cache use
• No shader optimisation in exams this year

8
Spatial Partitioning

• Rationale and uses for partitioning
• PVS for general partition schemes
• Generation, use limitations
• Portal based partitions
• Usage, refinements, pros cons
• BSP trees
• Construction, point location, use, pros cons
• Quadtrees / Octrees
• Creation, location, usage, loose quadtrees
• Diagrams common in partitioning questions

9
Post processing

• Front / back buffer usage, swap chains, VSync
• Render targets, post-processing, multiple render
  passes
• Post processing techniques
• Colour filters, blur, bloom, distortion, depth of
  field, feedback
• Explanation of algorithms used for the above
• Diagrams commonly expected in this topic

10
Capabilities Effects

• Render device capabilities
• Need for caps comparison of PC console
  situation situation with DirectX10
• Rendering in multiple passes
• Issues with inadequate capabilities
• Use of techniques / effects (fx files)

11
Batching Instancing

• State changes impact on render performance
• Improving rendering process wrt state changes
• Batch size impact on render performance
• Examples
• Instancing
• As a technique to render multiple models
• As a method to reduce batch sizes state changes
• Usage basic and advanced techniques

12
Concurrent Programming

• Explanation of concurrent programming
• Comparison with parallel programming
• Processes Threads Comparison
• Data / Resource Coordination
• Problem situations
• Race Conditions
• Synchronisation techniques
• Critical Sections, Mutexes, Semaphores
• Timers, Events
• Deadlocks

13
Material not on Exam

• Material from weeks 1, 2 8 is outside the scope
  of the module and wont be on the exam
• Project Essentials / Year 2 Additions
• Camera Picking
• Provided as support material
• Some recent material will not feature either
• Production processes / source control
• XNA development

14
Example Questions

• i) Explain how full-screen post-processing
  effects are performed in general. Illustrate your
  answer with a diagram
• ii) Describe a process to produce a depth of
  field effect using post-processing
• i) Explain the terms lerp, nlerp and slerp.
  Provide the formulae relevant to your answer.
• ii) Discuss the advantages and disadvantages of
  nlerp slerp for animation of rotations
• Further examples provided on past paper and
  worksheet