Games Development 2Review & Revision Strategy

CO3301

End of Semester 1

Today’s LectureToday’s Lecture

1. Exam Overview2. Exam Structure 3. Module Overview

– Entity IDs & communication, update & rendering– Resource Management– Data for Games / XML– Scripting for Games / Python– Tools for Games / C# – Concurrent Programming– Component-based Entities

4. Example Questions

Exam OverviewExam Overview

• Third year exams have a different focus than your 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 more 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

Exam StructureExam Structure

• Structure of this module’s exam:– Answer three questions out of four– Covering semester 1 material– Two hour exam + 10 minutes reading time

• Many questions are focused on comparisons between techniques– E.g. Compare use of entity pointers with UIDs– Case studies often used as basis for discussion

• Use notes and experience from labs / assignments to provide an intelligent discussion

• Will be a similar exam at the end of semester 2– On AI material

Topics: Entity IDs & Comms Topics: Entity IDs & Comms

• Need for and examples of entity identification• Identification alternatives:

– Entity pointers, named entities, entity UIDs– Usage of each of the above– Discussion of relative merits

• Implementing UIDs; Hash tables• Enitity interaction alternatives:

– Direct entity-entity class interaction• Use of member functions

– Messaging system; implementation issues– Pros and cons

Entity Update and Rendering Entity Update and Rendering

• Unique update function for each entity type– Contrast with single scene update function– Pros and cons

• Rendering functions, including pre- and post- rendering• Comparison with Model / Mesh approach

• Presented turning & movement work in week 2– Supports Gareth's material

• Method is examinable– With formulae

Resource ManagementResource Management

• Loading resources– At scene setup– Using setup script (c.f. XML)– Resources from templates– Streaming resources (large environments)

• Resource Manager– Dealing with shared resources / resource destruction

• Reference counting

– Late loading of resources

• Resource IDs– Kinds of resource

Text-based Game Data / XMLText-based Game Data / XML

• Hard-coded data– Examples– Limitations– Consider manual scene-setup & similar

• Rationale for using structured data language in games– Flexibility– Future-proofing

• Contrast between scripting and data languages• XML as a game data language

– Pros & cons, alternatives

Scripting for Games / Lua / Python Scripting for Games / Lua / Python

• Explanation of game scripting• Rationale

– Ease of use, iteration time, scripts as assets, flexibility

• Drawbacks– Performance– Clumsy interface code– Need for shared data between main code and script

• Consideration for use of scripting or not– Case studies

• Scripting languages• Lua / Python

– Key features– Simple programming

Component-based EntitiesComponent-based Entities

• Limitations of entity hierarchy / OO approach– Rigid hierarchy - inflexible– Tight coupling between parent & child etc.

• Component based alternative:– Components represent entity properties or abilities– Add / remove components dynamically– Entities become simple containers

• Pros & cons– Hierarchy much simplified– Great flexibility– Much more message passing– May be difficult to control precisely

Concurrent ProgrammingConcurrent Programming

• Explanation of concurrent programming– Distinction from parallel programming

• Processes & Threads– Difference

• Data / Resource Coordination– Example problem situations– ‘Race’ Conditions

• How to resolve

• Synchronisation techniques– Critical Sections, Mutexes, Semaphores– Timers, Events

• Deadlocks

Tools for GamesTools for Games

• Tools programming– Tool types and uses– Tool development

• Tool chains– Examples

• Increasing use of other high level languages (e.g. C#)– Rationale for use in games tools

Material not on ExamMaterial not on Exam

• The mathematical detail of camera picking will not be examined– An overview of the process involved may be required though

• Extensible factories will not be examined• The console development / middleware lecture will not be

covered

• Both Lua and Python may be covered– Especially comparative questions– However, any short scripts you are required to write will be in Lua

Example QuestionsExample Questions

• i) Evaluate three methods for entity identification

ii) What are the advantages and disadvantages of component-based entities

• i) Discuss the rationale for scripting in a large-scale commercial game

ii) Suggest a scenario when “.ini” files would be a justifiable alternative to XML files for text-based game data

• Further examples provided on past paper and worksheet