Flash - 3D Engine design

I am going to redesign my 3D engine from the ground up. Now that I have some idea about how to do the coding, I need to make sure that I have the most efficient structure. Especially for Flash.

This is the process that I will take.

• Requirements Doc
• Use Cases
• Assign Responsibilities - Drawing lines and pictures
• Class Diagram
• CRC cards - Class Descriptions
• Interaction Diagrams
• Algorithms
• Test first coding
• Re-iterate

Requirements Doc

1. Import .obj Models
   - Vertices, faces, normals, colours, materials
   - Extensibility - can later add animation data, other formats - .3ds, .mdl
2. Data Structure
   - Linked Lists - see Watt 3d book appendix
   - Octrees
   - BSP
3. Rotation and Translation - x y z
4. Terrain Generation
   - Sinusoidal
   - Fractal
   - Other , heightmaps ?
5. Optimise Heavily
   - Single animation loop - all rendering and calcs
   - Precalculate as much as possible
6. Bounding Boxes - AABB
7. Collision Detection
   - but how to detect collision with terrain
8. Frustum Culling
9. BackFace Culling
10. Occlusion Culling
11. Camera
12. Lighting
    - Omnidirectional + ambient + inverse proportional distance
13. Shading
    - Flat
    - Gouraud
    - Textures
14. Project to 2D
15. Render/Draw to Screen

Use Cases

Import Model Data
Assign the Vertices to a pointsList Data Structure , assign Faces to a faceList, normals, colours

Create Models
From the data, create the model object and assign the data to object class variables.

Rotate Model x y z

Translate Model x y z

Import Terrain Data
Have the ability to parse terrain data from external sources

Create Terrain
Assign data to terrain class object variables

Place Terrain in World
set position and relation to the engine world system

Place Models in World
Position static and moveable objects in initial positions

Define Moveable and static Object Types
Moving Objects - planes, tanks, cars, spaceships
Static Objects - Terrain, Buildings , trees, Fortress that fires at you(eg)

Create Camera

Set Camera to follow Object

Change Camera settings
POV, follow another object

Light any/all Objects

Shade objects

Create Bounding Boxes - Detect Collisions

Perform Backface Culling

Occlusion Culling

Convert to 2D Coordinates

Draw/Render to screen

Z-Sort Objects
Flash - use swapDepths
Get average Z for face - Z sort routine

Class Definitions and Responsibilities

This is where I have done a first pass at working out what classes I will need and what responsibilities each class will have. It is not a final list, just something to get the mind working and starting to set some sort of platform. So here goes:

Class Descriptions

Now i will assemble all the member variables and methods of each class and determine method arguments and return types. Again, its a work in progress. You dont need to get it perfect. It is a process you work throught that helps you organise your ideas, thoughts and structures.

Vector3D Class

Matrix Class

Face Class

Light Class

Mesh Class

Terrain Class