Virtual World Note: Week 3

Steps to build a level

- paper design (level design document)

- asset creation

- layout

- scripting

- testing and tuning

Tool:

Maya (or 3D editor of choice)

Illustrator/ Flash/ Photoshop (or 2D editor, ...)

In-Engine Editors (UDK, Hammer, etc)

- Pipeline - all three

Building methods:

- free form --> good

     - (positive) good custom, good art quality, scale

     - (negative) resource intensive, hard to iterate, memory hog

- modular --> fast

     - (positive) flexible, iterative, re-usable

     - (bad) repetitive, restrictive

- procedural --> cheap

     - (positive) infinite world with one algorithm, replay value, less design time, technically efficient

     - (bad) not customizable/ predictable, near to impossible to pace, difficult to write, unrealistic/unnatural

Modular: landmarks, breadcrumbs

Most companies use free form and modular --> mix of two

Transition: going from one section (loaded chunk of world) to another

- hard loading --> cheap, easy to build but player to stop and wait for the loading -> led to stress in gaming especially when happens a lot of time

- portals --> do it in the game as you play

- streaming --> generous side of portals. As get closer, loads in and as get far throw away. In theory, allows player to see things available but never having useless stuff in memory. However, this is really hard to deal in engineer side.

Limitations:

- object count

     - memory

     - processing speed

Combat it with: instancing (same object and place it several times in scene --> only load it once), streaming (show only the ones close enough)

- draw calls (the number of time you tell the video card to put an object in screen, number of things can be drawn on screen)

Combat it with: culling, occlusion, LOD on shaders, batch rendering (draw similar thing that doesn't move in one batch for example draw a forest as a whole than individual tress)

PS: Unity does dynamic batching in Pro version

- view distance (far objects cannot be seen because it is being culled)

Combat it with: LOD, dynamic LOD

- light count

Combat it with: light mapping, deferred lighting (small light, big light tends to slow it down), plan where to put the light

Light is important in game as player tends to go to lightened up place. Player tends to feel more in better lighted place. It can be very big in setting specific mood.

- collision limitations

Combat it with: shell and wedges. Problem with this solution: invisible wall (wedges), floating (shell)

In 2D:

- scan line, historically (put objects in single scan line especially in old console)

- fill rate: the rate of drawing a pixel. In 2D, to create a depth feeling parallax is often used. These parallax cause a pixel is drawn several times