Wednesday, November 26, 2008

Moving Around in 2 and 3 Dimensions

Here are some differences between ground-level 3D and top-down 2D environments, and their implications for ease of navigation:
  1. The way the shapes of objects change as the player moves around the game environment. In 2D environments, rigid objects retain their projected shape as they change position and orientation due to player motion, while in 3D environments their apparent shape can change significantly.
  2. The way the angles between objects change as the player orbits around a particular point or travels along a path1, as measured from the camera's perspective. In 3D environments the apparent angles between objects are significantly affected as the player moves around, but remain fixed in 2D views.
For these reasons, a 2D view is generally more stable than a 3D view, as it doesn't change quite as radically as the 3D view when the player moves around the game world. Furthermore, since the view in top-down 2D games doesn't usually rotate as it does in 3D, a typical 2D view is remarkably stable compared to a 3D perspective. A stable view provides a more recognizable context than a more dynamic view, which makes it easier to tell where you are and which way to go.

1. If the player is moving along a straight line, angles between objects will change only if parallax is present.


Andrew said...

Neat, I'll add that knowledge to that of Soren's 2d vs. 3d piece:

I agree for the most part, although because the world itself is 3D, a well made 3D virtual world can be easy (but not as easy as a 2d world) to navigate given that it is consistent. You don't usually need direction arrows in 2d games though :) or if there are some, they're pretty easy to follow :D

Adrian Lopez said...

Hi Andrew,

One of my interests is to figure out ways to make 3D environments more navigable. I'm still working on it.