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.

Wednesday, November 19, 2008

[Offtopic] Software Activation and IP Ownership

Softimage XSI has recently been acquired by Autodesk, the company that owns competing packages 3ds Max and Maya. Users who've purchased XSI through its former owner will now have to deal with Autodesk for any licensing and support issues.

Since XSI requires the software to be activated online before it can be used, existing users will be at Autodesk's mercy when reinstalling XSI onto their computers following catastrophic data loss or when transferring their license onto a new computer. These users, who purchased XSI with Softimage's particular activation policies in mind, will now be subject to Autodesk's activation policies and may even be required -- if Autodesk should so desire -- to agree to Autodesk's more restrictive licensing terms before Autodesk will agree to activate any copies of XSI purchased before the change of ownership.

Perhaps things will turn out okay for current XSI users, but there's no guarantee that will be the case. Whenever you use software that requires activation, you remain at the mercy of the software's copyright holder, which may change without warning and without any remedy to you, the user.