Ultimate Game Design : Building game worlds

Building Game Worlds
98
U L T I M A T E G A M E D E S I G N
Common Camera Problems
A host of problems can crop up with respect to your camera system—in fact, too
many to list them all here. Instead, I’ve chosen to focus on two major problem areas
for many camera systems.
The first problem is when the camera gets “stuck.” As you might imagine, when
you’re moving a camera or multiple cameras all around a scene, they can collide with
objects (and not know how to handle the collision). This creates a situation where a
camera gets stuck in a physical location in the scene or jumps away and freezes.
There can be several causes and several fixes for a stuck camera, but it is a common
problem worth mentioning. The best approach I can offer to avoid this problem is to
start by keeping your camera edits clean (well purposed and intentioned, don’t try
and do too much at once, allow your camera behavior to grow based on simple
script steps rather than try and get to the desired end-effect immediately). Also,
make sure that old and/or irrelevant camera position information is cleared out in
the camera control code.
The second common problem occurs when the camera’s view of game action is obscured
by something. In a third-person game, when the character is deep in the corner
of a walled or catacombed section of a level, they are often hidden from view. Some
games try to account for this by having the walls go transparent when a character is
obscured, enabling the player to see the character with X-ray ability.
Some players use this to their advantage by positioning their character in a corner
pocket deliberately, which causes the adjoining wall to turn transparent and gives
them a view of enemies waiting in the next room. This is a functionality trade-off you
may be forced to give the player, since the transparency region needs to cover a certain
scope or breadth to be effective in all possible cases where the camera is obstructed
by corners or pockets.
Other games, rather than build in an automatic transparency to the walls, make an
automatic camera move to get the character back into view in some fashion. Both of
these solutions can be difficult to build in, but can indeed provide a solution. Along
the way to creating a solution, these fixes can also create serious testing issues, since
every deep corner in your map has to be tested for either transparency compliance or
an auto camera repositioning, or for some measure of both.
It’s best to plan for these issues at game creation. It sounds simple, yet in the heat of
development, along with any number of other sizeable details, it can be duly identified
and ignored.
If you’re building a third-person game with enclosed or tight spaces, try to figure
out up front what camera problems you will likely encounter. Use this identification
process to influence the early building process. Assume that you may not have the
time or resources to be able to provide radical solutions if you make a bad move here.