Game Development Reference
In-Depth Information
Figure 17.3
A collision hull for a human character.
shape for sliding around objects or having objects slide around the character. Of
course, anytime the collision geometry doesn
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'
ll
see some anomalies. One of these is when a character
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s arm or leg pokes out of the
capsule
t match the visible geometry, you
this will show up in the game as characters sinking into walls and doors. If
the capsule is too large, the character might not fit through doorways or be able to
slip past other characters.
—
Crowded Games Require Smaller Collision Hulls
If you
s Left 4Dead, you probably recognize that the collision
hulls for the player characters and the zombies don
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ve played Valve
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t interact with each other
that much, or at least not so that you can tell. That
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s because there are so
many human characters running around that large collision hull
circumferences would cause you to get stuck behind your fellow AIs and
cause all manner of frustration. Also, if you notice the game environments,
there are not a lot of vertical objects like pipes or beams to get stuck on.
Make sure you take your game design into careful consideration when
designing the collision hulls, and that will influence the design of your game
environment.
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Just in case I wasn
t under physics control. It is a shape
that you move around yourself and check the physics system for collisions only when
you move it. How you move the hull is completely dependent on your game. You
could choose to allow the animation data to help you and minimize foot sliding. Or
you could find some flexibility by having a totally analog movement system tied right
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t clear, the character hull isn
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