Game Development Reference
In-Depth Information
Ray Casting and Filters
Collision detection is a powerful tool to calculate hits and the intersection of two
or more objects in a game scene but not sufficient for most cases where we need to
predict collision before it actually happens. This chapter will unveil a very powerful
concept in game development called
ray casting
, to cover cases that cannot be
handled by collision detection. We will use ray casting to implement another very
interesting technique called
picking
, which is used by CAD software. Picking is
useful for many interactive use cases, where we need to map a mouse click by the
user (2D screen coordinates) to the local/world space of the objects in the scene.
Framebuffers is another very powerful concept used in game development. It has
many useful use cases from the implementation of view caching to implementations
of filters. We will cover the following topics in this chapter:
• Basic concepts of ray casting
• The basics of picking
• Implementing picking using ray casting
• Framebuffers
• Implementing filters using framebuffers
