Cameras - Game Programming Algorithms and Techniques - page 205

ing an orbit camera using spherical coordinates, but I find the approach presented
here a bit easier to follow.

Listing 8.2 Orbit Camera

Click here to view code image

class OrbitCamera
// Up vector for camera
Vector3 up
// Offset from target
Vector3 offset
// Target object
GameObject target
// Final camera matrix
Matrix cameraMatrix

// Initializes the initial camera state
function Initialize( GameObject myTarget , Vector3
myOffset )
// In a y-up world, the up vector can just be
the Y axis
up = Vector3 (0,1,0)

offset = myOffset
target = myTarget

// CreateLookAt parameters are eye, target,

and up

cameraMatrix = CreateLookAt( target . position +
offset ,

target . position ,

up )

end

// Updates based on the incremental yaw/pitch
angles for this frame
function Update( float yaw , float pitch )