Introduction to E-Learning and the Three Cs of 3D Games - Creating E-Learning Games with Unity - page 14

change, we smooth out the current rotation and height more with a smaller
dampening value, and we tighten the interpolation with a larger value.
Also note that we multiply heightDamp by Time.deltaTime in order to
make the height interpolation frame rate independent, and instead depend-
ent on elapsed time, as follows:
RotAngle = Mathf.LerpAngle
(RotAngle, DesiredRotationAngle,
rotDamp);
Height = Mathf.Lerp
(Height, DesiredHeight, heightDamp *
Time.deltaTime);
10. The fourth and last step in our GameCam algorithm is to compute the position
of the camera.
Now that we have an interpolated rotation and height, we will place the cam-
era behind trackObject at the interpolated height and angle. To do this,
we will take the facing vector of trackObject and scale it by the negative
value of desiredDistance to find a vector pointing in the opposite direction
to trackObject ; doing this requires us to convert eulerAngles to Qua-
ternion to simplify the math (we can do it with one API function!).
Adding this to the trackObject position and setting the height gives the
desired offset behind the object, as shown in the following code:
Quaternion CurrentRotation =
Quaternion.Euler
(0.0f, RotAngle, 0.0f);
Vector3 pos =
trackObj.transform.position;
pos -=
CurrentRotation * Vector3.forward *
desiredDistance;
pos.y = Height;
transform.position = pos;