How to Tell if Object is No Longer in Camera View (bpy) I'm wondering what's the most efficient way to detect whether or not an object is entirely within the current camera's field of view. For example, if I'd want to allow variations in camera rotation until the object is at the edge of the field of view, so to speak.

Is there an easy way to do this?

Thanks!
Yes there's an easy way, go to the BGE Documentation to look for more information. Since you dont specified if you are using bpy or bge i go for bge.

from bge import logic
cont = logic.getCurrentController()
cam = cont.owner

# Test point [0.0, 0.0, 0.0]
if (cam.pointInsideFrustum([0.0, 0.0, 0.0])):
  # Point is inside frustum !
  # Do something useful !
else:
  # Box is outside the frustum !