Convert BCF perspective camera to viewer camera state
BCF stores direction, but viewers need a look-at point. We compute target = position + direction * distance
Also converts from BCF's Z-up to viewer's Y-up coordinate system.
BCF perspective camera
Optional
Distance from eye to target (default: 10)
Convert BCF perspective camera to viewer camera state
BCF stores direction, but viewers need a look-at point. We compute target = position + direction * distance
Also converts from BCF's Z-up to viewer's Y-up coordinate system.