1. Discuss and types of object space methods in visible surface detection ?        
2. Discuss and types Image space methods in visible surface detection ?             

Learning Outcome:

Use program function to implement graphics primitives’ visibility detection.

all in fudamentals of computer graphics

Answer : When we view a picture containing non-transparent objects and surfaces, then we cannot see those objects from view which are behind from objects closer to eye. We must remove these hidden surfaces to get a realistic screen image. The identification and removal of these surfaces is called Hidden-surface problem.

There are two approaches for removing hidden surface problems − Object-Space method and Image-space method. The Object-space method is implemented in physical coordinate system and image-space method is implemented in screen coordinate system.

Answer (a) : Object space methods :

-> Back face detection.

-> Depth sorting method.

Answer (b) : Image space method :

-> Depth buffer method .

-> Scan line method.