UGC NET CSE | December 2012 | Part 3 | Question: 33

Question

The Z-buffer algorithm is used for Hidden surface removal of objects. The maximum number of objects that can be handled by this algorithm shall

• A. depend on the application
• B. be arbitrary no. of objects
• C. depend on the memory availability
• D. depend on the processor

Answer 1

Ans is B 

In Z-buffer algorithm an arbitrary number of objects can be handled because each object is processed one at a time 

refer schaum series or https://issuu.com/imsf/docs/mcs-053/220

Answer 2

Depth Buffer (Z-Buffer) Method

1. An X x Y matrix is used to store all depth values of screen pixels.
2. Take one object. Store its z coordinate value to corresponding [pixel.
3. If another object also comes in same screen pixel, the pixel closer to observer will be saved. (z-culling)

Lets go through the options

• A. depend on the application : Z buffer algorithm will be same for any application. Not the answer
• B. be arbitrary no. of objects: as the number of objects heavily increases it will affect the performance. hence the answer
• C. depend on the memory availability: Only one matrix is needed to handle any number of objects. Wrong option
• D. depend on the processor: Not related with Z buffer algorithm, Wrong option

Answer is B