Depth sorting

Question 1

What is Depth Sorting?

Answer 1

First draw the distant objects than the

closer objects. Pixels of each object overwrites the previous objects.

Question 2

Depth sorting is also known as

Answer 2

painters algorithm

Question 3

What is depth sort algorithm?

Answer 3

• Sort all the polygons based on their farthest z -coordinate
• Resolve ambiguities
• Draw the polygons in order from back to front

Question 4

what is the complexity of the depth sort algorithm?

Answer 4

This algorithm would be very simple if the z coordinates of the
polygons were guaranteed never to overlap. Unfortunately that is
usually not the case, which means that step 2 can be somewhat
complex

Question 5

When do ambiguities of two z extents arise?

Answer 5

Ambiguities arise when the Z extent of two surfaces overlap

Question 6

The test’s in Depth Sort Algorithm

if any of this does the test fails

Answer 6

Do P and Q x’s and y’s overlap
Is P entirely on the opposite side of Q’s plane from the viewport?
Is Q entirely on the same side P’s plane as the viewport?
Do the projections P and Q onto the (x,y) not overlap?

Question 7

What to do if all the tests fail?

Answer 7

Then reverse P and Q in the list of surfaces sorted by the maximum depth
Set a flag to say that the test has been performed
if the test fails a second time then it is necessary to split the surfaces and repeat the algorithm on the 4 new split surfaces