1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
# This test case handles a specific task:
# to draw 2d objects in same scene with 3d objects while
# 2d objects need to be drawn in specific order on 3d plane and
# overlap correctly with 3d objects.
pload ALL
vinit
# Thin boxes represent overlapping 2d objects in same plane
# Normally such configuration would cause z-fighting noise (flickering)
box b1 -0.75 -0.75 0 1 1 0.01
box b2 -0.5 -0.5 0 1 1 0.01
box b3 -0.25 -0.25 0 1 1 0.01
vdisplay b1
vdisplay b2
vdisplay b3
vsetmaterial b2 silver
vsetmaterial b3 copper
psphere s 0.3
vdisplay s
# Create new z-layer for 3d objects
vzlayer add
vobjzlayer set s 1
vsetdispmode 1
# Disable OpenGl depth test for layer 0 (to eliminate flickering)
# But depth write is still enabled
vzlayer disable depthtest 0
# Disable depth buffer clearing for layer 1 (we want correct overlapping with 3d objects)
vzlayer disable depthclear 1
# List currently enabled settings of each layer
vzlayer settings 0
vzlayer settings 1
# "3d" box with one of its faces on same plane with "2d" objects
# Normally this also would cause flickering because new box is
# supposed to be in layer 1 as "3d" structure, thus depth test between
# new box and "2d" objects will be enabled.
box b 0 0 0.01 0.5 0.5 -0.5
vdisplay b
vobjzlayer set b 1
# To handle this situation, depth offset setting was introduced.
# It implemented with glPolygonOffset calls per layer.
vzlayer enable positiveoffset 1
vfit
|
