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
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
import numpy as np
import yt
ds = yt.load("IsolatedGalaxy/galaxy0030/galaxy0030")
# We start by building a default volume rendering scene
im, sc = yt.volume_render(ds, field=("gas", "density"), fname="v0.png", sigma_clip=6.0)
sc.camera.set_width(ds.arr(0.1, "code_length"))
tf = sc.get_source().transfer_function
tf.clear()
tf.add_layers(
4, 0.01, col_bounds=[-27.5, -25.5], alpha=np.logspace(-3, 0, 4), colormap="RdBu_r"
)
sc.save("v1.png", sigma_clip=6.0)
# In this case, the default alphas used (np.logspace(-3,0,Nbins)) does not
# accentuate the outer regions of the galaxy. Let's start by bringing up the
# alpha values for each contour to go between 0.1 and 1.0
tf = sc.get_source().transfer_function
tf.clear()
tf.add_layers(
4, 0.01, col_bounds=[-27.5, -25.5], alpha=np.logspace(0, 0, 4), colormap="RdBu_r"
)
sc.save("v2.png", sigma_clip=6.0)
# Now let's set the grey_opacity to True. This should make the inner portions
# start to be obscured
tf.grey_opacity = True
sc.save("v3.png", sigma_clip=6.0)
# That looks pretty good, but let's start bumping up the opacity.
tf.clear()
tf.add_layers(
4,
0.01,
col_bounds=[-27.5, -25.5],
alpha=10.0 * np.ones(4, dtype="float64"),
colormap="RdBu_r",
)
sc.save("v4.png", sigma_clip=6.0)
# Let's bump up again to see if we can obscure the inner contour.
tf.clear()
tf.add_layers(
4,
0.01,
col_bounds=[-27.5, -25.5],
alpha=30.0 * np.ones(4, dtype="float64"),
colormap="RdBu_r",
)
sc.save("v5.png", sigma_clip=6.0)
# Now we are losing sight of everything. Let's see if we can obscure the next
# layer
tf.clear()
tf.add_layers(
4,
0.01,
col_bounds=[-27.5, -25.5],
alpha=100.0 * np.ones(4, dtype="float64"),
colormap="RdBu_r",
)
sc.save("v6.png", sigma_clip=6.0)
# That is very opaque! Now lets go back and see what it would look like with
# grey_opacity = False
tf.grey_opacity = False
sc.save("v7.png", sigma_clip=6.0)
# That looks pretty different, but the main thing is that you can see that the
# inner contours are somewhat visible again.
|
