Add asteroid bands to sun exclusions in whole-system-asteroid fields

This adds exclusion bands around the sun’s exclusion zones of Bering, Omega-41, Tau-31 and Tau-23.
Those bands are using `cull_mode = 2` so only their sun-facing side is visible.
Also their fade distances was set up so they are mostly just visible when you are at the edge of the sun’s exclusion zones.
Same cull-mode and fade added for Tau-31 Harris exclusion band, too.

DATA/SOLAR/ASTEROIDS/bw08_rock_asteroid_field.ini

@@ -46,6 +46,19 @@ asteroid = nonmineable_asteroid30, -0.3, -0.3, 0.8, 72, 30, 185
 asteroid = nonmineable_asteroid90, -0.3, -0.3, -0.7, 103, 150, 43
 asteroid = nonmineable_asteroid30, -0.7, 0.4, -0.4, 81, 30, 60
 
+[ExclusionBand]
+zone = Zone_Bw08_sun_exclusion
+render_parts = 12
+shape = asteroid_belt_04
+height = 7000
+offset_dist = -500
+fade = 1, 1.35, 2, 3
+texture_aspect = 1
+color_shift = 1, 1, 1
+ambient_intensity = 5
+vert_increase = 2
+cull_mode = 2
+
 [AsteroidBillboards]
 count = 400
 start_dist = 2000

DATA/SOLAR/ASTEROIDS/bw10_ice_crystal_field.ini

@@ -60,18 +60,31 @@ exclude_billboards = 1
 exclusion = Zone_Bw10_path_img1_3
 exclude_billboards = 1
 
+[ExclusionBand]
+zone = Zone_Bw10_sun_exclusion
+render_parts = 12
+shape = asteroid_icebelt_04
+height = 7000
+offset_dist = -500
+fade = 1, 1.35, 4, 5
+texture_aspect = 1
+color_shift = 1, 1, 1
+ambient_intensity = 10
+vert_increase = 1
+cull_mode = 2
+
 [ExclusionBand]
 zone = Zone_Bw10_01_exclusion
 render_parts = 12
 shape = asteroid_icebelt_04
 height = 7000
 offset_dist = -500
-fade = 1, 1.35, 15, 17
+fade = 1, 1.35, 4, 6
 texture_aspect = 1
-color_shift = 0.8, 0.8, 1
+color_shift = 1, 1, 1
 ambient_intensity = 1.5
 vert_increase = 2
-cull_mode = 0
+cull_mode = 2
 
 [Cube]
 asteroid = ice_block_asteroid30, 0.6, 0.2, -0.2, 35, 10, 20

DATA/SOLAR/ASTEROIDS/ew03_planetary_fragments.ini

@@ -53,6 +53,19 @@ color_shift = 1, 1, 1
 ambient_intensity = 1
 size = 40, 110
 
+[ExclusionBand]
+zone = Zone_Ew03_sun_exclusion
+render_parts = 6
+shape = asteroid_belt_04
+height = 5000
+offset_dist = -500
+fade = 1, 1.2, 3, 4
+texture_aspect = 1
+color_shift = 4, 4, 4
+ambient_intensity = 1
+vert_increase = 2
+cull_mode = 2
+
 [DynamicAsteroids]
 asteroid = DAsteroid_planet_frag_small1
 count = 10

DATA/SOLAR/ASTEROIDS/iw01_tanner_rock_asteroid_field.ini

@@ -60,6 +60,19 @@ color_shift = 0.9, 0.9, 0.9
 ambient_intensity = 1.5
 size = 40, 100
 
+[ExclusionBand]
+zone = Zone_Iw01_sun_exclusion
+render_parts = 6
+shape = asteroid_belt_04
+height = 5000
+offset_dist = -500
+fade = 1, 1.25, 4.5, 6
+texture_aspect = 1
+color_shift = 4, 4, 4
+ambient_intensity = 1
+vert_increase = 2
+cull_mode = 2
+
 [DynamicAsteroids]
 asteroid = dasteroid_rock_small1
 count = 10