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Wiki source code of Ball Physics

Version 5.1 by stu104225 on 2020/03/04 17:18
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stu104225 5.1 1 The **ball physics model** is meant to do things ... [TODO]
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stu104225 1.1 3 \\
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stu104225 5.1 7 {{toc/}}
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stu104225 4.1 9 == Ball trajectory ==
stu104225 1.1 10
stu104225 5.1 11 ----
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stu104225 4.1 13 The trajectory of a ball can be modeled to be parabolic.
stu104225 5.1 14 \\\\\\like so: .... [TODO]
stu104225 4.1 15
stu104225 1.1 16 == Configuration ==
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stu104225 5.1 18 ----
stu104225 1.1 19
stu104225 5.1 20 === Prediction parameters ===
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22 |=(((
23 Parameter
24 )))|=(((
25 Description
26 )))|=(((
27 Default value
28 )))
29 |(((
30 PREDICTION_FRAME
31 )))|(((
32 window size for prediction - How far
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34 into the future are predctions calculated at most.
35 )))|(((
36 70ms
37 )))
38 |(((
39 PREDICTION_STEP_SIZE
40 )))|(((
41 size of the steps for the forward search
42 )))|(((
43 10ms
44 )))
45 |(((
46 REFINEMENT_FACTOR
47 )))|(((
48 The prediction step size for the reverse search is
49 PREDICTION_STEP_SIZE divided by REFINEMENT_FACTOR.
50 )))|(((
51 10
52 )))
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54 with the default values up to 7 predictions are calculated if the ball is not predicted to be in flipper range roughly within the next two frames.
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56 \\
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58 So this number is also the worst case number of predictions calculated during the reverse search part of the prediction process.
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60 \\
61
62 === Flipper range ===
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stu104225 4.1 64 The model of the area, where the the flippers can hit a ball is computed from a set of five points. These points are set to real world coordinates in meter
stu104225 1.1 65
stu104225 4.1 66 and should not need further adjustment after the camera is correctly calibrated (see [[doc:World Coordinate System]]).
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stu104225 5.1 68 The values for the left flipper are set to be symmetrical.
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stu104225 1.1 70 [[image:attach:physics_points.png]]
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stu104225 5.1 72 (% class="wrapped" %)
stu104225 4.1 73 |=(((
74 Point#
75 )))|=(((
76 Description
77 )))
78 |(((
79 1
80 )))|(((
81 center point of the circle that the flippers tip moves o
82 )))
83 |(((
84 2
85 )))|(((
86 highest point a ball can be at when it hits the resting flipper
87 )))
88 |(((
89 3
90 )))|(((
91 lowest point a ball can be at when it hits the resting flipper
92 )))
93 |(((
94 4
95 )))|(((
96 lowest point a ball can be at when it hits the fully triggered flipper
97 )))
98 |(((
99 5
100 )))|(((
101 highest point a ball can be at when it hits the fully triggered flipper
102 )))
stu104225 1.1 103
104 \\
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stu104225 5.1 106 From these points an area, where the ball is deemed to be hittable, is computed.
stu104225 4.1 107
stu104225 1.1 108 [[image:attach:physics2.png]]
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110 \\
111
112 === Inlane Area ===
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stu104225 5.1 114 Since the trajectory prediction does not consider collisions in general, we need a different kind of predictions for the inlanes,
115 i.e. the path feeding a falling ball from the playfield to the flippers, behind the slingshot.
116 A ball is considered to be in an inlane, when it is in a rectangualar area, with one edge given by the begin of the flipper
117 and the other by a point at highest, outermost position of the angled part of the inlane.
stu104225 4.1 118
stu104225 1.1 119 [[image:attach:physics_inlane.png]]