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refactored muscles
author Robert McIntyre <rlm@mit.edu>
date Fri, 03 Feb 2012 06:33:37 -0700
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children 2cbdd7034c6c
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157:84c67be00abe 158:811127d79d24
1 #+title: Movement!
2 #+author: Robert McIntyre
3 #+email: rlm@mit.edu
4 #+description: muscles for a simulated creature
5 #+keywords: simulation, jMonkeyEngine3, clojure
6 #+SETUPFILE: ../../aurellem/org/setup.org
7 #+INCLUDE: ../../aurellem/org/level-0.org
8
9 #+name: movement
10 #+begin_src clojure
11 (ns cortex.movement
12 (:use (cortex world util sense body))
13 (:import jme3tools.converters.ImageToAwt)
14 (:import java.awt.image.BufferedImage))
15
16 (cortex.import/mega-import-jme3)
17
18
19
20
21 ;; here's how motor-control/ proprioception will work: Each muscle is
22 ;; defined by a 1-D array of numbers (the "motor pool") each of which
23 ;; represent muscle fibers. A muscle also has a scalar :strength
24 ;; factor which determines how strong the muscle as a whole is.
25 ;; The effector function for a muscle takes a number < (count
26 ;; motor-pool) and that number is said to "activate" all the muscle
27 ;; fibers whose index is lower than the number. Each fiber will apply
28 ;; force in proportion to its value in the array. Lower values cause
29 ;; less force. The lower values can be put at the "beginning" of the
30 ;; 1-D array to simulate the layout of actual human muscles, which are
31 ;; capable of more percise movements when exerting less force.
32
33 ;; I don't know how to encode proprioception, so for now, just return
34 ;; a function for each joint that returns a triplet of floats which
35 ;; represent relative roll, pitch, and yaw. Write display code for
36 ;; this though.
37
38 (defn muscle-fiber-values
39 "get motor pool strengths"
40 [#^BufferedImage image]
41 (vec
42 (let [width (.getWidth image)]
43 (for [x (range width)]
44 (- 255
45 (bit-and
46 0x0000FF
47 (.getRGB image x 0)))))))
48
49
50 (defn creature-muscles
51 "Return the children of the creature's \"muscles\" node."
52 [#^Node creature]
53 (if-let [muscle-node (.getChild creature "muscles")]
54 (seq (.getChildren muscle-node))
55 (do (println-repl "could not find muscles node") [])))
56
57 (defn single-muscle [#^Node parts #^Node muscle]
58 (let [target (closest-node parts muscle)
59 axis
60 (.mult (.getWorldRotation muscle) Vector3f/UNIT_Y)
61 strength (meta-data muscle "strength")
62 image-name (read-string (meta-data muscle "muscle"))
63 image
64 (ImageToAwt/convert
65 (.getImage (.loadTexture (asset-manager) image-name))
66 false false 0)
67 fibers (muscle-fiber-values image)
68 fiber-integral (reductions + fibers)
69 force-index (vec
70 (map
71 #(float (* strength (/ % (last
72 fiber-integral))))
73 fiber-integral))
74 control (.getControl target RigidBodyControl)]
75 (fn [n]
76 (let [pool-index (min n (count fibers))]
77 (.applyTorque control (.mult axis (force-index n)))))))
78
79
80 (defn enable-muscles
81 "Must be called on a creature after RigidBodyControls have been
82 created."
83 [#^Node creature]
84 (let [muscles (creature-muscles creature)]
85 (for [muscle muscles]
86 (single-muscle creature muscle))))
87
88
89 #+end_src
90
91
92
93
94
95 * COMMENT code generation
96 #+begin_src clojure :tangle ../src/cortex/movement.clj
97 <<movement>>
98 #+end_src