Mercurial > cortex

     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
author	Robert McIntyre <rlm@mit.edu>
date	Fri, 03 Feb 2012 06:33:37 -0700
parents
children	2cbdd7034c6c