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 ;; here's how motor-control/ proprioception will work: Each muscle is

    19 ;; defined by a 1-D array of numbers (the "motor pool") each of which

    20 ;; represent muscle fibers. A muscle also has a scalar :strength

    21 ;; factor which determines how strong the muscle as a whole is.

    22 ;; The effector function for a muscle takes a number < (count

    23 ;; motor-pool) and that number is said to "activate" all the muscle

    24 ;; fibers whose index is lower than the number.  Each fiber will apply

    25 ;; force in proportion to its value in the array.  Lower values cause

    26 ;; less force.  The lower values can be put at the "beginning" of the

    27 ;; 1-D array to simulate the layout of actual human muscles, which are

    28 ;; capable of more percise movements when exerting less force.

    29 

    30 (defn muscle-fiber-values

    31   "get motor pool strengths"

    32   [#^BufferedImage image]

    33   (vec

    34    (let [width (.getWidth image)]

    35      (for [x (range width)]

    36        (- 255

    37           (bit-and

    38            0x0000FF

    39            (.getRGB image x 0)))))))

    40 

    41 (defn creature-muscles 

    42  "Return the children of the creature's \"muscles\" node."

    43  [#^Node creature]

    44  (if-let [muscle-node (.getChild creature "muscles")]

    45    (seq (.getChildren muscle-node))

    46    (do (println-repl "could not find muscles node") [])))

    47 

    48 (defn single-muscle [#^Node parts #^Node muscle]

    49   (let [target (closest-node parts muscle)

    50         axis

    51         (.mult (.getWorldRotation muscle) Vector3f/UNIT_Y)

    52         strength (meta-data muscle "strength")

    53         image-name (read-string (meta-data muscle "muscle"))

    54         image 

    55         (ImageToAwt/convert

    56           (.getImage (.loadTexture (asset-manager) image-name))

    57           false false 0)

    58         fibers (muscle-fiber-values image)

    59         fiber-integral (reductions + fibers)

    60         force-index (vec

    61                      (map

    62                       #(float (* strength (/ % (last

    63                                                 fiber-integral))))

    64                       fiber-integral))

    65         control (.getControl target RigidBodyControl)]

    66     (fn [n]

    67       (let [pool-index (min n (count fibers))]

    68         (.applyTorque control (.mult axis (force-index n)))))))

    69 

    70 

    71 (defn enable-muscles

    72   "Must be called on a creature after RigidBodyControls have been

    73    created." 

    74   [#^Node creature]

    75   (let [muscles (creature-muscles creature)]

    76     (for [muscle muscles]

    77       (single-muscle creature muscle))))

    78 

    79 

    80 #+end_src

    81 

    82 

    83 

    84 

    85 

    86 * COMMENT code generation

    87 #+begin_src clojure :tangle ../src/cortex/movement.clj

    88 <<movement>>

    89 #+end_src
author	Robert McIntyre <rlm@mit.edu>
date	Sat, 04 Feb 2012 05:02:25 -0700
parents	2cbdd7034c6c
children	f1b078375484