rlm@158: #+title: Movement!
rlm@158: #+author: Robert McIntyre
rlm@158: #+email: rlm@mit.edu
rlm@158: #+description: muscles for a simulated creature
rlm@158: #+keywords: simulation, jMonkeyEngine3, clojure
rlm@158: #+SETUPFILE: ../../aurellem/org/setup.org
rlm@158: #+INCLUDE: ../../aurellem/org/level-0.org
rlm@158: 
rlm@158: #+name: movement
rlm@158: #+begin_src clojure 
rlm@158: (ns cortex.movement
rlm@158:   (:use (cortex world util sense body))
rlm@158:   (:import jme3tools.converters.ImageToAwt)
rlm@158:   (:import java.awt.image.BufferedImage))
rlm@158: 
rlm@158: (cortex.import/mega-import-jme3)
rlm@158: 
rlm@158: 
rlm@158: 
rlm@158: 
rlm@158: ;; here's how motor-control/ proprioception will work: Each muscle is
rlm@158: ;; defined by a 1-D array of numbers (the "motor pool") each of which
rlm@158: ;; represent muscle fibers. A muscle also has a scalar :strength
rlm@158: ;; factor which determines how strong the muscle as a whole is.
rlm@158: ;; The effector function for a muscle takes a number < (count
rlm@158: ;; motor-pool) and that number is said to "activate" all the muscle
rlm@158: ;; fibers whose index is lower than the number.  Each fiber will apply
rlm@158: ;; force in proportion to its value in the array.  Lower values cause
rlm@158: ;; less force.  The lower values can be put at the "beginning" of the
rlm@158: ;; 1-D array to simulate the layout of actual human muscles, which are
rlm@158: ;; capable of more percise movements when exerting less force.
rlm@158: 
rlm@158: ;; I don't know how to encode proprioception, so for now, just return
rlm@158: ;; a function for each joint that returns a triplet of floats which
rlm@158: ;; represent relative roll, pitch, and yaw.  Write display code for
rlm@158: ;; this though.
rlm@158: 
rlm@158: (defn muscle-fiber-values
rlm@158:   "get motor pool strengths"
rlm@158:   [#^BufferedImage image]
rlm@158:   (vec
rlm@158:    (let [width (.getWidth image)]
rlm@158:      (for [x (range width)]
rlm@158:        (- 255
rlm@158:           (bit-and
rlm@158:            0x0000FF
rlm@158:            (.getRGB image x 0)))))))
rlm@158: 
rlm@158: 
rlm@158: (defn creature-muscles 
rlm@158:  "Return the children of the creature's \"muscles\" node."
rlm@158:  [#^Node creature]
rlm@158:  (if-let [muscle-node (.getChild creature "muscles")]
rlm@158:    (seq (.getChildren muscle-node))
rlm@158:    (do (println-repl "could not find muscles node") [])))
rlm@158: 
rlm@158: (defn single-muscle [#^Node parts #^Node muscle]
rlm@158:   (let [target (closest-node parts muscle)
rlm@158:         axis
rlm@158:         (.mult (.getWorldRotation muscle) Vector3f/UNIT_Y)
rlm@158:         strength (meta-data muscle "strength")
rlm@158:         image-name (read-string (meta-data muscle "muscle"))
rlm@158:         image 
rlm@158:         (ImageToAwt/convert
rlm@158:           (.getImage (.loadTexture (asset-manager) image-name))
rlm@158:           false false 0)
rlm@158:         fibers (muscle-fiber-values image)
rlm@158:         fiber-integral (reductions + fibers)
rlm@158:         force-index (vec
rlm@158:                      (map
rlm@158:                       #(float (* strength (/ % (last
rlm@158:                                                 fiber-integral))))
rlm@158:                       fiber-integral))
rlm@158:         control (.getControl target RigidBodyControl)]
rlm@158:     (fn [n]
rlm@158:       (let [pool-index (min n (count fibers))]
rlm@158:         (.applyTorque control (.mult axis (force-index n)))))))
rlm@158: 
rlm@158: 
rlm@158: (defn enable-muscles
rlm@158:   "Must be called on a creature after RigidBodyControls have been
rlm@158:    created." 
rlm@158:   [#^Node creature]
rlm@158:   (let [muscles (creature-muscles creature)]
rlm@158:     (for [muscle muscles]
rlm@158:       (single-muscle creature muscle))))
rlm@158: 
rlm@158: 
rlm@158: #+end_src
rlm@158: 
rlm@158: 
rlm@158: 
rlm@158: 
rlm@158: 
rlm@158: * COMMENT code generation
rlm@158: #+begin_src clojure :tangle ../src/cortex/movement.clj
rlm@158: <<movement>>
rlm@158: #+end_src