adding in crease stiffness

index.html

@@ -65,7 +65,7 @@
 
     <script id="zeroTexture" type="x-shader/x-fragment">
         void main(){
-            gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0);
+            gl_FragColor = vec4(0.0);
         }
     </script>
 
@@ -83,7 +83,7 @@
 
             float isFixed = texture2D(u_mass, scaledFragCoord).y;
             if (isFixed == 1.0){
-                gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0);
+                gl_FragColor = vec4(0.0);
                 return;
             }
 
@@ -113,7 +113,7 @@
 
             vec2 mass = texture2D(u_mass, scaledFragCoord).xy;
             if (mass.y == 1.0){
-                gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0);
+                gl_FragColor = vec4(0.0);
                 return;
             }
             vec3 force = texture2D(u_externalForces, scaledFragCoord).xyz;
@@ -153,6 +153,42 @@
         }
     </script>
 
+    <script id="thetaCalcShader" type="x-shader/x-fragment">
+        precision mediump float;
+        uniform vec2 u_textureDimFaces;
+        uniform vec2 u_textureDimCreases;
+        uniform sampler2D u_normals;
+        uniform sampler2D u_lastTheta;
+        uniform sampler2D u_creaseVectors;
+
+        void main(){
+
+            vec2 fragCoord = gl_FragCoord.xy;
+            vec2 scaledFragCoord = fragCoord/u_textureDimCreases;
+
+            vec4 lastTheta = texture2D(u_lastTheta, scaledFragCoord);
+
+            if (lastTheta[2]<0.0){
+                gl_FragColor = vec4(0.0, 0.0, -1.0, -1.0);
+                return;
+            }
+
+            vec2 normal1Index = vec2(mod(lastTheta[2], u_textureDimFaces.x)+0.5, floor(lastTheta[2]/u_textureDimFaces.x)+0.5);
+            normal1Index /= u_textureDimFaces;
+            vec2 normal2Index = vec2(mod(lastTheta[3], u_textureDimFaces.x)+0.5, floor(lastTheta[3]/u_textureDimFaces.x)+0.5);
+            normal2Index /= u_textureDimFaces;
+
+            vec3 normal1 = texture2D(u_normals, normal1Index).xyz;
+            vec3 normal2 = texture2D(u_normals, normal2Index).xyz;
+
+            float theta = acos(dot(normal1, normal2));//normals are already normalized, no need to divide by length
+            vec3 creaseVector = texture2D(u_creaseVectors, scaledFragCoord).xyz;
+            float sign = dot(cross(normal1, normal2), creaseVector);
+            if (sign < 0.0) theta *= -1.0;
+            gl_FragColor = vec4(theta, theta-lastTheta[0], lastTheta[2], lastTheta[3]);//[theta, w, normal1Index, normal2Index]
+        }
+    </script>
+
     <script type="text/javascript" src="dependencies/jquery-3.1.1.min.js"></script>
     <script type="text/javascript" src="dependencies/jquery-ui.min.js"></script>
     <script type="text/javascript" src="dependencies/flat-ui.min.js"></script>
@@ -169,6 +205,7 @@
     <script type="text/javascript" src="js/globals.js"></script>
     <script type="text/javascript" src="js/node.js"></script>
     <script type="text/javascript" src="js/beam.js"></script>
+    <script type="text/javascript" src="js/crease.js"></script>
     <script type="text/javascript" src="js/model.js"></script>
     <script type="text/javascript" src="js/dynamicModel.js"></script>
 
@@ -214,6 +251,12 @@
 </div>
 <div id="controls">
     <a href="#" id="about" class="btn btn-lg btn-default">About</a><br/><br/>
+
+    <div class="sliderInput" id="creaseAngle">
+        <span class="label-slider">Crease Angle : </span><div class="flat-slider ui-slider ui-corner-all ui-slider-horizontal ui-widget ui-widget-content"></div>
+        <input value="" placeholder="" class="form-control int" type="text">
+    </div>
+    <br/><br/><br/>
     <div class="sliderInput" id="axialStiffness">
         <span class="label-slider">Axial Stiffness : </span><div class="flat-slider ui-slider ui-corner-all ui-slider-horizontal ui-widget ui-widget-content"></div>
         <input value="" placeholder="" class="form-control int" type="text">

js/controls.js

@@ -56,6 +56,10 @@ function initControls(globals){
         globals.dynamicModel.reset();
     });
 
+    setSliderInput("#creaseAngle", globals.creaseAngle, 0, Math.PI, 0.1, function(val){
+        globals.creaseAngle = val;
+    });
+
     function setDeltaT(val){
         $("#deltaT").html(val.toFixed(4));
     }

js/crease.js

+/**
+ * Created by amandaghassaei on 2/25/17.
+ */
+
+function Crease(edge, face1Index, face2Index, targetTheta, node1, node2){
+
+    //face1 corresponds to node1, face2 to node2
+    this.edge = edge;
+    this.face1Index = face1Index;
+    this.face2Index = face2Index;
+    this.targetTheta = targetTheta;
+    this.node1 = node1;
+    this.node2 = node2;
+    node1.addCrease(this);
+    node2.addCrease(this);
+}
+
+Crease.prototype.getLength = function(){
+    return this.edge.getLength();
+};
+
+Crease.prototype.getVector = function(){
+    return this.edge.getVector();
+};
+
+Crease.prototype.getNormal1Index = function(){
+    return this.face1Index;
+};
+
+Crease.prototype.getNormal2Index = function(){
+    return this.face2Index;
+};
+
+Crease.prototype.destroy = function(){
+    this.node1.removeCrease(this);
+    this.node2.removeCrease(this);
+    this.edge = null;
+    this.face1Index = null;
+    this.face2Index = null;
+    this.targetTheta = null;
+    this.node1 = null;
+    this.node2 = null;
+};
\ No newline at end of file

js/globals.js

@@ -19,6 +19,7 @@ function initGlobals(){
         schematicVisible: true,
 
         //sim settings
+        creaseAngle: 0,
         axialStiffness: 100,
         creaseStiffness: 1,
         panelStiffness: 1,

js/model.js

@@ -21,6 +21,9 @@ function initModel(globals){
     edges.push(new Beam([nodes[3], nodes[0]]));
     edges.push(new Beam([nodes[3], nodes[2]]));
 
+    var creases = [];
+    creases.push(new Crease(edges[1], 1, 0, 0, nodes[1], nodes[0]));
+
     _.each(nodes, function(node){
         globals.threeView.sceneAddModel(node.getObject3D());
     });
@@ -36,8 +39,13 @@ function initModel(globals){
         return edges;
     }
 
+    function getCreases(){
+        return creases;
+    }
+
     return {
         getNodes: getNodes,
-        getEdges: getEdges
+        getEdges: getEdges,
+        getCreases: getCreases
     }
 }
\ No newline at end of file

js/node.js

@@ -22,6 +22,7 @@ function Node(position, index){
     this.object3D._myNode = this;
 
     this.beams = [];
+    this.creases = [];
     this.externalForce = null;
     this.fixed = false;
 
@@ -78,6 +79,16 @@ Node.prototype.getMass = function(){
 
 
 
+Node.prototype.addCrease = function(crease){
+    this.creases.push(crease);
+};
+
+Node.prototype.removeCrease = function(crease){
+    if (this.creases === null) return;
+    var index = this.creases.indexOf(crease);
+    if (index>=0) this.creases.splice(index, 1);
+};
+
 
 Node.prototype.addBeam = function(beam){
     this.beams.push(beam);
@@ -163,5 +174,6 @@ Node.prototype.destroy = function(){
     this.object3D._myNode = null;
     this.object3D = null;
     this.beams = null;
+    this.creases = null;
     this.externalForce = null;
 };
\ No newline at end of file