{ "X3D": { "encoding":"UTF-8", "@profile":"Immersive", "@version":"3.0", "@xsd:noNamespaceSchemaLocation":"https://www.web3d.org/specifications/x3d-3.0.xsd", "JSON schema":"https://www.web3d.org/specifications/x3d-4.0-JSONSchema.autogenerated.json", "head": { "meta": [ { "@name":"title", "@content":"ProjectileInterpolatorPrototype.x3d" }, { "@name":"description", "@content":"A proto which simulates x-y plane projectile motion." }, { "@name":"creator", "@content":"Ozan APAYDIN" }, { "@name":"created", "@content":"10 December 2001" }, { "@name":"modified", "@content":"30 November 2024" }, { "@name":"identifier", "@content":"https://www.web3d.org/x3d/content/examples/Basic/StudentProjects/ProjectileInterpolatorPrototype.x3d" }, { "@name":"generator", "@content":"X3D-Edit 3.3, https://www.web3d.org/x3d/tools/X3D-Edit" }, { "@name":"license", "@content":"../license.html" }, { "@name":"translated", "@content":"20 April 2026" }, { "@name":"generator", "@content":"X3dToJson.xslt, https://www.web3d.org/x3d/stylesheets/X3dToJson.html" }, { "@name":"reference", "@content":"X3D JSON encoding: https://www.web3d.org/wiki/index.php/X3D_JSON_Encoding" } ] }, "Scene": { "-children":[ { "WorldInfo": { "@title":"ProjectileInterpolatorPrototype.x3d" } }, { "ProtoDeclare": { "@name":"ProjectileInterpolator", "@appinfo":"This prototype is a Projectile Motion Interpolator. It takes Inputs : Initial Velocity and Angle then calculates trajectory of the projectile on x-y plane according to given dt time and B_m. It outputs value_changed values(SFVec3f).", "ProtoInterface": { "field": [ { "@name":"Vi", "@accessType":"initializeOnly", "@appinfo":"Initial Velocity value of the object.", "@type":"SFFloat", "@value":0.0 }, { "@name":"theta", "@accessType":"initializeOnly", "@appinfo":"Launch Angle. The angle between horizantal and launch direction", "@type":"SFFloat", "@value":0.0 }, { "@name":"B_m", "@accessType":"initializeOnly", "@appinfo":"Proportional to drag force = B2/m", "@type":"SFFloat", "@value":0.00004 }, { "@name":"dt", "@accessType":"initializeOnly", "@appinfo":"Time step.", "@type":"SFFloat", "@value":0.1 }, { "@name":"fraction", "@accessType":"initializeOnly", "@appinfo":"SFFloat Values ranging [0..1].", "@type":"SFFloat", "@value":0.05 }, { "@name":"set_fraction", "@accessType":"inputOnly", "@appinfo":"The set_fraction eventIn receives an SFFloat event and causes the interpolator function to evaluate resulting in a value_changed eventOut with the same timestamp as the set_fraction event.", "@type":"SFFloat" }, { "@name":"set_theta", "@accessType":"inputOnly", "@appinfo":"Sets theta to the value of eventIn.", "@type":"SFFloat" }, { "@name":"set_Vi", "@accessType":"inputOnly", "@appinfo":"Sets Vi to the value of eventIn.", "@type":"SFFloat" }, { "@name":"value_changed", "@accessType":"outputOnly", "@appinfo":"The interpolator function eventOut results as Vector3Float.", "@type":"SFVec3f" } ] }, "ProtoBody": { "-children":[ { "Script": { "@DEF":"ProjectileMotionTrackerScript", "field": [ { "@name":"Vi", "@accessType":"initializeOnly", "@type":"SFFloat" }, { "@name":"theta", "@accessType":"initializeOnly", "@type":"SFFloat" }, { "@name":"B_m", "@accessType":"initializeOnly", "@type":"SFFloat" }, { "@name":"dt", "@accessType":"initializeOnly", "@type":"SFFloat" }, { "@name":"fraction", "@accessType":"initializeOnly", "@appinfo":"In range [01]", "@type":"SFFloat" }, { "@name":"set_fraction", "@accessType":"inputOnly", "@type":"SFFloat" }, { "@name":"set_theta", "@accessType":"inputOnly", "@type":"SFFloat" }, { "@name":"set_Vi", "@accessType":"inputOnly", "@type":"SFFloat" }, { "@name":"value_changed", "@accessType":"outputOnly", "@type":"SFVec3f" } ], "IS": { "connect": [ { "@nodeField":"Vi", "@protoField":"Vi" }, { "@nodeField":"theta", "@protoField":"theta" }, { "@nodeField":"B_m", "@protoField":"B_m" }, { "@nodeField":"dt", "@protoField":"dt" }, { "@nodeField":"fraction", "@protoField":"fraction" }, { "@nodeField":"set_fraction", "@protoField":"set_fraction" }, { "@nodeField":"set_theta", "@protoField":"set_theta" }, { "@nodeField":"set_Vi", "@protoField":"set_Vi" }, { "@nodeField":"value_changed", "@protoField":"value_changed" } ] }, "#sourceCode":[ "", "", "ecmascript:", "var x;", "var y;", "var Vx;", "var Vy;", "var B_m;", "var dt;", "var blocksize;", "var Vi;", "var theta;", "", "var key;", "var keyValue;", "var previousFraction;", "var previousFractionIndex;", "var blockSize;", "var outputArray;", "", "function tracePrint (outputString)", "{", "\tvar traceEnabled = true;", "\tif (traceEnabled) Browser.println ('[WaypointInterpolator]' + outputString);", "}", "function alwaysPrint (outputString)", "{", "\tBrowser.println ('[WaypointInterpolator]' + outputString);", "}", "", "", "", "function initialize() {", " key = new Array();", " keyValue = new MFVec3f();", " x = new Array();", " y = new Array();", " calculateTrajectory();", "", " previousFractionIndex = -1;", "\tpreviousFraction = 0;", "\t// check key array ranges [0..1] and is monotonically increasing", "\t// check that size of keyValue array is integer multiple of size of key array", "\ttracePrint ('key =' + key);", "\ttracePrint ('key.length= ' + key.length);", "\ttracePrint ('keyValue= ' + keyValue);", "\ttracePrint ('keyValue.length=' + keyValue.length);", "\tblockSize = 3; //keyValue.length/key.length;", "\ttracePrint ('blockSize=' + blockSize);", "\tif (blockSize != Math.round(blockSize))", "\t{", "\t alwaysPrint ('*** warning: blockSize not an integer multiple. check sizes of key and keyValue');", "\t}", "\tif (key[0] != 0)", "\t{", "\t alwaysPrint ('*** warning: key[0] != 0');", "\t}", "\tif (key[key.length-1] != 1)", "\t{", "\t alwaysPrint ('*** warning: key[' + (key.length - 1) + '] != 1, reset from' + key[key.length-1] + ' to 1');", "\t key[key.length-1] = 1;", "\t}", "\tfor (index = 0; index < blockSize; index++)", "\t{", "\t\tif ((key[index] < 0) || (key[index] > 1))", "\t\t{", "\t\t alwaysPrint ('*** warning: key[' + index + '] =' + key[index] + ', out of range [0..1]');", "\t\t}", "\t}", "\t// instantiate default array, later computations just update it", "\toutputArray = new SFVec3f();", "\toutputArray = keyValue[0];", "\ttracePrint ('initial outputArray=' + outputArray);", "", "}", "", "function set_fraction (inputFloat, timestamp) {", "\tfraction = inputFloat;", "\ttracePrint ('previousFractionIndex=' + previousFractionIndex", "\t\t + ', fraction=' + fraction + ', previousFraction=' + previousFraction);", "", "\tif (fraction < 0)", "\t{", "\t\ttracePrint ('*** illegal fraction' + fraction + ' set to 0');", "\t\tfraction = 0;", "\t\tpreviousFractionIndex = 0; // first", "\t}", "\telse if (fraction > 1)", "\t{", "\t\talwaysPrint ('*** illegal fraction' + fraction + ' set to 1');", "\t\tfraction = 1;", "\t\tpreviousFractionIndex = blockSize - 1; // last", "\t}", "\telse if (previousFractionIndex == -1)", "\t{", "\t\tpreviousFractionIndex = 0; // first", "\t\ttracePrint ('previousFractionIndex initialized for first event');", "\t}", "\telse if ((fraction >= previousFraction) && (fraction >= key[previousFractionIndex+1]))", "\t{", "\t\tpreviousFractionIndex++;", "\t}", "\telse if (fraction < previousFraction) // regress, or loop repeat without reaching one", "\t{", "", "\t\tpreviousFractionIndex = 0;", "\t\twhile ((fraction >= key[previousFractionIndex+1]) && (previousFractionIndex < blockSize))", "\t\t{", "\t\t\tpreviousFractionIndex++;", "\t\t}", "\t\ttracePrint ('reset/reincrement previousFractionIndex to' + previousFractionIndex);", "\t}", "", "\tif (fraction == 1) // use final block", "\t{", "\t\ttracePrint ('(fraction == 1)');", "", "", " \toutputArray = keyValue[(keyValue.length -1)];", "", "\t\tpreviousFractionIndex = -1; // setup for restart", "\t\ttracePrint ('finished final fraction==1 block');", "\t}", "\t// when fraction matches index, calculate value_changed from corresponding keyValue array", "\telse if (fraction == key[previousFractionIndex])", "\t{", "\t\ttracePrint ('(fraction == key[previousFractionIndex])');", "", "", "\t\t// update outputArray - need to interpolate next", "\t\toutputArray = keyValue[previousFractionIndex];", "", "\t}", " else {", "", " delta = key[previousFractionIndex + 1] - key[previousFractionIndex];", " differ = fraction - key[previousFractionIndex];", " percentDiffer = differ / delta;", "", " valueDelta = new SFVec3f();", " for(index = 0; index < blockSize; index++) {", " valueDelta[index] = keyValue[(previousFractionIndex + 1)][index] - keyValue[previousFractionIndex][index];", " outputArray[index] = keyValue[previousFractionIndex][index] + valueDelta[index] * percentDiffer;", "\t\t Browser.println ('valueDelta' + valueDelta[index]);", " Browser.println ('perDiffer' + percentDiffer);", " }", "", " }", "", "\tvalue_changed = outputArray;", "\tpreviousFraction = fraction;", "\ttracePrint ('value_changed=' + value_changed);", "", "}", "", "", "function set_Vi(initialVelocity, timeStamp) {", " Vi = initialVelocity;", " initialize(timeStamp);", "}", "", "", "function set_theta(angle, timeStamp) {", " theta = angle;", " initialize(timeStamp);", "}", "", "", "function calculateTrajectory() {", "", " x[0] = 0;", " y[0] = 0;", "", " var timeKeys = new Array();", " timeKeys[0] = 0.0;", "", " //convert degree to radian", " angle = Math.PI * theta / 180;", "", " Vx = Vi * Math.cos(angle);", " Vy = Vi * Math.sin(angle);", "", " var i = 0;", "", " do {", " i = i + 1;", " timeKeys[i] = timeKeys[i - 1] + dt;", " Browser.println ('timeKeys' + timeKeys[i]);", " x[i] = x[i - 1] + Vx * dt;", " y[i] = y[i - 1] + Vy * dt;", "", "", " f = B_m * Math.sqrt(Vx * Vx + Vy * Vy) * Math.exp(-y[i] / 0.0001);", "", " Vy = Vy - 9.8 * dt - f * Vy * dt;", " Vx = Vx - f * Vx * dt;", " Browser.println ('Vy' + Vy);", " }while(y[i] > 0);", " Browser.println ('Im here' + x.length);", "", " //interpolate to find landing point", " var a = -y[i] / y[i-1];", " x[i] = (x[i] + a * x[i-1]) / (1+a);", " y[i] = 0;", "", " //copy x, y values to keyValues", " copyToKeyValues();", " //finding keys", " for(j = 0; j < timeKeys.length; j++) {", " key[j] = timeKeys[j] / timeKeys[timeKeys.length - 1];", " Browser.println (' ' + key[j]);", "", " }", "", "}", "", "function copyToKeyValues() {", " for(i = 0; i < x.length; i++) {", " Browser.println ('x' + x[i]);", " keyValue[i][0] = x[i];", " keyValue[i][1] = y[i];", " keyValue[i][2] = 0;", " Browser.println ('keyValue' + i + ' ' + keyValue[i][0]);", " }", "", "}", "", "" ] } } ] } } }, { "#comment":"====================" }, { "Anchor": { "@description":"ProjectileInterpolatorArena", "@parameter":["target=_blank"], "@url":["ProjectileInterpolatorArena.wrl","https://www.web3d.org/x3d/content/examples/Basic/StudentProjects/ProjectileInterpolatorArena.wrl","ProjectileInterpolatorArena.x3d","https://www.web3d.org/x3d/content/examples/Basic/StudentProjects/ProjectileInterpolatorArena.x3d"], "-children":[ { "Shape": { "-geometry": { "Text": { "@string":["ProjectileInterpolatorPrototype","defines a prototype","Click on this text to see","ProjectileInterpolatorArena"," scene"], "-fontStyle": { "FontStyle": { "@justify":["MIDDLE","MIDDLE"], "@size":0.7 } } } }, "-appearance": { "Appearance": { "-material": { "Material": { "@diffuseColor":[1,1,0.2] } } } } } } ] } }, { "PositionInterpolator": { } } ] } } }