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Raytracer
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<html> | |
<head> | |
<title>Raytrace</title> | |
<script type="text/javascript" src="vector.js"></script> | |
<script type="text/javascript" src="raytracer.js"></script> | |
</head> | |
<body> | |
<canvas id="raytraceCanvas" width="100" height="100"> | |
get off of internet explorer | |
</canvas> | |
</body> | |
</html> |
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var Sphere = function(position, r, color) { //color in form [r, g, b] | |
this.position = position; | |
this.x = position.x; | |
this.y = position.y; | |
this.z = position.z; | |
this.r = r; | |
this.color = color; | |
} | |
//z = up | |
var Camera = function(direction, position) { //rotation on the x, y, and z axis | |
this.createRays = function(distanceX, distanceZ) { | |
for(var i = 0; i < canvas.width; i++) { | |
for(var j = 0; j < canvas.height; j++) { | |
var currentRay = new Ray(direction, new Vector.Rect((position.x + (i * distanceX)) - (position.x + (canvas.width * distanceX)) / 2, position.y, position.z + (j * distanceZ) - (position.z + (canvas.height * distanceZ)) / 2), [i, j]); | |
currentRay.update(); | |
} | |
} | |
} | |
} | |
//each ray is a polar vector and a rectangular vector | |
//the polar vector, (magnitude, rx, rz), says the length and direction | |
//the rectangular vector, (x, y, z), says the origin or last reflection of the ray | |
//rotation on the x axis moves ray in the z directions | |
//rotation on the z axis moves ray in the x directions | |
//rotation on the y axis is "tilt", it isn't necessary for a ray. x and z are all that are needed to point in any direction | |
//y = forward (movement if no angle) | |
var precision = 0.1; //lower number = higher precision (0 bounded) | |
var maxIterations = 150; //max times that a ray can go without rendering as white | |
var Ray = function(direction, position, pixel) { //pixel = what pixel this ray was sent from | |
this.color = "#FFFFFF"; | |
this.iterations = 0; | |
this.done = false; | |
this.draw = function() { | |
ctx.fillStyle = this.color; | |
ctx.fillRect(pixel[0], pixel[1], 1, 1); | |
} | |
this.update = function() { | |
while(!this.done) { | |
this.iterations += 1; | |
position.x += -precision * Math.sin(direction.rz); //trig functions take radians | |
position.y += precision * Math.cos(direction.rx); | |
position.z += precision * Math.sin(direction.rx); | |
//console.log(position.z.toString()) | |
for (var sphereIndex = 0; sphereIndex < Scene.length; sphereIndex++) { | |
var currentSphere = Scene[sphereIndex]; | |
//console.log(position.toString() + " rect = " + (Vector.subtract(position, currentSphere.position)).toString() + " polar = " + (Vector.subtract(position, currentSphere.position).toPolar()).toString()); | |
//if (Math.abs(position.x - currentSphere.x) < currentSphere.r + contactMarginOfError && | |
// Math.abs(position.y - currentSphere.y) < currentSphere.r + contactMarginOfError && | |
// Math.abs(position.z - currentSphere.z) < currentSphere.r + contactMarginOfError) { //if a ray is colliding with a sphere | |
var distanceToSphere = Vector.subtract(currentSphere.position, position).toPolar().magnitude; | |
//console.log(distanceToSphere.toString()); | |
if(distanceToSphere < currentSphere.r) { | |
this.bounces += 1; | |
this.color = "#FF0000"; | |
this.done = true; | |
//to reflect a vector over a normal: | |
//Vnew = -2*(V dot N)*N + V | |
} | |
} | |
if(this.iterations > maxIterations) { | |
this.done = true; | |
} | |
} | |
//console.log("~~~~~~~~~"); | |
this.draw(); | |
} | |
} | |
window.onload = function() { | |
canvas = document.getElementById("raytraceCanvas"); | |
ctx = canvas.getContext("2d"); | |
Scene = [(new Sphere(new Vector.Rect(0, 6, 0), 24, "#FF0000"))]; | |
SceneCamera = new Camera(new Vector.Polar(1, 0, 0), new Vector.Rect(0,0,0)); | |
//SceneCamera.createRays(); | |
} |
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var Vector = {}; | |
Vector.Rect = function(x, y, z) { | |
this.magnitude = Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2) + Math.pow(z, 2)); | |
this.toRect = function() { return this; } | |
this.toPolar = function() { return new Vector.Polar(this.magnitude, Math.acos(z/this.magnitude), Math.atan2(y, x)) } | |
this.x = x; | |
this.y = y; | |
this.z = z; | |
this.toString = function() { return "(" + x.toString() + ", " + y.toString() + ", " + z.toString() + ")" } | |
} | |
Vector.Polar = function(magnitude, rx, rz) { //rz = theta, rx = phi | |
//this._vec = new Vector.Rect(-magnitude * Math.cos(rz), magnitude * Math.sin(rz), magnitude * Math.cos(rx)); | |
this._vec = new Vector.Rect(Math.cos(rz) * Math.cos(rx) * magnitude, Math.sin(rz) * Math.cos(rx) * magnitude, Math.sin(rx) * magnitude); | |
this.magnitude = magnitude; | |
this.toRect = function() { return new this._vec; } | |
this.toPolar = function() { return this; } | |
this.rx = rx; | |
this.rz = rz; | |
this.toString = function() { return "(" + magnitude.toString() + ", " + rx.toString() + ", " + rz.toString() + ")" } | |
} | |
Vector.add = function(v1, v2) { | |
return new Vector.Rect(v1.toRect().x + v2.toRect().x, v1.toRect().y + v2.toRect().y, v1.toRect().z + v2.toRect().z); | |
} | |
Vector.subtract = function(v1, v2) { | |
return new Vector.Rect(v1.toRect().x - v2.toRect().x, v1.toRect().y - v2.toRect().y, v1.toRect().z - v2.toRect().z); | |
} | |
Vector.product = function(s,v) { | |
return new Vector.Rect(s * v.toRect().x, s * v.toRect().y, s * v.toRect().z); | |
} | |
Vector.dotProduct = function(v1, v2) { | |
return (v1.toRect().x * v2.toRect().x + v1.toRect().y * v2.toRect().y + v1.toRect().z * v2.toRect().z); | |
} | |
Vector.crossProduct = function(v1, v2) { | |
return new Vector.Rect(v1.toRect().y * v2.toRect().z - v1.toRect().z * v2.toRect().y, v1.toRect().z * v2.toRect().x - v1.toRect().x * v2.toRect().z, v1.toRect().x * v2.toRect().y - v1.toRect().y * v2.toRect().x); | |
} |
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