Added sphere intersection code. Looks like an ellipse for some reason…

…, need some fix

core/primitive/Plane.js

@@ -11,4 +11,8 @@ Plane.prototype.getIntersection = function(ray) {
 	return ray.pointAtDistance(t);
 }
 
+Plane.prototype.getNormal = function(point) {
+	return this.normal;
+}
+
 module.exports = Plane;

core/primitive/Rectangle.js

@@ -22,7 +22,7 @@ Rectangle.prototype.getIntersection = function(ray) {
 }
 
 Rectangle.prototype.getNormal = function(point) {
-	return this.normal;
+	return Plane.prototype.getNormal.call(this, point);
 }
 
 module.exports = Rectangle;

core/primitive/Sphere.js

@@ -1,7 +1,29 @@
-function Sphere(x, y, z, r) {
+var Vector = require("../common/Vector");
 
+function Sphere(x, y, z, r) {
+	this.x = x;
+	this.y = y;
+	this.z = z;
+	this.r = r;
 }
 
 Sphere.prototype.getIntersection = function(ray) {
-
-}
+	var a = ray.direction.dot(ray.direction);
+	var oc = new Vector(ray.origin.x - this.x, ray.origin.y - this.y, ray.origin.z - this.z);
+	var b = 2 * (oc.dot(ray.direction));
+	var c = oc.dot(oc) - this.r * this.r;
+	var detSq = b * b - 4 * a * c;
+	if (detSq < 0) {
+		return null;
+	}
+	var det = Math.sqrt(detSq);
+	var t0 = (-b - det) / (2 * a);
+	var t1 = (-b + det) / (2 * a);
+	return ray.pointAtDistance(t0);	//this is the closer of the two intersection points. the other will be useful for refraction maybe?
+}
+
+Sphere.prototype.getNormal = function(point) {
+	return new Vector(point.x - this.x, point.y - this.y, point.z - this.z);
+}
+
+module.exports = Sphere;

core/renderer/SimpleRenderer.js

@@ -1,8 +1,11 @@
 var Point = require('../common/Point');
 var Ray = require('../common/Ray');
 var Vector = require('../common/Vector');
+
 var Plane = require('../primitive/Plane');
 var Rectangle = require('../primitive/Rectangle');
+var Sphere = require('../primitive/Sphere');
+
 var Color = require('../image/Color');
 var PNG = require("pngjs").PNG;
 var fs = require('fs');
@@ -25,6 +28,11 @@ exports.render = function(data, socket) {
 		var x = aspectRatio * ((w / data.camera.imageWidth) - 0.5);
 		for (var h = 0; h < data.camera.imageHeight; h++) {
 			var idx = (png.width * (png.height - h) + w) << 2;
+			png.data[idx] = 0;
+			png.data[idx+1] = 0;
+			png.data[idx+2] = 0;
+			png.data[idx+3] = 255;
+
 			var y = (h / data.camera.imageHeight) - 0.5;
 			var cameraPlaneIntersectionPoint = cameraPlaneCenter.add(cameraRight.multiply(x)).add(cameraUp.multiply(y));
 			var ray = new Ray(cameraPos, cameraPos.vectorTo(cameraPlaneIntersectionPoint));
@@ -40,23 +48,22 @@ exports.render = function(data, socket) {
 							primitive.height
 						);
 				}
+				else if (primitive.type == "sphere") {
+					shape = new Sphere(primitive.center.x, primitive.center.y, primitive.center.z, primitive.radius);
+				}
 				else {
 					continue;
 				}
 				var intersectionPoint = shape.getIntersection(ray);
-				if (!intersectionPoint) {
-					png.data[idx] = 0;
-					png.data[idx+1] = 0;
-					png.data[idx+2] = 0;
-					png.data[idx+3] = 255;
-				}
-				else {
+				if (intersectionPoint) {
 					var color = _getColor(data.lights, primitive.material, intersectionPoint, shape.getNormal(intersectionPoint));
 					png.data[idx] = color.r;
 					png.data[idx+1] = color.g;
 					png.data[idx+2] = color.b;
 					png.data[idx+3] = 255;
 				}
+				else {
+				}
 			}
 		}
 		var percent = (100.0 * w/data.camera.imageWidth) | 0;

public/js/scene.js

@@ -32,13 +32,13 @@ function doRender() {
 		},{
 			type: 'sphere',
 			center: {
-				x: 10, y: 10, z: 10
+				x: 5, y: -5, z: 35
 			},
-			radius: 5,
+			radius: 1,
 			material: {
 				type: 'diffuse',
 				color: {
-					r: 255, g: 0, b: 0
+					r: 255, g: 0, b: 255
 				}
 			}
 		}],
@@ -62,8 +62,8 @@ function doRender() {
 				x: 0, y: 1, z: 0
 			},
 			zoom: 1,
-			imageWidth: 300,
-			imageHeight: 400
+			imageWidth: 600,
+			imageHeight: 800
 		}
 	};
 	socket.emit('doRender', sceneData);