import java.awt.Color; import java.util.Vector; import java.util.Enumeration; import Ray; public class Surface { public float ir, ig, ib; // surface's intrinsic color public float ka, kd, ks, ns; // constants for phong model public float kt, kr, nt; private static final float TINY = 0.001f; private static final float I255 = 0.00392156f; // 1/255 public Surface(float rval, float gval, float bval, float a, float d, float s, float n, float r, float t, float index) { ir = rval; ig = gval; ib = bval; ka = a; kd = d; ks = s; ns = n; kr = r*I255; kt = t*I255; nt = index; // CHANGED kt = t to kt = t*I255 } public Color Shade(Vector3D p, Vector3D n, Vector3D v, Vector lights, Vector objects, Color bgnd, boolean inside) { // boolean is NEW // p: the point of intersection // n: a unit-length surface normal // v: a unit-length vector towards the ray's origin if (inside) { // NEW n.x = -n.x; n.y = -n.y; n.z = -n.z; } Enumeration lightSources = lights.elements(); float r = 0; float g = 0; float b = 0; while (lightSources.hasMoreElements()) { Light light = (Light) lightSources.nextElement(); if (light.lightType == Light.AMBIENT) { r += ka*ir*light.ir; g += ka*ig*light.ig; b += ka*ib*light.ib; } else { Vector3D l; if (light.lightType == Light.POINT) { // l is the direction from the light to the ray's // point of intersection l = new Vector3D(light.lvec.x - p.x, light.lvec.y - p.y, light.lvec.z - p.z); l.normalize(); } else { // DIRECTIONAL l = new Vector3D(-light.lvec.x, -light.lvec.y, -light.lvec.z); } // Check if the surface point is in shadow Vector3D poffset = new Vector3D(p.x + TINY*l.x, p.y + TINY*l.y, p.z + TINY*l.z); Ray shadowRay = new Ray(poffset, l); if (shadowRay.trace(objects)) break; float lambert = Vector3D.dot(n,l); if (lambert > 0) { if (kd > 0) { float diffuse = kd*lambert; r += diffuse*ir*light.ir; g += diffuse*ig*light.ig; b += diffuse*ib*light.ib; } if (ks > 0) { lambert *= 2; float spec = v.dot(lambert*n.x - l.x, lambert*n.y - l.y, lambert*n.z - l.z); if (spec > 0) { spec = ks*((float) Math.pow((double) spec, (double) ns)); r += spec*light.ir; g += spec*light.ig; b += spec*light.ib; } } } } } // Compute illumination due to reflection //if ((kr > 0) || false) { if (kr > 0) { float t = v.dot(n); // Magnitude of v in direction of normal if (t > 0) { /////////////////////////////////////////////////////////// // v t*n reflect // ._ + _. // |\ /|\ /| // \ | / // \ | / // \|/ // ------------ /////////////////////////////////////////////////////////// t *= 2; Vector3D reflect = new Vector3D(t*n.x - v.x, t*n.y - v.y, t*n.z - v.z); Vector3D poffset = new Vector3D(p.x + TINY*reflect.x, p.y + TINY*reflect.y, p.z + TINY*reflect.z); Ray reflectedRay = new Ray(poffset, reflect); if (reflectedRay.trace(objects)) { // NEW //////////////////////////////////////////////// if (inside) { // NEW Ray.depth++; //System.out.println("depth = "+Ray.depth); if (Ray.depth >= RayTrace.MAXDEPTH) { //System.out.println("Reset"); Ray.depth = 0; return new Color(0, 0, 0); } } Color rcolor = reflectedRay.Shade(lights, objects, bgnd); r += kr*rcolor.getRed(); g += kr*rcolor.getGreen(); b += kr*rcolor.getBlue(); //if (inside) { // NEW // System.out.println("r: "+r); // System.out.println("g: "+g); // System.out.println("b: "+b); //} } else { r += kr*bgnd.getRed(); g += kr*bgnd.getGreen(); b += kr*bgnd.getBlue(); } } } /////////////////////////////////////////////////////////////////// // R E F R A C T I O N /////////////////////////////////////////////////////////////////// // v n reflect // ._ + _. // |\ A /|\ /| // \ i | / // \ | / // \ | / // \ | / // \ | / // \|/ // ------------------- // |\ // | \ // | \ // | \ // | A \ // | r \ // \|/ _\| // + * // -n refract /////////////////////////////////////////////////////////////////// // Snell's Law: n *sin(A )=n *sin(A ) // i i t t /////////////////////////////////////////////////////////////////// //if ((kt > 0) || false) { if (kt > 0) { float nt_real = nt; if (inside) nt_real = 1/nt; /////////////////////////////////////////////////////////// // v.dot(n) = |v| * |n| * cos (A ) // i // v.dot(n) // cos (A ) = ---------- = v.dot(n) // i 1 * 1 /////////////////////////////////////////////////////////// // _____________________________ // / 2 2 // cos (A ) = -+ / 1 - ( n ) * ( 1 - cos A ) // r \/ t i /////////////////////////////////////////////////////////// // refract = n * (-v) - (cos A - n * cos A )*n // t r t i /////////////////////////////////////////////////////////// float cosAi = v.dot(n); if (cosAi > 0) { float cos2Ar = 1 - ((nt_real*nt_real) * (1 - (cosAi*cosAi))); float cosAr = (float) Math.sqrt((double) cos2Ar); Vector3D refract = new Vector3D(); refract.x = -nt_real*v.x - (cosAr - nt_real*cosAi)*n.x; refract.y = -nt_real*v.y - (cosAr - nt_real*cosAi)*n.y; refract.z = -nt_real*v.z - (cosAr - nt_real*cosAi)*n.z; Vector3D poffset = new Vector3D(p.x + TINY*refract.x, p.y + TINY*refract.y, p.z + TINY*refract.z); Ray refractedRay = new Ray(poffset, refract); if (refractedRay.trace(objects)) { //System.out.println("Refracted ray hit"); Color rcolor = refractedRay.Shade(lights, objects, bgnd); r += kt*rcolor.getRed(); g += kt*rcolor.getGreen(); b += kt*rcolor.getBlue(); } else { //System.out.println("Refracted ray didn't hit"); //debug r += kt*bgnd.getRed(); g += kt*bgnd.getGreen(); b += kt*bgnd.getBlue(); } } } // if (inside) { // NEW // System.out.println("r: "+r); // System.out.println("g: "+g); // System.out.println("b: "+b); // } r = (r > 1f) ? 1f : r; g = (g > 1f) ? 1f : g; b = (b > 1f) ? 1f : b; return new Color(r, g, b); } }