private MyRay shootPixelRay(int x, int y) {
MyRay out = new MyRay();
float xPart, yPart;
xPart = (rightViewPlane - leftViewPlane) / widthPix;
yPart = (topViewPlane - bottomViewPlane) / heightPix;
xPart = leftViewPlane + (float) 0.5 * xPart + ((float) x) * xPart;
yPart = bottomViewPlane + (float) 0.5 * yPart + ((float) y) * yPart;
// get ray direction and origin: perspective
// out.setOrigin(viewer);
// MyPoint3D dir = new MyPoint3D(xPart - viewer.getX(), yPart - viewer.getY(), zViewPlane -
// viewer.getZ());
// get ray direction and origin: perpendicular
out.setOrigin(new MyPoint3D(xPart, yPart, viewer.getZ()));
MyPoint3D dir = new MyPoint3D(0, 0, 1);
// normalize
dir.normalize();
out.setDirection(dir);
return out;
}
private MyColor traceRay(MyRay ray, int recursionLevel) {
// MyColor color = MyColor.BLACK;
MyColor color = new MyColor(0, 0, 0);
float maxDist = Float.POSITIVE_INFINITY;
if (recursionLevel > 10) {
System.out.println("recursion limit reached");
return color;
}
// check each object for intersections
// --> get the one with shortest distance
MyShape currentShape = null;
for (MyShape shape : objects) {
CalcTuple resultTuple = shape.rayIntersect(ray);
float hitDist = resultTuple.getClosestIntersection();
if (hitDist > zViewPlane - viewer.getZ() && maxDist > hitDist) {
maxDist = hitDist;
currentShape = shape;
}
}
MyPoint3D intersection;
MyPoint3D normal;
// set pixel in buffer
if (maxDist < Float.POSITIVE_INFINITY) {
// we got an intersection
// -> check for light source
// shoot from intersection point in points surface normal direction
intersection = ray.getOrigin().add(ray.getDirection().mul(maxDist));
normal = currentShape.getNormal(intersection);
// --------- REFLECTED LIGHT ------------
// float specularLight = getReflection(ray,intersection,normal,currentShape);
// Rref = Rin - 2*N(Rin*N)
MyPoint3D reflectedDir =
ray.getDirection().sub(normal.mul(2).mul(ray.getDirection().dotProduct(normal)));
// shoot reflected ray
MyRay reflectedRay = shootRay(intersection, reflectedDir);
MyColor reflectedColor = traceRay(reflectedRay, recursionLevel + 1);
color =
color.add(
new MyColor(
(int) (reflectedColor.getRed() * currentShape.getMaterial().getSpecularC()),
(int) (reflectedColor.getGreen() * currentShape.getMaterial().getSpecularC()),
(int) (reflectedColor.getBlue() * currentShape.getMaterial().getSpecularC())));
// --------- AMBIENT LIGHT --------------
// get ambient light component
float ambientLight = getAmbientComponent(currentShape);
color =
color.add(
new MyColor(
(int) (currentShape.getMaterial().getColor().getRed() * ambientLight),
(int) (currentShape.getMaterial().getColor().getGreen() * ambientLight),
(int) (currentShape.getMaterial().getColor().getBlue() * ambientLight)));
// ---- DIFFUSED LIGHT --------
// float diffLight = 0;
for (LightSource source : lights) {
// check if normal points towards light source
if (source.intersects(currentShape.getNormal(intersection))) {
// now we shoot a ray from the intersection point and see
// if any other object is in our way --> shadowed?
MyRay ray2 = shootRay(intersection, source.getOrigin().sub(intersection));
boolean isShadowed = false;
for (MyShape shape : objects) {
CalcTuple resultTuple = shape.rayIntersect(ray2);
if (shape != currentShape) {
// check if we got an intersection
if (resultTuple.getRoots() > 0) {
isShadowed = true;
break;
}
}
// check if our own body blocks
else {
if (resultTuple.getRoots() > 1) {
isShadowed = true;
break;
}
}
}
// in case we are not shadowed -> calculate new light
if (!isShadowed) {
// get diffused light component
// diffLight += getDiffuseComponent(source, normal, intersection, currentShape);
// TODO: hier fehlt noch irgendnen specular coeff bestimmt :)
// float diff = getDiffuseComponent(source, normal, intersection, currentShape );
MyPoint3D dir = source.getOrigin().sub(intersection);
float diff =
(float) currentShape.getMaterial().getDiffuseC()
* dir.dotProduct(normal)
/ (float)
(Math.sqrt(dir.dotProduct(dir)) * Math.sqrt(normal.dotProduct(normal)));
if (diff > 1) {
// System.out.println("diff");
diff = 1;
}
if (diff > 0) {
// color = color.add( source.getColor().dim(diff) );
color =
color.add(currentShape.getMaterial().getColor().mix(source.getColor()).dim(diff));
} else {
// color = color.sub( source.getColor().dim(-diff) );
}
}
}
}
} // end if shape hit
return color;
}