Task: Death Star





Java: import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.geometry.Point3D;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.scene.shape.MeshView;
import javafx.scene.shape.TriangleMesh;
import javafx.scene.transform.Rotate;
import javafx.stage.Stage;
public class DeathStar extends Application {

	private static final int DIVISION = 200;
	float radius = 300;

	@Override
	public void start(Stage primaryStage) throws Exception {
		Point3D otherSphere = new Point3D(-radius, 0, -radius * 1.5);
		final TriangleMesh triangleMesh = createMesh(DIVISION, radius, otherSphere);
		MeshView a = new MeshView(triangleMesh);

		a.setTranslateY(radius);
		a.setTranslateX(radius);
		a.setRotationAxis(Rotate.Y_AXIS);
		Scene scene = new Scene(new Group(a));

		

































		primaryStage.setScene(scene);
		primaryStage.show();
	}

	static TriangleMesh createMesh(final int division, final float radius, final Point3D centerOtherSphere) {
		Rotate rotate = new Rotate(180, centerOtherSphere);
		final int div2 = division / 2;

		final int nPoints = division * (div2 - 1) + 2;
		final int nTPoints = (division + 1) * (div2 - 1) + division * 2;
		final int nFaces = division * (div2 - 2) * 2 + division * 2;

		final float rDiv = 1.f / division;

		float points[] = new float[nPoints * 3];
		float tPoints[] = new float[nTPoints * 2];
		int faces[] = new int[nFaces * 6];

		int pPos = 0, tPos = 0;

		for (int y = 0; y < div2 - 1; ++y) {
			float va = rDiv * (y + 1 - div2 / 2) * 2 * (float) Math.PI;
			float sin_va = (float) Math.sin(va);
			float cos_va = (float) Math.cos(va);

			float ty = 0.5f + sin_va * 0.5f;
			for (int i = 0; i < division; ++i) {
				double a = rDiv * i * 2 * (float) Math.PI;
				float hSin = (float) Math.sin(a);
				float hCos = (float) Math.cos(a);
				points[pPos + 0] = hSin * cos_va * radius;
				points[pPos + 2] = hCos * cos_va * radius;
				points[pPos + 1] = sin_va * radius;

				final Point3D point3D = new Point3D(points[pPos + 0], points[pPos + 1], points[pPos + 2]);
				double distance = centerOtherSphere.distance(point3D);
				if (distance <= radius) {
					Point3D subtract = centerOtherSphere.subtract(point3D);
					Point3D transform = rotate.transform(subtract);
					points[pPos + 0] = (float) transform.getX();
					points[pPos + 1] = (float) transform.getY();
					points[pPos + 2] = (float) transform.getZ();
					
				}
				tPoints[tPos + 0] = 1 - rDiv * i;
				tPoints[tPos + 1] = ty;
				pPos += 3;
				tPos += 2;
			}
			tPoints[tPos + 0] = 0;
			tPoints[tPos + 1] = ty;
			tPos += 2;
		}

		points[pPos + 0] = 0;
		points[pPos + 1] = -radius;
		points[pPos + 2] = 0;
		points[pPos + 3] = 0;
		points[pPos + 4] = radius;
		points[pPos + 5] = 0;
		pPos += 6;

		int pS = (div2 - 1) * division;

		float textureDelta = 1.f / 256;
		for (int i = 0; i < division; ++i) {
			tPoints[tPos + 0] = rDiv * (0.5f + i);
			tPoints[tPos + 1] = textureDelta;
			tPos += 2;
		}

		for (int i = 0; i < division; ++i) {
			tPoints[tPos + 0] = rDiv * (0.5f + i);
			tPoints[tPos + 1] = 1 - textureDelta;
			tPos += 2;
		}

		int fIndex = 0;
		for (int y = 0; y < div2 - 2; ++y) {
			for (int x = 0; x < division; ++x) {
				int p0 = y * division + x;
				int p1 = p0 + 1;
				int p2 = p0 + division;
				int p3 = p1 + division;

				int t0 = p0 + y;
				int t1 = t0 + 1;
				int t2 = t0 + division + 1;
				int t3 = t1 + division + 1;

				
				faces[fIndex + 0] = p0;
				faces[fIndex + 1] = t0;
				faces[fIndex + 2] = p1 % division == 0 ? p1 - division : p1;
				faces[fIndex + 3] = t1;
				faces[fIndex + 4] = p2;
				faces[fIndex + 5] = t2;
				fIndex += 6;

				
				faces[fIndex + 0] = p3 % division == 0 ? p3 - division : p3;
				faces[fIndex + 1] = t3;
				faces[fIndex + 2] = p2;
				faces[fIndex + 3] = t2;
				faces[fIndex + 4] = p1 % division == 0 ? p1 - division : p1;
				faces[fIndex + 5] = t1;
				fIndex += 6;
			}
		}

		int p0 = pS;
		int tB = (div2 - 1) * (division + 1);
		for (int x = 0; x < division; ++x) {
			int p2 = x, p1 = x + 1, t0 = tB + x;
			faces[fIndex + 0] = p0;
			faces[fIndex + 1] = t0;
			faces[fIndex + 2] = p1 == division ? 0 : p1;
			faces[fIndex + 3] = p1;
			faces[fIndex + 4] = p2;
			faces[fIndex + 5] = p2;
			fIndex += 6;
		}

		p0 = p0 + 1;
		tB = tB + division;
		int pB = (div2 - 2) * division;

		for (int x = 0; x < division; ++x) {
			int p1 = pB + x, p2 = pB + x + 1, t0 = tB + x;
			int t1 = (div2 - 2) * (division + 1) + x, t2 = t1 + 1;
			faces[fIndex + 0] = p0;
			faces[fIndex + 1] = t0;
			faces[fIndex + 2] = p1;
			faces[fIndex + 3] = t1;
			faces[fIndex + 4] = p2 % division == 0 ? p2 - division : p2;
			faces[fIndex + 5] = t2;
			fIndex += 6;
		}

		TriangleMesh m = new TriangleMesh();
		m.getPoints().setAll(points);
		m.getTexCoords().setAll(tPoints);
		m.getFaces().setAll(faces);

		return m;
	}

	public static void main(String[] args) {

		launch(args);
	}

}



Python: import sys, math, collections

Sphere = collections.namedtuple("Sphere", "cx cy cz r")
V3 = collections.namedtuple("V3", "x y z")

def normalize((x, y, z)):
    len = math.sqrt(x**2 + y**2 + z**2)
    return V3(x / len, y / len, z / len)

def dot(v1, v2):
    d = v1.x*v2.x + v1.y*v2.y + v1.z*v2.z
    return -d if d < 0 else 0.0

def hit_sphere(sph, x0, y0):
    x = x0 - sph.cx
    y = y0 - sph.cy
    zsq = sph.r ** 2 - (x ** 2 + y ** 2)
    if zsq < 0:
        return (False, 0, 0)
    szsq = math.sqrt(zsq)
    return (True, sph.cz - szsq, sph.cz + szsq)

def draw_sphere(k, ambient, light):
    shades = ".:!*oe&
    pos = Sphere(20.0, 20.0, 0.0, 20.0)
    neg = Sphere(1.0, 1.0, -6.0, 20.0)

    for i in xrange(int(math.floor(pos.cy - pos.r)),
                    int(math.ceil(pos.cy + pos.r) + 1)):
        y = i + 0.5
        for j in xrange(int(math.floor(pos.cx - 2 * pos.r)),
                        int(math.ceil(pos.cx + 2 * pos.r) + 1)):
            x = (j - pos.cx) / 2.0 + 0.5 + pos.cx

            (h, zb1, zb2) = hit_sphere(pos, x, y)
            if not h:
                hit_result = 0
            else:
                (h, zs1, zs2) = hit_sphere(neg, x, y)
                if not h:
                    hit_result = 1
                elif zs1 > zb1:
                    hit_result = 1
                elif zs2 > zb2:
                    hit_result = 0
                elif zs2 > zb1:
                    hit_result = 2
                else:
                    hit_result = 1

            if hit_result == 0:
                sys.stdout.write(' ')
                continue
            elif hit_result == 1:
                vec = V3(x - pos.cx, y - pos.cy, zb1 - pos.cz)
            elif hit_result == 2:
                vec = V3(neg.cx-x, neg.cy-y, neg.cz-zs2)
            vec = normalize(vec)

            b = dot(light, vec) ** k + ambient
            intensity = int((1 - b) * len(shades))
            intensity = min(len(shades), max(0, intensity))
            sys.stdout.write(shades[intensity])
        print

light = normalize(V3(-50, 30, 50))
draw_sphere(2, 0.5, light)