Add readme, images, ppm2png convertor

README.md

@@ -0,0 +1,7 @@
+# Simple ray tracer
+## Build and run
+`mvn clean package`\
+`java -jar ray-tracer.jar`
+
+### 4K rendered scene
+![4K rendered scene](pictures/image-4k.png)

pom.xml

@@ -16,6 +16,11 @@
 
     <build>
         <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>3.0.0-M5</version>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>

src/main/java/Convertor.java

@@ -0,0 +1,86 @@
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+
+public class Convertor {
+    public static void main(String[] args) {
+
+        final String sourceFilename = "image.ppm";
+        final String destFilename = "image.png";
+
+        // try to get hold of the file.
+        try(BufferedReader reader = new BufferedReader(new FileReader(sourceFilename))) {
+            // validate file header
+            final String FileHeader = "P3";
+            String line = reader.readLine();
+            if (!FileHeader.equals(line)) {
+                System.err.printf("Failed to read %s, bad header\n", sourceFilename);
+                System.exit(1);
+            }
+
+            int width = 0;
+            int height = 0;
+
+            line = reader.readLine();
+            if (line != null) {
+                String[] values = line.split(" ");
+                width = Integer.parseInt(values[0]);
+                height = Integer.parseInt(values[1]);
+            } else {
+                System.err.printf("Failed to read %s, bad dimensions\n", sourceFilename);
+                System.exit(1);
+            }
+
+
+            // just validate the bpp value, even though it isn't being used
+            line = reader.readLine();
+            if (line != null) {
+                int bpp = Integer.parseInt(line);
+                if (bpp < 0 || bpp > 255) {
+                    System.err.printf("Failed to read %s, bad colour size\n", sourceFilename);
+                    System.exit(1);
+                }
+            } else {
+                System.err.printf("Failed to read %s, bad colour size\n", sourceFilename);
+                System.exit(1);
+            }
+
+            // prepare the data buffer
+            final int BPP = 3;
+            int imageSize = width * height;
+            System.out.println(width + "x" + height);
+            var imageData = new int[imageSize];
+
+            int row = 0;
+            while ((line = reader.readLine()) != null) {
+                String[] values = line.split(" ");
+                if (values.length != BPP) {
+                    System.err.printf("Failed to read %s at line %d, bad colour size", sourceFilename, row);
+                    System.exit(1);
+                }
+
+                int r = Integer.parseInt(values[0]);
+                int g = Integer.parseInt(values[1]);
+                int b = Integer.parseInt(values[2]);
+
+                int pixelValue = (r << 16) | (g << 8) | b;
+                imageData[row++] = pixelValue;
+            }
+
+            var bufferImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
+            bufferImg.setRGB(0, 0, width, height, imageData, 0, width);
+
+            var outputfile = new File(destFilename);
+            ImageIO.write(bufferImg, "png", outputfile);
+        } catch (IOException ex) {
+            System.out.println(ex.getMessage());
+            ex.printStackTrace();
+            System.exit(1);
+        }
+
+        System.out.printf("Processed %s into %s\n", sourceFilename, destFilename);
+    }
+}

src/main/java/Main.java

@@ -36,32 +36,31 @@ public static void main(String[] args) throws Exception{
     public Main(BufferedWriter writer) throws IOException {
         //Image
         double aspectRatio = 16.0/9.0;
-        int width = 3840;
+        int width = 400;
         int height = (int)(width / aspectRatio);
-        int samplesPerPixel = 500;
+        int samplesPerPixel = 100;
         int depth = 50;
         //World
         HittableList world = new HittableArrayList();
 
         Material ground = new Lambertian(new Color(0.5, 0.5, 0.5));
         Material left = new Lambertian(new Color(0, 0, 1));
         Material center = new Metal(new Color(0.8, 0.6, 0.2));
-        Material right = new Dielectric(2.4);
+        Material right = new Dielectric(1.5);
 
         world.add(new Sphere(new Point(0, -1000, 0), 1000, ground));
 
-        world.add(new Sphere(new Point(-1.5, 1, 0), 1, left));
+        world.add(new Sphere(new Point(-2, 1, 0), 1, left));
         world.add(new Sphere(new Point(0, 1, 0), 1, center));
-        world.add(new Sphere(new Point(1.5, 1, 0), 1, right));
-        Util.fillScene(world);
+        world.add(new Sphere(new Point(2, 1, 0), 1, right));
+//        Util.fillScene(world);
         //Camera
-        Point lookFrom = new Point(13, 3, 13);
-        Point lookAt = new Point();
+        Point lookFrom = new Point(5, 5, 13);
+        Point lookAt = new Point(0, 1, 0);
         Vector worldNormal = new Vector(0, 1, 0);
         double fov = 20;
         double aperture = 0.1;
-        double focusDist = new Vector(lookAt, lookAt).length();
-
+        double focusDist = new Vector(lookAt, lookFrom).length();
 
         Camera camera = new ClearCamera(lookFrom, lookAt, worldNormal, fov, aspectRatio);
 //        Camera camera = new BlurCamera(lookFrom, lookAt, worldNormal, fov, aspectRatio, aperture, focusDist);
@@ -78,10 +77,10 @@ public Main(BufferedWriter writer) throws IOException {
                     double v = ((double) j + random.nextDouble())/(height - 1);
                     Ray ray = camera.getRay(u, v);
                     Color color = rayColor(ray, world, depth).scale(1d/samplesPerPixel);
+//                    Color color = Util.normalColor(ray, world).scale(1d/samplesPerPixel);
                     pixelColor.setRed(pixelColor.getRed() + color.getRed())
                             .setGreen(pixelColor.getGreen() + color.getGreen())
                             .setBlue(pixelColor.getBlue() + color.getBlue());
-
                 }
                 writeColor(writer, pixelColor, Math::sqrt);
             }
@@ -118,7 +117,6 @@ private void writeColor(BufferedWriter writer, Color color, Function<Double, Dou
         double r = gammaCorrectionFunction.apply(color.getRed());
         double g = gammaCorrectionFunction.apply(color.getGreen());
         double b = gammaCorrectionFunction.apply(color.getBlue());
-
         writer.write((int)(256 * clamp(r, 0d, 0.999)) + " " + (int)(256 * clamp(g, 0d, 0.999)) + " " + (int)(256 * clamp(b, 0d, 0.999)) + '\n');
     }
 

src/main/java/util/Util.java

@@ -21,7 +21,7 @@ public static double clamp(double x, double min, double max){
     /**
      * Represents normal of hit point, as a color
      */
-    private Color normalColor(Ray r, Hittable world){
+    public static Color normalColor(Ray r, Hittable world){
         HitRecord record = new HitRecord();
 
         if(world.hit(r, 0,  Double.POSITIVE_INFINITY, record)){