Add UE4 filmic tone mapping and make Hable tone mapping configurable.

chunky/src/java/se/llbit/chunky/renderer/postprocessing/HableToneMappingFilter.java

@@ -1,27 +1,144 @@
 package se.llbit.chunky.renderer.postprocessing;
 
+import org.apache.commons.math3.util.FastMath;
+import se.llbit.chunky.renderer.scene.Scene;
+import se.llbit.json.JsonObject;
+import se.llbit.util.Configurable;
+
 /**
- * Implementation of Hable tone mapping
+ * Implementation of Hable (i.e. Uncharted 2) tone mapping
+ *
  * @link http://filmicworlds.com/blog/filmic-tonemapping-operators/
+ * @link https://www.gdcvault.com/play/1012351/Uncharted-2-HDR
  */
-public class HableToneMappingFilter extends SimplePixelPostProcessingFilter {
-  private static final float hA = 0.15f;
-  private static final float hB = 0.50f;
-  private static final float hC = 0.10f;
-  private static final float hD = 0.20f;
-  private static final float hE = 0.02f;
-  private static final float hF = 0.30f;
-  private static final float hW = 11.2f;
-  private static final float whiteScale = 1.0f / (((hW * (hA * hW + hC * hB) + hD * hE) / (hW * (hA * hW + hB) + hD * hF)) - hE / hF);
-
+public class HableToneMappingFilter extends SimplePixelPostProcessingFilter implements Configurable {
+  public enum Preset {
+    /**
+     * Parameters from <a href="http://filmicworlds.com/blog/filmic-tonemapping-operators/">John Hable's blog post</a>
+     */
+    FILMIC_WORLDS,
+
+    /**
+     * Parameters from <a href="https://www.gdcvault.com/play/1012351/Uncharted-2-HDR">John Hable's GDC talk</a>
+     */
+    GDC
+  }
+
+  private float hA;
+  private float hB;
+  private float hC;
+  private float hD;
+  private float hE;
+  private float hF;
+  private float hW;
+  private float whiteScale;
+
+  public HableToneMappingFilter() {
+    reset();
+  }
+
+  private void recalculateWhiteScale() {
+    whiteScale = 1.0f / (((hW * (hA * hW + hC * hB) + hD * hE) / (hW * (hA * hW + hB) + hD * hF)) - hE / hF);
+  }
+
+  public float getShoulderStrength() {
+    return hA;
+  }
+
+  public void setShoulderStrength(float hA) {
+    this.hA = hA;
+    recalculateWhiteScale();
+  }
+
+  public float getLinearStrength() {
+    return hB;
+  }
+
+  public void setLinearStrength(float hB) {
+    this.hB = hB;
+    recalculateWhiteScale();
+  }
+
+  public float getLinearAngle() {
+    return hC;
+  }
+
+  public void setLinearAngle(float hC) {
+    this.hC = hC;
+    recalculateWhiteScale();
+  }
+
+  public float getToeStrength() {
+    return hD;
+  }
+
+  public void setToeStrength(float hD) {
+    this.hD = hD;
+    recalculateWhiteScale();
+  }
+
+  public float getToeNumerator() {
+    return hE;
+  }
+
+  public void setToeNumerator(float hE) {
+    this.hE = hE;
+    recalculateWhiteScale();
+  }
+
+  public float getToeDenominator() {
+    return hF;
+  }
+
+  public void setToeDenominator(float hF) {
+    this.hF = hF;
+    recalculateWhiteScale();
+  }
+
+  public float getLinearWhitePointValue() {
+    return hW;
+  }
+
+  public void setLinearWhitePointValue(float hW) {
+    this.hW = hW;
+    recalculateWhiteScale();
+  }
+
+  public void reset() {
+    applyPreset(Preset.FILMIC_WORLDS);
+  }
+
+  public void applyPreset(Preset preset) {
+    switch (preset) {
+      case FILMIC_WORLDS:
+        hA = 0.15f;
+        hB = 0.50f;
+        hC = 0.10f;
+        hD = 0.20f;
+        hE = 0.02f;
+        hF = 0.30f;
+        hW = 11.2f;
+        break;
+      case GDC:
+        hA = 0.22f;
+        hB = 0.30f;
+        hC = 0.10f;
+        hD = 0.20f;
+        hE = 0.01f;
+        hF = 0.30f;
+        hW = 11.2f;
+        break;
+    }
+    recalculateWhiteScale();
+  }
+
   @Override
   public void processPixel(double[] pixel) {
-    // This adjusts the exposure by a factor of 16 so that the resulting exposure approximately matches the other
-    // post-processing methods. Without this, the image would be very dark.
-    for(int i = 0; i < 3; ++i) {
-      pixel[i] *= 16;
+    for (int i = 0; i < 3; ++i) {
+      pixel[i] *= 2; // exposure bias
       pixel[i] = ((pixel[i] * (hA * pixel[i] + hC * hB) + hD * hE) / (pixel[i] * (hA * pixel[i] + hB) + hD * hF)) - hE / hF;
       pixel[i] *= whiteScale;
+      pixel[i] = FastMath.pow(pixel[i], 1 / Scene.DEFAULT_GAMMA);
     }
   }
 
@@ -34,4 +151,28 @@ public String getName() {
   public String getId() {
     return "TONEMAP3";
   }
+
+  @Override
+  public void loadConfiguration(JsonObject json) {
+    reset();
+    hA = json.get("shoulderStrength").floatValue(hA);
+    hB = json.get("linearStrength").floatValue(hB);
+    hC = json.get("linearAngle").floatValue(hC);
+    hD = json.get("toeStrength").floatValue(hD);
+    hE = json.get("toeNumerator").floatValue(hE);
+    hF = json.get("toeDenominator").floatValue(hF);
+    hW = json.get("linearWhitePointValue").floatValue(hW);
+    recalculateWhiteScale();
+  }
+
+  @Override
+  public void storeConfiguration(JsonObject json) {
+    json.add("shoulderStrength", hA);
+    json.add("linearStrength", hB);
+    json.add("linearAngle", hC);
+    json.add("toeStrength", hD);
+    json.add("toeNumerator", hE);
+    json.add("toeDenominator", hF);
+    json.add("linearWhitePointValue", hW);
+  }
 }

chunky/src/java/se/llbit/chunky/renderer/postprocessing/PostProcessingFilter.java

@@ -2,6 +2,7 @@
 
 import se.llbit.chunky.plugin.PluginApi;
 import se.llbit.chunky.resources.BitmapImage;
+import se.llbit.util.Registerable;
 import se.llbit.util.TaskTracker;
 
 /**
@@ -14,7 +15,7 @@
  * PixelPostProcessingFilter} instead.
  */
 @PluginApi
-public interface PostProcessingFilter {
+public interface PostProcessingFilter extends Registerable {
   /**
    * Post process the entire frame
    * @param width The width of the image
@@ -26,23 +27,12 @@ public interface PostProcessingFilter {
    */
   void processFrame(int width, int height, double[] input, BitmapImage output, double exposure, TaskTracker.Task task);
 
-  /**
-   * Get name of the post processing filter
-   * @return The name of the post processing filter
-   */
-  String getName();
-
   /**
    * Get description of the post processing filter
    * @return The description of the post processing filter
    */
+  @Override
   default String getDescription() {
     return null;
   }
-
-  /**
-   * Get id of the post processing filter
-   * @return The id of the post processing filter
-   */
-  String getId();
 }

chunky/src/java/se/llbit/chunky/renderer/postprocessing/PostProcessingFilters.java

@@ -18,6 +18,7 @@ public abstract class PostProcessingFilters {
     addPostProcessingFilter(new Tonemap1Filter());
     addPostProcessingFilter(new ACESFilmicFilter());
     addPostProcessingFilter(new HableToneMappingFilter());
+    addPostProcessingFilter(new UE4ToneMappingFilter());
   }
 
   public static Optional<PostProcessingFilter> getPostProcessingFilterFromId(String id) {