Add option to disable "fancier translucency" (#1615)

* add toggle for "fancier translucency"

* small UI fix

Author: JustinTimeCuber

chunky/src/java/se/llbit/chunky/renderer/scene/PathTracer.java

@@ -104,7 +104,7 @@ public static boolean pathTrace(Scene scene, Ray ray, WorkerState state, int add
 
       float pSpecular = currentMat.specular;
 
-      double pDiffuse = 1 - Math.sqrt(1 - ray.color.w);
+      double pDiffuse = scene.fancierTranslucency ? 1 - Math.sqrt(1 - ray.color.w) : ray.color.w;
 
       float n1 = prevMat.ior;
       float n2 = currentMat.ior;
@@ -425,50 +425,57 @@ private static boolean doTransmission(Ray ray, Ray next, Vector4 cumulativeColor
   }
 
   private static void translucentRayColor(Scene scene, Ray ray, Ray next, Vector4 cumulativeColor, double opacity) {
-    // Color-based transmission value
-    double colorTrans = (ray.color.x + ray.color.y + ray.color.z)/3;
-    // Total amount of light we want to transmit (overall transparency of texture)
-    double shouldTrans = 1 - opacity;
-    // Amount of each color to transmit - default to overall transparency if RGB values add to 0 (e.g. regular glass)
-    Vector3 rgbTrans = new Vector3(shouldTrans, shouldTrans, shouldTrans);
-    if(colorTrans > 0) {
-      // Amount to transmit of each color is scaled so the total transmitted amount matches the texture's transparency
-      rgbTrans.set(ray.color.toVec3());
-      rgbTrans.scale(shouldTrans / colorTrans);
-    }
-    double transmissivityCap = scene.transmissivityCap;
-    // Determine the color with the highest transmissivity
-    double maxTrans = Math.max(rgbTrans.x, Math.max(rgbTrans.y, rgbTrans.z));
-    if(maxTrans > transmissivityCap) {
-      if (maxTrans == rgbTrans.x) {
-        // Give excess transmission from red to green and blue
-        double gTransNew = reassignTransmissivity(rgbTrans.x, rgbTrans.y, rgbTrans.z, shouldTrans, transmissivityCap);
-        rgbTrans.z = reassignTransmissivity(rgbTrans.x, rgbTrans.z, rgbTrans.y, shouldTrans, transmissivityCap);
-        rgbTrans.y = gTransNew;
-        rgbTrans.x = transmissivityCap;
-      } else if (maxTrans == rgbTrans.y) {
-        // Give excess transmission from green to red and blue
-        double rTransNew = reassignTransmissivity(rgbTrans.y, rgbTrans.x, rgbTrans.z, shouldTrans, transmissivityCap);
-        rgbTrans.z = reassignTransmissivity(rgbTrans.y, rgbTrans.z, rgbTrans.x, shouldTrans, transmissivityCap);
-        rgbTrans.x = rTransNew;
-        rgbTrans.y = transmissivityCap;
-      } else if (maxTrans == rgbTrans.z) {
-        // Give excess transmission from blue to green and red
-        double gTransNew = reassignTransmissivity(rgbTrans.z, rgbTrans.y, rgbTrans.x, shouldTrans, transmissivityCap);
-        rgbTrans.x = reassignTransmissivity(rgbTrans.z, rgbTrans.x, rgbTrans.y, shouldTrans, transmissivityCap);
-        rgbTrans.y = gTransNew;
-        rgbTrans.z = transmissivityCap;
+    Vector3 rgbTrans;
+    if(scene.fancierTranslucency) {
+      // Color-based transmission value
+      double colorTrans = (ray.color.x + ray.color.y + ray.color.z) / 3;
+      // Total amount of light we want to transmit (overall transparency of texture)
+      double shouldTrans = 1 - opacity;
+      // Amount of each color to transmit - default to overall transparency if RGB values add to 0 (e.g. regular glass)
+      rgbTrans = new Vector3(shouldTrans, shouldTrans, shouldTrans);
+      if (colorTrans > 0) {
+        // Amount to transmit of each color is scaled so the total transmitted amount matches the texture's transparency
+        rgbTrans.set(ray.color.toVec3());
+        rgbTrans.scale(shouldTrans / colorTrans);
       }
-    }
-    // Don't need to check for energy gain if transmissivity cap is 1
-    if(transmissivityCap > 1) {
-      double currentEnergy = rgbTrans.x * next.color.x + rgbTrans.y * next.color.y + rgbTrans.z * next.color.z;
-      double nextEnergy = next.color.x + next.color.y + next.color.z;
-      double energyRatio = nextEnergy / currentEnergy;
-      // Normalize if there is net energy gain across all channels (more likely for higher transmissivityCap combined with high-saturation light source)
-      if(energyRatio < 1) {
-        rgbTrans.scale(energyRatio);
+      double transmissivityCap = scene.transmissivityCap;
+      // Determine the color with the highest transmissivity
+      double maxTrans = Math.max(rgbTrans.x, Math.max(rgbTrans.y, rgbTrans.z));
+      if (maxTrans > transmissivityCap) {
+        if (maxTrans == rgbTrans.x) {
+          // Give excess transmission from red to green and blue
+          double gTransNew = reassignTransmissivity(rgbTrans.x, rgbTrans.y, rgbTrans.z, shouldTrans, transmissivityCap);
+          rgbTrans.z = reassignTransmissivity(rgbTrans.x, rgbTrans.z, rgbTrans.y, shouldTrans, transmissivityCap);
+          rgbTrans.y = gTransNew;
+          rgbTrans.x = transmissivityCap;
+        } else if (maxTrans == rgbTrans.y) {
+          // Give excess transmission from green to red and blue
+          double rTransNew = reassignTransmissivity(rgbTrans.y, rgbTrans.x, rgbTrans.z, shouldTrans, transmissivityCap);
+          rgbTrans.z = reassignTransmissivity(rgbTrans.y, rgbTrans.z, rgbTrans.x, shouldTrans, transmissivityCap);
+          rgbTrans.x = rTransNew;
+          rgbTrans.y = transmissivityCap;
+        } else if (maxTrans == rgbTrans.z) {
+          // Give excess transmission from blue to green and red
+          double gTransNew = reassignTransmissivity(rgbTrans.z, rgbTrans.y, rgbTrans.x, shouldTrans, transmissivityCap);
+          rgbTrans.x = reassignTransmissivity(rgbTrans.z, rgbTrans.x, rgbTrans.y, shouldTrans, transmissivityCap);
+          rgbTrans.y = gTransNew;
+          rgbTrans.z = transmissivityCap;
+        }
       }
+      // Don't need to check for energy gain if transmissivity cap is 1
+      if (transmissivityCap > 1) {
+        double currentEnergy = rgbTrans.x * next.color.x + rgbTrans.y * next.color.y + rgbTrans.z * next.color.z;
+        double nextEnergy = next.color.x + next.color.y + next.color.z;
+        double energyRatio = nextEnergy / currentEnergy;
+        // Normalize if there is net energy gain across all channels (more likely for higher transmissivityCap combined with high-saturation light source)
+        if (energyRatio < 1) {
+          rgbTrans.scale(energyRatio);
+        }
+      }
+    } else {
+      // Old method (see https://github.com/chunky-dev/chunky/pull/1513)
+      rgbTrans = new Vector3(1 - opacity, 1 - opacity, 1 - opacity);
+      rgbTrans.scaleAdd(opacity, ray.color.toVec3());
     }
     // Scale color based on next ray
     Vector4 outputColor = new Vector4(0, 0, 0, 0);

chunky/src/java/se/llbit/chunky/renderer/scene/Scene.java

@@ -211,6 +211,7 @@ public class Scene implements JsonSerializable, Refreshable {
   protected boolean emittersEnabled = DEFAULT_EMITTERS_ENABLED;
   protected double emitterIntensity = DEFAULT_EMITTER_INTENSITY;
   protected EmitterSamplingStrategy emitterSamplingStrategy = EmitterSamplingStrategy.NONE;
+  protected boolean fancierTranslucency = true;
   protected double transmissivityCap = DEFAULT_TRANSMISSIVITY_CAP;
 
   protected SunSamplingStrategy sunSamplingStrategy = SunSamplingStrategy.FAST;
@@ -451,6 +452,7 @@ public synchronized void copyState(Scene other, boolean copyChunks) {
     emitterIntensity = other.emitterIntensity;
     emitterSamplingStrategy = other.emitterSamplingStrategy;
     preventNormalEmitterWithSampling = other.preventNormalEmitterWithSampling;
+    fancierTranslucency = other.fancierTranslucency;
     transmissivityCap = other.transmissivityCap;
     transparentSky = other.transparentSky;
     yClipMin = other.yClipMin;
@@ -2643,6 +2645,7 @@ public void setUseCustomWaterColor(boolean value) {
     json.add("saveSnapshots", saveSnapshots);
     json.add("emittersEnabled", emittersEnabled);
     json.add("emitterIntensity", emitterIntensity);
+    json.add("fancierTranslucency", fancierTranslucency);
     json.add("transmissivityCap", transmissivityCap);
     json.add("sunSamplingStrategy", sunSamplingStrategy.getId());
     json.add("stillWater", stillWater);
@@ -2902,6 +2905,7 @@ public synchronized void importFromJson(JsonObject json) {
     saveSnapshots = json.get("saveSnapshots").boolValue(saveSnapshots);
     emittersEnabled = json.get("emittersEnabled").boolValue(emittersEnabled);
     emitterIntensity = json.get("emitterIntensity").doubleValue(emitterIntensity);
+    fancierTranslucency = json.get("fancierTranslucency").boolValue(fancierTranslucency);
     transmissivityCap = json.get("transmissivityCap").doubleValue(transmissivityCap);
 
     if (json.get("sunSamplingStrategy").isUnknown()) {
@@ -3410,6 +3414,14 @@ public boolean getHideUnknownBlocks() {
   public void setHideUnknownBlocks(boolean hideUnknownBlocks) {
     this.hideUnknownBlocks = hideUnknownBlocks;
   }
+  public boolean getFancierTranslucency() {
+    return fancierTranslucency;
+  }
+
+  public void setFancierTranslucency(boolean value) {
+    fancierTranslucency = value;
+    refresh();
+  }
 
   public double getTransmissivityCap() {
     return transmissivityCap;

chunky/src/java/se/llbit/chunky/ui/render/tabs/AdvancedTab.java

@@ -68,6 +68,7 @@ public class AdvancedTab extends ScrollPane implements RenderControlsTab, Initia
   @FXML private Button mergeRenderDump;
   @FXML private CheckBox shutdown;
   @FXML private CheckBox fastFog;
+  @FXML private CheckBox fancierTranslucency;
   @FXML private DoubleAdjuster transmissivityCap;
   @FXML private IntegerAdjuster cacheResolution;
   @FXML private DoubleAdjuster animationTime;
@@ -155,6 +156,16 @@ public PictureExportFormat fromString(String string) {
     fastFog.setTooltip(new Tooltip("Enable faster fog rendering algorithm."));
     fastFog.selectedProperty()
             .addListener((observable, oldValue, newValue) -> scene.setFastFog(newValue));
+    fancierTranslucency.setTooltip(new Tooltip("Enable more sophisticated algorithm for computing color changes through translucent materials."));
+    fancierTranslucency.selectedProperty()
+      .addListener((observable, oldValue, newValue) -> {
+        scene.setFancierTranslucency(newValue);
+        transmissivityCap.setVisible(newValue);
+        transmissivityCap.setManaged(newValue);
+      });
+    boolean tcapVisible = scene != null && scene.getFancierTranslucency();
+    transmissivityCap.setVisible(tcapVisible);
+    transmissivityCap.setManaged(tcapVisible);
     transmissivityCap.setName("Transmissivity cap");
     transmissivityCap.setRange(Scene.MIN_TRANSMISSIVITY_CAP, Scene.MAX_TRANSMISSIVITY_CAP);
     transmissivityCap.clampBoth();
@@ -322,6 +333,7 @@ public boolean shutdownAfterCompletedRender() {
   public void update(Scene scene) {
     outputMode.getSelectionModel().select(scene.getOutputMode());
     fastFog.setSelected(scene.fog.fastFog());
+    fancierTranslucency.setSelected(scene.getFancierTranslucency());
     transmissivityCap.set(scene.getTransmissivityCap());
     renderThreads.set(PersistentSettings.getNumThreads());
     cpuLoad.set(PersistentSettings.getCPULoad());

chunky/src/res/se/llbit/chunky/ui/render/tabs/AdvancedTab.fxml

@@ -24,6 +24,7 @@
     <Separator prefWidth="200.0" />
     <CheckBox fx:id="shutdown" mnemonicParsing="false" text="Shutdown computer when render completes" />
     <CheckBox fx:id="fastFog" mnemonicParsing="false" text="Fast fog" />
+    <CheckBox fx:id="fancierTranslucency" mnemonicParsing="false" text="Fancier translucency" />
     <DoubleAdjuster fx:id="transmissivityCap" />
     <IntegerAdjuster fx:id="cacheResolution" />
     <DoubleAdjuster fx:id="animationTime" />