From 9d90dc24b9619d734fa3238342752b344d6a62ef Mon Sep 17 00:00:00 2001
From: Riccardo Balbo <os@rblb.it>
Date: Tue, 5 Aug 2025 19:10:53 +0200
Subject: [PATCH 1/4] add support for global lights

---
 .../java/com/jme3/light/DirectionalLight.java | 36 ++++++++
 .../src/main/java/com/jme3/light/Light.java   | 23 +++++
 .../main/java/com/jme3/light/LightList.java   | 50 ++++++++--
 .../main/java/com/jme3/light/PointLight.java  | 61 +++++++++++++
 .../main/java/com/jme3/light/SpotLight.java   | 91 +++++++++++++++++++
 .../src/main/java/com/jme3/scene/Node.java    | 19 ++++
 .../src/main/java/com/jme3/scene/Spatial.java | 21 ++++-
 .../gltf/LightsPunctualExtensionLoader.java   |  6 +-
 8 files changed, 291 insertions(+), 16 deletions(-)

diff --git a/jme3-core/src/main/java/com/jme3/light/DirectionalLight.java b/jme3-core/src/main/java/com/jme3/light/DirectionalLight.java
index ba142071f4..2d71d322a3 100644
--- a/jme3-core/src/main/java/com/jme3/light/DirectionalLight.java
+++ b/jme3-core/src/main/java/com/jme3/light/DirectionalLight.java
@@ -59,6 +59,17 @@ public class DirectionalLight extends Light {
      * Creates a DirectionalLight
      */
     public DirectionalLight() {
+        super();
+    }
+
+    /**
+     * Creates a DirectionalLight
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.     
+     */
+    public DirectionalLight(boolean global) {
+        this();
+        this.global = global;
     }
 
     /**
@@ -66,9 +77,21 @@ public DirectionalLight() {
      * @param direction the light's direction
      */
     public DirectionalLight(Vector3f direction) {
+        super();
         setDirection(direction);
     }
 
+    /**
+     * Creates a DirectionalLight with the given direction
+     * @param direction the light's direction
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     */
+    public DirectionalLight(Vector3f direction, boolean global) {
+        this(direction);
+        this.global = global;
+    }
+
     /**
      * Creates a DirectionalLight with the given direction and the given color
      * @param direction the light's direction
@@ -79,6 +102,19 @@ public DirectionalLight(Vector3f direction, ColorRGBA color) {
         setDirection(direction);
     }
 
+    /**
+     * Creates a DirectionalLight with the given direction and the given color
+     * @param direction the light's direction
+     * @param color the light's color
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     */
+    public DirectionalLight(Vector3f direction, ColorRGBA color, boolean global) {
+        this(direction, color);
+        this.global = global;
+    }
+
+
     @Override
     public void computeLastDistance(Spatial owner) {
         // directional lights are after ambient lights
diff --git a/jme3-core/src/main/java/com/jme3/light/Light.java b/jme3-core/src/main/java/com/jme3/light/Light.java
index cebb4ae2a0..4694243822 100644
--- a/jme3-core/src/main/java/com/jme3/light/Light.java
+++ b/jme3-core/src/main/java/com/jme3/light/Light.java
@@ -116,6 +116,7 @@ public int getId(){
      * The light name. 
      */
     protected String name;
+    protected boolean global = false;
     
     boolean frustumCheckNeeded = true;
     boolean intersectsFrustum  = false;
@@ -123,10 +124,30 @@ public int getId(){
     protected Light() {
     }
 
+
+    protected Light(boolean global) {
+        this.global = global;
+    }
+    
+    protected Light(ColorRGBA color, boolean global) {
+        setColor(color);
+    }
+
     protected Light(ColorRGBA color) {
         setColor(color);
     }
 
+
+    /**
+     * Returns true if this light affects the entire tree from the root node,
+     * otherwise returns false, meaning it only affects the children of the node
+     * in which it is attached.
+     * @return true if the light is global, otherwise false.
+     */
+    public boolean isGlobal() {
+        return global;
+    }
+
     /**
      * Returns the color of the light.
      * 
@@ -265,6 +286,7 @@ public void write(JmeExporter ex) throws IOException {
         oc.write(color, "color", null);
         oc.write(enabled, "enabled", true);
         oc.write(name, "name", null);
+        oc.write(global, "global", false);
     }
 
     @Override
@@ -273,6 +295,7 @@ public void read(JmeImporter im) throws IOException {
         color = (ColorRGBA) ic.readSavable("color", null);
         enabled = ic.readBoolean("enabled", true);
         name = ic.readString("name", null);
+        global = ic.readBoolean("global", false);
     }
 
     /**
diff --git a/jme3-core/src/main/java/com/jme3/light/LightList.java b/jme3-core/src/main/java/com/jme3/light/LightList.java
index 97c4c29820..d6179dd986 100644
--- a/jme3-core/src/main/java/com/jme3/light/LightList.java
+++ b/jme3-core/src/main/java/com/jme3/light/LightList.java
@@ -38,6 +38,7 @@
 import com.jme3.util.SortUtil;
 import java.io.IOException;
 import java.util.*;
+import java.util.function.Predicate;
 
 /**
  * <code>LightList</code> is used internally by {@link Spatial}s to manage
@@ -230,6 +231,20 @@ public void sort(boolean transformChanged) {
      * @param parent the parent's world-space LightList
      */
     public void update(LightList local, LightList parent) {
+        update(local, parent, null);
+    }
+
+
+    /**
+     * Updates a "world-space" light list, using the spatial's local-space
+     * light list, its parent's world-space light list and an optional filter.
+     *
+     * @param local the local-space LightList (not null)
+     * @param parent the parent's world-space LightList
+     * @param filter an optional filter to apply to the lights
+     *               (null means no filtering)
+     */
+    public void update(LightList local, LightList parent, Predicate<Light> filter) {
         // clear the list as it will be reconstructed
         // using the arguments
         clear();
@@ -237,30 +252,32 @@ public void update(LightList local, LightList parent) {
         while (list.length <= local.listSize) {
             doubleSize();
         }
-
-        // add the lights from the local list
-        System.arraycopy(local.list, 0, list, 0, local.listSize);
-        for (int i = 0; i < local.listSize; i++) {
-//            list[i] = local.list[i];
-            distToOwner[i] = Float.NEGATIVE_INFINITY;
+        
+        int localListSize = 0;// local.listSize;
+        for(int i=0;i<local.listSize;i++){
+            Light l = local.list[i];
+            if (filter != null && !filter.test(l))  continue; 
+            list[localListSize] = l;
+            distToOwner[localListSize] = Float.NEGATIVE_INFINITY;
+            localListSize++;
         }
 
         // if the spatial has a parent node, add the lights
         // from the parent list as well
         if (parent != null) {
-            int sz = local.listSize + parent.listSize;
+            int sz = localListSize + parent.listSize;
             while (list.length <= sz)
                 doubleSize();
 
             for (int i = 0; i < parent.listSize; i++) {
-                int p = i + local.listSize;
+                int p = i + localListSize;
                 list[p] = parent.list[i];
                 distToOwner[p] = Float.NEGATIVE_INFINITY;
             }
 
-            listSize = local.listSize + parent.listSize;
+            listSize = localListSize + parent.listSize;
         } else {
-            listSize = local.listSize;
+            listSize = localListSize;
         }
     }
 
@@ -361,4 +378,17 @@ public void read(JmeImporter im) throws IOException {
 
         Arrays.fill(distToOwner, Float.NEGATIVE_INFINITY);
     }
+
+    @Override
+    public String toString() {
+        StringBuilder sb = new StringBuilder("LightList[");
+        for (int i = 0; i < listSize; i++) {
+            sb.append(list[i]);
+            if (i < listSize - 1) {
+                sb.append(", ");
+            }
+        }
+        sb.append("]");
+        return sb.toString();
+    }
 }
diff --git a/jme3-core/src/main/java/com/jme3/light/PointLight.java b/jme3-core/src/main/java/com/jme3/light/PointLight.java
index 440a45a740..df596317c5 100644
--- a/jme3-core/src/main/java/com/jme3/light/PointLight.java
+++ b/jme3-core/src/main/java/com/jme3/light/PointLight.java
@@ -66,6 +66,17 @@ public class PointLight extends Light {
      * Creates a PointLight
      */
     public PointLight() {
+        super();
+    }
+
+    /**
+     * Creates a PointLight
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     */
+    public PointLight(boolean global) {
+        this();
+        this.global = global;
     }
 
     /**
@@ -73,8 +84,20 @@ public PointLight() {
      * @param position the position in world space
      */
     public PointLight(Vector3f position) {
+        super();
         setPosition(position);
     }
+    
+    /**
+     * Creates a PointLight at the given position
+     * @param position the position in world space
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     */
+    public PointLight(Vector3f position, boolean global) {
+        this(position);
+        this.global = global;
+    }
 
     /**
      * Creates a PointLight at the given position and with the given color
@@ -86,6 +109,18 @@ public PointLight(Vector3f position, ColorRGBA color) {
         setPosition(position);
     }
 
+    /**
+     * Creates a PointLight at the given position and with the given color
+     * @param position the position in world space
+     * @param color the light color
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     */
+    public PointLight(Vector3f position, ColorRGBA color, boolean global) {
+        this(position, color);
+        this.global = global;
+    }
+
     /**
      * Creates a PointLight at the given position, with the given color and the
      * given radius
@@ -97,6 +132,20 @@ public PointLight(Vector3f position, ColorRGBA color, float radius) {
         this(position, color);
         setRadius(radius);
     }
+    
+    /**
+     * Creates a PointLight at the given position, with the given color and the
+     * given radius
+     * @param position the position in world space
+     * @param color the light color
+     * @param radius the light radius
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     */
+    public PointLight(Vector3f position, ColorRGBA color, float radius, boolean global) {
+        this(position, color, radius);
+        this.global = global;
+    }
 
     /**
      * Creates a PointLight at the given position, with the given radius
@@ -107,6 +156,18 @@ public PointLight(Vector3f position, float radius) {
         this(position);
         setRadius(radius);
     }
+    
+    /**
+     * Creates a PointLight at the given position, with the given radius
+     * @param position the position in world space
+     * @param radius the light radius
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     */
+    public PointLight(Vector3f position, float radius, boolean global) {
+        this(position, radius);
+        this.global = global;
+    }
 
     @Override
     public void computeLastDistance(Spatial owner) {
diff --git a/jme3-core/src/main/java/com/jme3/light/SpotLight.java b/jme3-core/src/main/java/com/jme3/light/SpotLight.java
index e122fe2cbc..e19ec05268 100644
--- a/jme3-core/src/main/java/com/jme3/light/SpotLight.java
+++ b/jme3-core/src/main/java/com/jme3/light/SpotLight.java
@@ -80,6 +80,17 @@ public SpotLight() {
         computeAngleParameters();
     }
 
+        
+    /**
+     * Creates a SpotLight.
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     */
+    public SpotLight(boolean global) {
+        this();
+        this.global = global;
+    }
+
     /**
      * Creates a SpotLight at the given position and with the given direction.
      * @param position the position in world space.
@@ -90,6 +101,18 @@ public SpotLight(Vector3f position, Vector3f direction) {
         setPosition(position);
         setDirection(direction);
     }
+
+     /**
+     * Creates a SpotLight at the given position and with the given direction.
+     * @param position the position in world space.
+     * @param direction the direction of the light.
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     */
+    public SpotLight(Vector3f position, Vector3f direction, boolean global) {
+        this(position, direction);
+        this.global = global;
+    }
     
     /**
      * Creates a SpotLight at the given position, with the given direction, and the
@@ -105,6 +128,20 @@ public SpotLight(Vector3f position, Vector3f direction, float range) {
         setSpotRange(range);
     }
 
+     /**
+     * Creates a SpotLight at the given position, with the given direction, and the
+     * given range.
+     * @param position the position in world space.
+     * @param direction the direction of the light.
+     * @param range the spotlight range
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     */
+    public SpotLight(Vector3f position, Vector3f direction, float range, boolean global) {
+        this(position, direction, range);
+        this.global = global;
+    }
+
     /**
      * Creates a SpotLight at the given position, with the given direction and
      * the given color.
@@ -119,6 +156,21 @@ public SpotLight(Vector3f position, Vector3f direction, ColorRGBA color) {
         setDirection(direction);
     }
 
+
+    /**
+     * Creates a SpotLight at the given position, with the given direction and
+     * the given color.
+     * @param position the position in world space.
+     * @param direction the direction of the light.
+     * @param color the light's color.
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     */
+    public SpotLight(Vector3f position, Vector3f direction, ColorRGBA color, boolean global) {
+        this(position, direction, color);
+        this.global = global;
+    }
+
     /**
      * Creates a SpotLight at the given position, with the given direction,
      * the given range and the given color.
@@ -134,6 +186,22 @@ public SpotLight(Vector3f position, Vector3f direction, float range, ColorRGBA c
         setDirection(direction);
         setSpotRange(range);
     }
+
+    /**
+     * Creates a SpotLight at the given position, with the given direction,
+     * the given range and the given color.
+     * @param position the position in world space.
+     * @param direction the direction of the light.
+     * @param range the spotlight range
+     * @param color the light's color.
+     */
+    public SpotLight(Vector3f position, Vector3f direction, float range, ColorRGBA color, boolean global) {
+        this(position, direction, range, color);
+        this.global = global;
+    }
+    
+    
+    
     
     /**
      * Creates a SpotLight at the given position, with the given direction,
@@ -160,6 +228,29 @@ public SpotLight(Vector3f position, Vector3f direction, float range, ColorRGBA c
         setSpotRange(range);
     }  
 
+    /**
+     * Creates a SpotLight at the given position, with the given direction,
+     * the given color and the given inner and outer angles 
+     * (controls the falloff of the light)
+     * 
+     * @param position the position in world space.
+     * @param direction the direction of the light.
+     * @param range the spotlight range
+     * @param color the light's color.
+     * @param innerAngle the inner angle of the spotlight.
+     * @param outerAngle the outer angle of the spotlight.
+     * @param global if true, the light affects the entire tree from the root node,
+     * otherwise it only affects the children of the node in which it is attached.
+     * 
+     * @see SpotLight#setSpotInnerAngle(float) 
+     * @see SpotLight#setSpotOuterAngle(float) 
+     */
+    public SpotLight(Vector3f position, Vector3f direction, float range, ColorRGBA color, float innerAngle, float outerAngle, boolean global) {
+        this(position, direction, range, color, innerAngle, outerAngle);
+        this.global = global;
+    }  
+
+
     private void computeAngleParameters() {
         float innerCos = FastMath.cos(spotInnerAngle);
         outerAngleCos = FastMath.cos(spotOuterAngle);
diff --git a/jme3-core/src/main/java/com/jme3/scene/Node.java b/jme3-core/src/main/java/com/jme3/scene/Node.java
index 0424cea053..97ce830392 100644
--- a/jme3-core/src/main/java/com/jme3/scene/Node.java
+++ b/jme3-core/src/main/java/com/jme3/scene/Node.java
@@ -37,6 +37,8 @@
 import com.jme3.collision.CollisionResults;
 import com.jme3.export.JmeExporter;
 import com.jme3.export.JmeImporter;
+import com.jme3.light.Light;
+import com.jme3.light.LightList;
 import com.jme3.material.Material;
 import com.jme3.util.SafeArrayList;
 import com.jme3.util.clone.Cloner;
@@ -249,6 +251,23 @@ public void updateGeometricState() {
         if ((refreshFlags & RF_LIGHTLIST) != 0) {
             updateWorldLightList();
         }
+
+        boolean updateGlobalLights = (refreshFlags & RF_GLOBAL_LIGHTS) != 0;
+        if (updateGlobalLights){
+            refreshFlags &= ~RF_GLOBAL_LIGHTS;
+            // if root node, we collect the global lights
+            if (getParent() == null){ 
+                depthFirstTraversal(sx->{
+                    LightList childLights = sx.getLocalLightList();
+                    for (Light l : childLights) {
+                        if (l.isGlobal()) {
+                            worldLights.add(l);
+                        }
+                    }
+                });
+            }
+        }
+
         if ((refreshFlags & RF_TRANSFORM) != 0) {
             // combine with parent transforms- same for all spatial
             // subclasses.
diff --git a/jme3-core/src/main/java/com/jme3/scene/Spatial.java b/jme3-core/src/main/java/com/jme3/scene/Spatial.java
index 2fe1775d3e..9faf963355 100644
--- a/jme3-core/src/main/java/com/jme3/scene/Spatial.java
+++ b/jme3-core/src/main/java/com/jme3/scene/Spatial.java
@@ -124,7 +124,8 @@ public enum BatchHint {
             RF_BOUND = 0x02,
             RF_LIGHTLIST = 0x04, // changes in light lists
             RF_CHILD_LIGHTLIST = 0x08, // some child need geometry update
-            RF_MATPARAM_OVERRIDE = 0x10;
+            RF_MATPARAM_OVERRIDE = 0x10,
+            RF_GLOBAL_LIGHTS = 0x20; // world affecting lights changed
 
     protected CullHint cullHint = CullHint.Inherit;
     protected BatchHint batchHint = BatchHint.Inherit;
@@ -282,11 +283,22 @@ protected void setTransformRefresh() {
         setBoundRefresh();
     }
 
+    protected boolean hasGlobalLights(){
+        for(int i = 0;i<localLights.size();i++){
+            Light l = localLights.get(i);
+            if (l.isGlobal()) {
+                return true;
+            }
+        }
+        return false;
+    }
+ 
     protected void setLightListRefresh() {
         refreshFlags |= RF_LIGHTLIST;
         // Make sure next updateGeometricState() visits this branch
         // to update lights.
         Spatial p = parent;
+        boolean hasGlobalLights = hasGlobalLights();
         while (p != null) {
             if ((p.refreshFlags & RF_CHILD_LIGHTLIST) != 0) {
                 // The parent already has this flag,
@@ -294,6 +306,9 @@ protected void setLightListRefresh() {
                 return;
             }
             p.refreshFlags |= RF_CHILD_LIGHTLIST;
+            if (hasGlobalLights) {
+                p.refreshFlags |= RF_GLOBAL_LIGHTS;
+            }
             p = p.parent;
         }
     }
@@ -583,11 +598,11 @@ protected void updateWorldBound() {
 
     protected void updateWorldLightList() {
         if (parent == null) {
-            worldLights.update(localLights, null);
+            worldLights.update(localLights, null, l->!l.isGlobal());
             refreshFlags &= ~RF_LIGHTLIST;
         } else {
             assert (parent.refreshFlags & RF_LIGHTLIST) == 0 : "Illegal light list update. Problem spatial name: " + getName();
-            worldLights.update(localLights, parent.worldLights);
+            worldLights.update(localLights, parent.worldLights, l->!l.isGlobal());
             refreshFlags &= ~RF_LIGHTLIST;
         }
     }
diff --git a/jme3-plugins/src/gltf/java/com/jme3/scene/plugins/gltf/LightsPunctualExtensionLoader.java b/jme3-plugins/src/gltf/java/com/jme3/scene/plugins/gltf/LightsPunctualExtensionLoader.java
index 5b55c49b2e..9a9ecb7287 100644
--- a/jme3-plugins/src/gltf/java/com/jme3/scene/plugins/gltf/LightsPunctualExtensionLoader.java
+++ b/jme3-plugins/src/gltf/java/com/jme3/scene/plugins/gltf/LightsPunctualExtensionLoader.java
@@ -143,7 +143,7 @@ private SpotLight buildSpotLight(JsonObject obj) {
             outerConeAngle = FastMath.HALF_PI - 0.000001f;
         }
 
-        SpotLight spotLight = new SpotLight();
+        SpotLight spotLight = new SpotLight(true);
         spotLight.setName(name);
         spotLight.setColor(color);
         spotLight.setSpotRange(range);
@@ -167,7 +167,7 @@ private DirectionalLight buildDirectionalLight(JsonObject obj) {
         ColorRGBA color = obj.has("color") ? GltfUtils.getAsColor(obj, "color") : new ColorRGBA(ColorRGBA.White);
         color = lumensToColor(color, intensity);
 
-        DirectionalLight directionalLight = new DirectionalLight();
+        DirectionalLight directionalLight = new DirectionalLight(true);
         directionalLight.setName(name);
         directionalLight.setColor(color);
         directionalLight.setDirection(Vector3f.UNIT_Z.negate());
@@ -189,7 +189,7 @@ private PointLight buildPointLight(JsonObject obj) {
         color = lumensToColor(color, intensity);
         float range = obj.has("range") ? obj.get("range").getAsFloat() : Float.POSITIVE_INFINITY;
 
-        PointLight pointLight = new PointLight();
+        PointLight pointLight = new PointLight(true);
         pointLight.setName(name);
         pointLight.setColor(color);
         pointLight.setRadius(range);

From 08565997238cd230b65845fee36ef70fd7c9beda Mon Sep 17 00:00:00 2001
From: Riccardo Balbo <os@rblb.it>
Date: Sun, 10 Aug 2025 12:34:27 +0200
Subject: [PATCH 2/4] set refresh flag before light is removed

---
 jme3-core/src/main/java/com/jme3/scene/Spatial.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/jme3-core/src/main/java/com/jme3/scene/Spatial.java b/jme3-core/src/main/java/com/jme3/scene/Spatial.java
index 9faf963355..450a2065b3 100644
--- a/jme3-core/src/main/java/com/jme3/scene/Spatial.java
+++ b/jme3-core/src/main/java/com/jme3/scene/Spatial.java
@@ -1215,8 +1215,8 @@ public void addLight(Light light) {
      * @see Spatial#addLight(com.jme3.light.Light)
      */
     public void removeLight(Light light) {
-        localLights.remove(light);
         setLightListRefresh();
+        localLights.remove(light);
     }
 
     /**

From 3de0cd00c05a63fc324efbc8b7157271f8e953b4 Mon Sep 17 00:00:00 2001
From: Riccardo Balbo <os@rblb.it>
Date: Mon, 11 Aug 2025 19:28:38 +0200
Subject: [PATCH 3/4] optimize global lights refresh by following only paths
 with RF_GLOBAL_LIGHTS flag

---
 .../src/main/java/com/jme3/scene/Node.java    | 31 +++++++++++++------
 .../src/main/java/com/jme3/scene/Spatial.java |  6 ++++
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/jme3-core/src/main/java/com/jme3/scene/Node.java b/jme3-core/src/main/java/com/jme3/scene/Node.java
index 97ce830392..1e5c60fac2 100644
--- a/jme3-core/src/main/java/com/jme3/scene/Node.java
+++ b/jme3-core/src/main/java/com/jme3/scene/Node.java
@@ -242,6 +242,26 @@ public void updateLogicalState(float tpf) {
         }
     }
 
+    private void findGlobalLights(Spatial sp, LightList list) {
+        LightList lights = sp.getLocalLightList();
+        for (Light l : lights) {
+            if (l.isGlobal()) {
+                list.add(l);
+            }
+        }
+
+        if(sp instanceof Node){
+            Node n = (Node) sp;
+            List<Spatial> children = n.getChildren();
+            for (int i = 0; i < children.size(); i++) {
+                Spatial child = children.get(i);
+                if ((child.refreshFlags & RF_GLOBAL_LIGHTS)!= 0) {
+                    findGlobalLights(child, list);       
+                }
+            }
+        }
+    }
+
     @Override
     public void updateGeometricState() {
         if (refreshFlags == 0) {
@@ -254,18 +274,11 @@ public void updateGeometricState() {
 
         boolean updateGlobalLights = (refreshFlags & RF_GLOBAL_LIGHTS) != 0;
         if (updateGlobalLights){
-            refreshFlags &= ~RF_GLOBAL_LIGHTS;
             // if root node, we collect the global lights
             if (getParent() == null){ 
-                depthFirstTraversal(sx->{
-                    LightList childLights = sx.getLocalLightList();
-                    for (Light l : childLights) {
-                        if (l.isGlobal()) {
-                            worldLights.add(l);
-                        }
-                    }
-                });
+                findGlobalLights(this, worldLights);
             }
+            refreshFlags &= ~RF_GLOBAL_LIGHTS;
         }
 
         if ((refreshFlags & RF_TRANSFORM) != 0) {
diff --git a/jme3-core/src/main/java/com/jme3/scene/Spatial.java b/jme3-core/src/main/java/com/jme3/scene/Spatial.java
index 450a2065b3..0715479b56 100644
--- a/jme3-core/src/main/java/com/jme3/scene/Spatial.java
+++ b/jme3-core/src/main/java/com/jme3/scene/Spatial.java
@@ -299,6 +299,9 @@ protected void setLightListRefresh() {
         // to update lights.
         Spatial p = parent;
         boolean hasGlobalLights = hasGlobalLights();
+        if (hasGlobalLights){
+            refreshFlags |= RF_GLOBAL_LIGHTS;
+        }
         while (p != null) {
             if ((p.refreshFlags & RF_CHILD_LIGHTLIST) != 0) {
                 // The parent already has this flag,
@@ -967,6 +970,9 @@ public void updateGeometricState() {
         if ((refreshFlags & RF_MATPARAM_OVERRIDE) != 0) {
             updateMatParamOverrides();
         }
+        if ((refreshFlags & RF_GLOBAL_LIGHTS) != 0) {
+            refreshFlags &= ~RF_GLOBAL_LIGHTS;
+        }
         assert refreshFlags == 0 : "Illegal refresh flags state: " + refreshFlags + " for spatial " + getName();
     }
 

From 13edd167198e2424ca51019491e5e3aee3efff92 Mon Sep 17 00:00:00 2001
From: Riccardo Balbo <os@rblb.it>
Date: Sun, 24 Aug 2025 13:41:03 +0200
Subject: [PATCH 4/4] fix global lights refresh flag propagation

---
 jme3-core/src/main/java/com/jme3/scene/Node.java    | 9 ++++++++-
 jme3-core/src/main/java/com/jme3/scene/Spatial.java | 6 +++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/jme3-core/src/main/java/com/jme3/scene/Node.java b/jme3-core/src/main/java/com/jme3/scene/Node.java
index 1e5c60fac2..3aa37476ca 100644
--- a/jme3-core/src/main/java/com/jme3/scene/Node.java
+++ b/jme3-core/src/main/java/com/jme3/scene/Node.java
@@ -256,7 +256,7 @@ private void findGlobalLights(Spatial sp, LightList list) {
             for (int i = 0; i < children.size(); i++) {
                 Spatial child = children.get(i);
                 if ((child.refreshFlags & RF_GLOBAL_LIGHTS)!= 0) {
-                    findGlobalLights(child, list);       
+                    findGlobalLights(child, list);
                 }
             }
         }
@@ -298,6 +298,13 @@ public void updateGeometricState() {
             // NOTE 9/19/09
             // Although it does save a round trip,
             for (Spatial child : children.getArray()) {
+                if (updateGlobalLights){
+                    // we might have new global lights coming from a different
+                    // branch of the scene graph, so we need to propagate the
+                    // refresh flags down to all the children of every branch
+                    child.refreshFlags |= RF_LIGHTLIST;
+                    child.refreshFlags |= RF_GLOBAL_LIGHTS;
+                }
                 child.updateGeometricState();
             }
         }
diff --git a/jme3-core/src/main/java/com/jme3/scene/Spatial.java b/jme3-core/src/main/java/com/jme3/scene/Spatial.java
index 0715479b56..384bbf643a 100644
--- a/jme3-core/src/main/java/com/jme3/scene/Spatial.java
+++ b/jme3-core/src/main/java/com/jme3/scene/Spatial.java
@@ -303,7 +303,10 @@ protected void setLightListRefresh() {
             refreshFlags |= RF_GLOBAL_LIGHTS;
         }
         while (p != null) {
-            if ((p.refreshFlags & RF_CHILD_LIGHTLIST) != 0) {
+            if (
+                (p.refreshFlags & RF_CHILD_LIGHTLIST) != 0
+                && (!hasGlobalLights || (p.refreshFlags & RF_GLOBAL_LIGHTS) != 0)
+            ) {
                 // The parent already has this flag,
                 // so must all ancestors.
                 return;
@@ -311,6 +314,7 @@ protected void setLightListRefresh() {
             p.refreshFlags |= RF_CHILD_LIGHTLIST;
             if (hasGlobalLights) {
                 p.refreshFlags |= RF_GLOBAL_LIGHTS;
+                p.refreshFlags |= RF_LIGHTLIST;
             }
             p = p.parent;
         }