Refresh instanced bounds after source geometry updates

jme3-core/src/main/java/com/jme3/scene/instancing/InstancedNode.java

@@ -199,6 +199,17 @@ public InstancedNode(String name) {
         addControl(control);
     }
 
+    @Override
+    protected void updateWorldBound() {
+        // Source geometries can change their bounds without changing the
+        // transform of the InstancedGeometry that renders them. Refresh the
+        // aggregate bounds after all source children have been updated.
+        for (InstancedGeometry ig : instancesMap.values()) {
+            ig.updateWorldBound();
+        }
+        super.updateWorldBound();
+    }
+
     private void renderFromControl(Camera cam) {
         for (InstancedGeometry ig : instancesMap.values()) {
             ig.updateInstances(cam);

jme3-core/src/test/java/com/jme3/scene/instancing/InstancedBoundsTest.java

@@ -0,0 +1,190 @@
+/*
+ * Copyright (c) 2026 jMonkeyEngine
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.jme3.scene.instancing;
+
+import com.jme3.asset.DesktopAssetManager;
+import com.jme3.bounding.BoundingBox;
+import com.jme3.light.DefaultLightFilter;
+import com.jme3.light.LightList;
+import com.jme3.light.PointLight;
+import com.jme3.material.Material;
+import com.jme3.material.MaterialDef;
+import com.jme3.math.Vector3f;
+import com.jme3.renderer.Camera;
+import com.jme3.scene.Geometry;
+import com.jme3.scene.Node;
+import com.jme3.scene.Spatial;
+import com.jme3.scene.shape.Box;
+import com.jme3.shader.VarType;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+/**
+ * Verifies that instance bounds follow changes to the source geometries.
+ */
+public class InstancedBoundsTest {
+
+    @Test
+    public void movingInstanceUpdatesBounds() {
+        checkMovedInstanceBounds(false);
+    }
+
+    @Test
+    public void movingInstanceAfterItsBatchUpdatesBounds() {
+        checkMovedInstanceBounds(true);
+    }
+
+    private void checkMovedInstanceBounds(boolean batchFirst) {
+        Fixture fixture = new Fixture(false);
+        if (batchFirst) {
+            fixture.node.swapChildren(0, 1);
+        }
+        fixture.geometry.move(20, 0, 0);
+        fixture.update();
+
+        assertEquals(new Vector3f(20, 0, 10), fixture.geometry.getWorldBound().getCenter());
+        fixture.assertBounds();
+    }
+
+    @Test
+    public void movingNestedParentUpdatesBounds() {
+        Fixture fixture = new Fixture(true);
+        fixture.geometry.getParent().move(20, 0, 0);
+        fixture.update();
+        fixture.assertBounds();
+    }
+
+    @Test
+    public void parentTraversalUpdatesInstancedChildBounds() {
+        Fixture fixture = new Fixture(false);
+        Node root = new Node("root");
+        root.attachChild(fixture.node);
+        root.updateGeometricState();
+
+        fixture.geometry.move(20, 0, 0);
+        root.updateLogicalState(0);
+        root.updateGeometricState();
+
+        fixture.assertBounds();
+        assertEquals(fixture.geometry.getWorldBound(), root.getWorldBound());
+    }
+
+    @Test
+    public void changingModelBoundUpdatesBounds() {
+        Fixture fixture = new Fixture(false);
+        fixture.geometry.setModelBound(new BoundingBox(Vector3f.ZERO, 4, 5, 6));
+        fixture.update();
+        fixture.assertBounds();
+    }
+
+    @Test
+    public void queryingNodeBoundUpdatesInstanceBounds() {
+        Fixture fixture = new Fixture(false);
+        fixture.geometry.move(20, 0, 0);
+        // A direct bounds query also runs the normal lazy bound update path.
+        assertEquals(fixture.geometry.getWorldBound(), fixture.node.getWorldBound());
+        fixture.assertBounds();
+    }
+
+    @Test
+    public void movingInstanceKeepsNearbyPointLight() {
+        Fixture fixture = new Fixture(false);
+        PointLight light = new PointLight(new Vector3f(20, 0, 10));
+        light.setRadius(3);
+        fixture.node.addLight(light);
+        fixture.update();
+
+        Camera camera = new Camera(100, 100);
+        camera.setFrustum(1, 100, -50, 50, 50, -50);
+        camera.lookAtDirection(Vector3f.UNIT_Z, Vector3f.UNIT_Y);
+        DefaultLightFilter filter = new DefaultLightFilter();
+        LightList filtered = new LightList(fixture.batch);
+        filter.setCamera(camera);
+        filter.filterLights(fixture.batch, filtered);
+        assertEquals(0, filtered.size(), "The light initially does not reach the instance");
+
+        fixture.geometry.move(20, 0, 0);
+        fixture.update();
+        fixture.batch.updateInstances(camera);
+        assertEquals(1, fixture.batch.getNumVisibleInstances());
+        filter.setCamera(camera);
+        filtered.clear();
+        filter.filterLights(fixture.batch, filtered);
+        assertEquals(1, filtered.size(), "The light now reaches the moved instance");
+        assertSame(light, filtered.get(0));
+    }
+
+    private static class Fixture {
+        final InstancedNode node = new InstancedNode("instances");
+        final Geometry geometry = new Geometry("instance", new Box(1, 1, 1));
+        final InstancedGeometry batch;
+
+        Fixture(boolean nested) {
+            MaterialDef def = new MaterialDef(new DesktopAssetManager(), "test");
+            def.addMaterialParam(VarType.Boolean, "UseInstancing", false);
+            Material material = new Material(def);
+            material.setBoolean("UseInstancing", true);
+            geometry.setMaterial(material);
+            geometry.setLocalTranslation(0, 0, 10);
+            Node parent = node;
+            if (nested) {
+                parent = new Node("nested");
+                node.attachChild(parent);
+            }
+            parent.attachChild(geometry);
+            node.instance();
+            InstancedGeometry found = null;
+            for (Spatial child : node.getChildren()) {
+                if (child instanceof InstancedGeometry) {
+                    found = (InstancedGeometry) child;
+                }
+            }
+            assertNotNull(found);
+            batch = found;
+            update();
+            assertBounds();
+        }
+
+        void update() {
+            node.updateLogicalState(0);
+            node.updateGeometricState();
+        }
+
+        void assertBounds() {
+            assertEquals(geometry.getWorldBound(), batch.getWorldBound());
+            assertEquals(geometry.getWorldBound(), node.getWorldBound());
+        }
+    }
+}