diff --git a/dataforge-vis-common/src/commonMain/kotlin/hep/dataforge/vis/common/AbstractVisualObject.kt b/dataforge-vis-common/src/commonMain/kotlin/hep/dataforge/vis/common/AbstractVisualObject.kt
index 7d75df0a..7701eb1c 100644
--- a/dataforge-vis-common/src/commonMain/kotlin/hep/dataforge/vis/common/AbstractVisualObject.kt
+++ b/dataforge-vis-common/src/commonMain/kotlin/hep/dataforge/vis/common/AbstractVisualObject.kt
@@ -48,8 +48,10 @@ abstract class AbstractVisualObject : VisualObject {
     private val listeners = HashSet<PropertyListener>()
 
     override fun propertyChanged(name: Name, before: MetaItem<*>?, after: MetaItem<*>?) {
-        for (l in listeners) {
-            l.action(name, before, after)
+        if (before != after) {
+            for (l in listeners) {
+                l.action(name, before, after)
+            }
         }
     }
 
diff --git a/dataforge-vis-spatial/src/jsMain/kotlin/hep/dataforge/vis/spatial/three/ThreeMaterials.kt b/dataforge-vis-spatial/src/jsMain/kotlin/hep/dataforge/vis/spatial/three/ThreeMaterials.kt
index edc760c7..a1e9495e 100644
--- a/dataforge-vis-spatial/src/jsMain/kotlin/hep/dataforge/vis/spatial/three/ThreeMaterials.kt
+++ b/dataforge-vis-spatial/src/jsMain/kotlin/hep/dataforge/vis/spatial/three/ThreeMaterials.kt
@@ -93,7 +93,7 @@ fun MetaItem<*>.color(): Color {
 
 fun Mesh.updateMaterial(obj: VisualObject) {
     val meta = obj.getProperty(Material3D.MATERIAL_KEY).node?:EmptyMeta
-    material = (material as? MeshBasicMaterial ?: MeshBasicMaterial()).apply {
+    material = MeshBasicMaterial().apply {
         color = meta[Material3D.COLOR_KEY]?.color() ?: ThreeMaterials.DEFAULT_COLOR
         opacity = meta[Material3D.OPACITY_KEY]?.double ?: 1.0
         transparent = opacity < 1.0
diff --git a/demo/gdml/build.gradle.kts b/demo/gdml/build.gradle.kts
index 8ba1dcfc..67570e1d 100644
--- a/demo/gdml/build.gradle.kts
+++ b/demo/gdml/build.gradle.kts
@@ -15,7 +15,7 @@ kotlin {
     js {
         browser {
             webpackTask {
-                sourceMaps = false
+                //sourceMaps = false
             }
         }
     }