diff --git a/app/components/Form.tsx b/app/components/Form.tsx
index ab47784..10d871a 100644
--- a/app/components/Form.tsx
+++ b/app/components/Form.tsx
@@ -166,13 +166,12 @@ export function Form() {
     if (!sceneView) return;
 
     sceneView.toggleLayerVisibility(name);
-    sceneView.dispatchChangeEvent();
   }
 
   function handleChangeTopography() {
     if (!sceneView) return;
 
-    sceneView.toggleTopography();
+    sceneView.toggleLayerVisibility("Topography");
   }
 
   function handleDrilling(e: ChangeEvent) {
diff --git a/app/three/SceneView.ts b/app/three/SceneView.ts
index 02de088..67457b1 100644
--- a/app/three/SceneView.ts
+++ b/app/three/SceneView.ts
@@ -129,7 +129,7 @@ export class SceneView extends EventTarget {
 
       if (capMeshGroup) {
         for (const m of capMeshGroup.children) {
-          if (m.name === layerName && m) {
+          if (m && m.name === layerName) {
             m.visible = !m.visible;
           }
         }
@@ -171,13 +171,6 @@ export class SceneView extends EventTarget {
     }
   }
 
-  toggleTopography() {
-    const topo = this._scene.getObjectByName("Topography");
-    if (topo) {
-      topo.visible = !topo.visible;
-    }
-  }
-
   private _onPointerClick(event: MouseEvent) {
     // Convert screen position to NDC (-1 to +1 range)
     const pointer = new Vector2();
@@ -434,10 +427,6 @@ export class SceneView extends EventTarget {
       this._resetClippingBox();
     }
   }
-
-  dispatchChangeEvent() {
-    this._orbitControls.dispatchEvent({ type: "change" });
-  }
 }
 
 async function init(container: HTMLElement, modelId = MODEL_ID) {