diff --git a/ui/src/ShadingSandbox.vue b/ui/src/ShadingSandbox.vue
index db705b9..f591af1 100644
--- a/ui/src/ShadingSandbox.vue
+++ b/ui/src/ShadingSandbox.vue
@@ -192,6 +192,9 @@ let animationId = null;
 // Geometry cache for height exaggeration
 let geometryCache = null;
 
+// Resize observer
+let resizeObserver = null;
+
 // Initialize Three.js
 const initThreeJS = () => {
   if (!canvasRef.value) return;
@@ -213,9 +216,8 @@ const initThreeJS = () => {
   });
   
   const width = canvasRef.value.clientWidth || 800;
-  const height = canvasRef.value.clientHeight || 800;
-  const size = Math.min(width, height);
-  renderer.setSize(size,size);
+  const height = canvasRef.value.clientHeight || 600;
+  renderer.setSize(width, height);
   renderer.setPixelRatio(window.devicePixelRatio);
 
   // Lights
@@ -237,6 +239,25 @@ const initThreeJS = () => {
   animate();
 };
 
+// Handle canvas resize
+const handleResize = () => {
+  if (!canvasRef.value || !renderer || !camera) return;
+  
+  const width = canvasRef.value.clientWidth || 800;
+  const height = canvasRef.value.clientHeight || 600;
+  
+  renderer.setSize(width, height);
+  renderer.setPixelRatio(window.devicePixelRatio);
+  
+  // Always maintain square frustum regardless of canvas aspect ratio
+  const viewSize = 6;
+  camera.left = -viewSize;
+  camera.right = viewSize;
+  camera.top = viewSize;
+  camera.bottom = -viewSize;
+  camera.updateProjectionMatrix();
+};
+
 // Load tile data
 const loadTileData = (tileData) => {
   if (!scene) {
@@ -317,12 +338,10 @@ const loadTileData = (tileData) => {
     mesh = new THREE.Mesh(geometry, material);
     scene.add(mesh);
 
-    // Configure camera frustum for orthographic view
-    // We want to see the 10-unit box with some padding
-    const aspect = canvasRef.value.clientWidth / canvasRef.value.clientHeight;
+    // Configure camera frustum for orthographic view - ALWAYS SQUARE
     const viewSize = 6; // 10-unit terrain + padding
-    camera.left = -viewSize * aspect;
-    camera.right = viewSize * aspect;
+    camera.left = -viewSize;
+    camera.right = viewSize;
     camera.top = viewSize;
     camera.bottom = -viewSize;
     
@@ -508,11 +527,10 @@ const renderTileWithSettings = async (tileData, renderSettings, resolution = 102
     renderer.setSize(resolution, resolution);
     renderer.setPixelRatio(1);
 
-    // Update camera for square aspect
-    const aspect = 1;
+    // Update camera for square aspect (always square)
     const viewSize = 6;
-    camera.left = -viewSize * aspect;
-    camera.right = viewSize * aspect;
+    camera.left = -viewSize;
+    camera.right = viewSize;
     camera.top = viewSize;
     camera.bottom = -viewSize;
     camera.updateProjectionMatrix();
@@ -527,10 +545,9 @@ const renderTileWithSettings = async (tileData, renderSettings, resolution = 102
     renderer.setSize(originalWidth / originalPixelRatio, originalHeight / originalPixelRatio);
     renderer.setPixelRatio(originalPixelRatio);
 
-    // Restore camera aspect
-    const canvasAspect = originalWidth / originalHeight;
-    camera.left = -viewSize * canvasAspect;
-    camera.right = viewSize * canvasAspect;
+    // Restore camera (always square frustum)
+    camera.left = -viewSize;
+    camera.right = viewSize;
     camera.top = viewSize;
     camera.bottom = -viewSize;
     camera.updateProjectionMatrix();
@@ -571,6 +588,10 @@ const cleanup = () => {
   if (animationId) {
     cancelAnimationFrame(animationId);
   }
+  if (resizeObserver) {
+    resizeObserver.disconnect();
+    resizeObserver = null;
+  }
   if (renderer) {
     renderer.dispose();
   }
@@ -585,6 +606,14 @@ onMounted(() => {
   if (props.visible) {
     nextTick(() => {
       initThreeJS();
+      
+      // Set up resize observer
+      if (canvasRef.value) {
+        resizeObserver = new ResizeObserver(() => {
+          handleResize();
+        });
+        resizeObserver.observe(canvasRef.value);
+      }
     });
   }
 });
@@ -594,6 +623,14 @@ watch(() => props.visible, (newVal) => {
   if (newVal && !renderer) {
     nextTick(() => {
       initThreeJS();
+      
+      // Set up resize observer
+      if (canvasRef.value && !resizeObserver) {
+        resizeObserver = new ResizeObserver(() => {
+          handleResize();
+        });
+        resizeObserver.observe(canvasRef.value);
+      }
     });
   }
 });