diff --git a/static/script.js b/static/script.js
index 7a3062ac..218dcef8 100644
--- a/static/script.js
+++ b/static/script.js
@@ -3607,18 +3607,13 @@ const DUNGEON_DISPLAY_COLORS = {
   stairs:      { r: 180, g: 160, b: 80  },  // yellowish stairs
 };
 
-// Process a tile image: flip horizontally (UB tiles authored for mirrored-X),
-// make white transparent, remap UB colors
+// Process a tile image: make white transparent, remap UB colors
 function processTileImage(img) {
   const c = document.createElement('canvas');
   c.width = 10;
   c.height = 10;
   const ctx = c.getContext('2d');
-  // Flip horizontally: tiles were designed for UB's mirrored-X coordinate system
-  ctx.translate(10, 0);
-  ctx.scale(-1, 1);
   ctx.drawImage(img, 0, 0, 10, 10);
-  ctx.setTransform(1, 0, 0, 1, 0, 0);
   const imageData = ctx.getImageData(0, 0, 10, 10);
   const d = imageData.data;
 
@@ -3862,14 +3857,11 @@ function updateRadarWindow(msg) {
     const cellSize = 10 * scale; // each cell is 10 game units
     const hasTiles = dungeonTileCanvases && Object.keys(dungeonTileCanvases).length > 0;
 
-    // Normalize rotation value to radians (from UB's DungeonCell.cs)
-    // Negated because tile images are horizontally flipped to compensate
-    // for UB's mirrored-X authoring space
+    // Normalize rotation value to radians (exact copy of UB's DungeonCell.cs)
     function cellRotation(rot) {
-      if (Math.abs(rot - 1) < 0.01) return Math.PI;   // 180° = -180°, same
-      if (Math.abs(rot + 1) < 0.01) return Math.PI;
-      if (rot < -0.70 && rot > -0.8) return -Math.PI / 2;  // negated
-      if (rot > 0.70 && rot < 0.8) return Math.PI / 2;     // negated
+      if (rot === 1) return Math.PI;
+      if (rot < -0.70 && rot > -0.8) return Math.PI / 2;
+      if (rot > 0.70 && rot < 0.8) return -Math.PI / 2;
       return 0;
     }
 
@@ -3885,9 +3877,8 @@ function updateRadarWindow(msg) {
       ctx.globalAlpha = isCurrentFloor ? 0.85 : 0.12;
 
       (level.cells || []).forEach(cell => {
-        // Direct relative position (UB mirrors both cell and player, cancels out)
-        // Y negated for north-up (AC Y+ = north, canvas Y+ = down)
-        const dx = (cell.x - playerX) * scale;
+        // X mirrored (matches UB's layer rendering), Y negated for north-up
+        const dx = -(cell.x - playerX) * scale;
         const dy = -(cell.y - playerY) * scale;
         const tileCanvas = hasTiles ? dungeonTileCanvases[String(cell.env_id)] : null;
 
@@ -3985,8 +3976,8 @@ function updateRadarWindow(msg) {
     // Use raw physics coords in dungeons (X mirrored), EW/NS on surface
     let dX, dY;
     if (isDungeon && obj.raw_x !== undefined) {
-      dX = (obj.raw_x - playerX);
-      dY = -(obj.raw_y - playerY);  // Y flipped for north-up
+      dX = -(obj.raw_x - playerX);  // X mirrored to match tile space
+      dY = -(obj.raw_y - playerY);  // Y negated for north-up
     } else {
       dX = obj.ew - playerEW;
       dY = obj.ns - playerNS;
@@ -4048,8 +4039,8 @@ function updateRadarWindow(msg) {
   const withDist = objects.map(obj => {
     let distMeters, dX, dY;
     if (isDungeon && obj.raw_x !== undefined) {
-      dX = (obj.raw_x - playerX);
-      dY = -(obj.raw_y - playerY);
+      dX = -(obj.raw_x - playerX);  // X mirrored
+      dY = -(obj.raw_y - playerY);  // Y negated
       distMeters = Math.sqrt(dX * dX + dY * dY); // raw coords are ~meters
     } else {
       dX = obj.ew - playerEW;