diff --git a/tools/zernike_html_generator.py b/tools/zernike_html_generator.py
index fe606c47..b9e3e1b9 100644
--- a/tools/zernike_html_generator.py
+++ b/tools/zernike_html_generator.py
@@ -655,22 +655,31 @@ def main_opd(op2_path: Path):
 
     print(f"\nAvailable subcases: {list(extractor.displacements.keys())}")
 
-    # Map subcases (try common patterns)
+    # Map subcases - find required angles by name (robust to extra subcases)
     displacements = extractor.displacements
+    required_angles = ['90', '20', '40', '60']
     subcase_map = {}
 
-    if '1' in displacements and '2' in displacements:
-        subcase_map = {'90': '1', '20': '2', '40': '3', '60': '4'}
-    elif '90' in displacements and '20' in displacements:
-        subcase_map = {'90': '90', '20': '20', '40': '40', '60': '60'}
-    else:
-        available = sorted(displacements.keys(), key=lambda x: int(x) if x.isdigit() else 0)
-        if len(available) >= 4:
-            subcase_map = {'90': available[0], '20': available[1], '40': available[2], '60': available[3]}
-            print(f"[WARN] Using mapped subcases: {subcase_map}")
-        else:
-            print(f"[ERROR] Need 4 subcases, found: {available}")
-            return
+    # First, try direct angle matching (e.g., "20", "40", "60", "90")
+    for angle in required_angles:
+        if angle in displacements:
+            subcase_map[angle] = angle
+
+    # If we didn't find all angles, try numeric IDs (e.g., "1"=90, "2"=20, "3"=40, "4"=60)
+    if len(subcase_map) < 4:
+        if all(str(i) in displacements for i in range(1, 5)):
+            subcase_map = {'90': '1', '20': '2', '40': '3', '60': '4'}
+            print(f"[INFO] Using numeric subcases: 1=90°, 2=20°, 3=40°, 4=60°")
+
+    # Check if we found all required angles
+    if len(subcase_map) < 4:
+        missing = [a for a in required_angles if a not in subcase_map]
+        print(f"[ERROR] Missing required subcases: {missing}")
+        print(f"[ERROR] Available subcases: {list(displacements.keys())}")
+        print(f"[ERROR] Required subcases must be named: {required_angles} (or numeric 1,2,3,4)")
+        return
+
+    print(f"[INFO] Using subcase mapping: {subcase_map}")
 
     output_dir = op2_path.parent
     base = op2_path.stem
@@ -898,26 +907,30 @@ def main(op2_path: Path):
     displacements = read_displacements(op2_path)
     print(f"Found subcases: {list(displacements.keys())}")
 
-    # Map subcases (try common patterns)
-    # Pattern 1: Direct labels (1, 2, 3, 4)
-    # Pattern 2: Angle labels (90, 20, 40, 60)
+    # Map subcases - find required angles by name (robust to extra subcases)
+    required_angles = ['90', '20', '40', '60']
     subcase_map = {}
 
-    if '1' in displacements and '2' in displacements:
-        # Standard NX pattern: 1=90deg, 2=20deg, 3=40deg, 4=60deg
-        subcase_map = {'90': '1', '20': '2', '40': '3', '60': '4'}
-    elif '90' in displacements and '20' in displacements:
-        # Direct angle labels
-        subcase_map = {'90': '90', '20': '20', '40': '40', '60': '60'}
-    else:
-        # Try to use whatever is available
-        available = sorted(displacements.keys(), key=lambda x: int(x) if x.isdigit() else 0)
-        if len(available) >= 4:
-            subcase_map = {'90': available[0], '20': available[1], '40': available[2], '60': available[3]}
-            print(f"[WARN] Using mapped subcases: {subcase_map}")
-        else:
-            print(f"[ERROR] Need 4 subcases, found: {available}")
-            return
+    # First, try direct angle matching (e.g., "20", "40", "60", "90")
+    for angle in required_angles:
+        if angle in displacements:
+            subcase_map[angle] = angle
+
+    # If we didn't find all angles, try numeric IDs (e.g., "1"=90, "2"=20, "3"=40, "4"=60)
+    if len(subcase_map) < 4:
+        if all(str(i) in displacements for i in range(1, 5)):
+            subcase_map = {'90': '1', '20': '2', '40': '3', '60': '4'}
+            print(f"[INFO] Using numeric subcases: 1=90°, 2=20°, 3=40°, 4=60°")
+
+    # Check if we found all required angles
+    if len(subcase_map) < 4:
+        missing = [a for a in required_angles if a not in subcase_map]
+        print(f"[ERROR] Missing required subcases: {missing}")
+        print(f"[ERROR] Available subcases: {list(displacements.keys())}")
+        print(f"[ERROR] Required subcases must be named: {required_angles} (or numeric 1,2,3,4)")
+        return
+
+    print(f"[INFO] Using subcase mapping: {subcase_map}")
 
     # Check all required subcases exist
     for angle, label in subcase_map.items():
diff --git a/tools/zernike_html_generator_annular.py b/tools/zernike_html_generator_annular.py
index c7c8f5aa..afd11ee0 100644
--- a/tools/zernike_html_generator_annular.py
+++ b/tools/zernike_html_generator_annular.py
@@ -747,25 +747,30 @@ def main_annular(op2_path: Path, inner_radius_mm: float):
     displacements = read_displacements(op2_path)
     print(f"Found subcases: {list(displacements.keys())}")
 
-    # Map subcases
+    # Map subcases - find required angles by name (robust to extra subcases)
+    required_angles = ['90', '20', '40', '60']
     subcase_map = {}
-    if '1' in displacements and '2' in displacements:
-        subcase_map = {'90': '1', '20': '2', '40': '3', '60': '4'}
-    elif '90' in displacements and '20' in displacements:
-        subcase_map = {'90': '90', '20': '20', '40': '40', '60': '60'}
-    else:
-        available = sorted(displacements.keys(), key=lambda x: int(x) if x.isdigit() else 0)
-        if len(available) >= 4:
-            subcase_map = {'90': available[0], '20': available[1], '40': available[2], '60': available[3]}
-            print(f"[WARN] Using mapped subcases: {subcase_map}")
-        else:
-            print(f"[ERROR] Need 4 subcases, found: {available}")
-            return
 
-    for angle, label in subcase_map.items():
-        if label not in displacements:
-            print(f"[ERROR] Subcase '{label}' (angle {angle}) not found")
-            return
+    # First, try direct angle matching (e.g., "20", "40", "60", "90")
+    for angle in required_angles:
+        if angle in displacements:
+            subcase_map[angle] = angle
+
+    # If we didn't find all angles, try numeric IDs (e.g., "1"=90, "2"=20, "3"=40, "4"=60)
+    if len(subcase_map) < 4:
+        if all(str(i) in displacements for i in range(1, 5)):
+            subcase_map = {'90': '1', '20': '2', '40': '3', '60': '4'}
+            print(f"[INFO] Using numeric subcases: 1=90°, 2=20°, 3=40°, 4=60°")
+
+    # Check if we found all required angles
+    if len(subcase_map) < 4:
+        missing = [a for a in required_angles if a not in subcase_map]
+        print(f"[ERROR] Missing required subcases: {missing}")
+        print(f"[ERROR] Available subcases: {list(displacements.keys())}")
+        print(f"[ERROR] Required subcases must be named: {required_angles} (or numeric 1,2,3,4)")
+        return
+
+    print(f"[INFO] Using subcase mapping: {subcase_map}")
 
     output_dir = op2_path.parent
     base = op2_path.stem