Refactor extrusion process to use Solidify Modifier for improved thickness control

pcb_to_stl.py

@@ -56,24 +56,29 @@ if bpy.context.selected_objects:
             print(f"Resizing: {current_width:.2f}mm -> {target_width_mm:.2f}mm (Factor: {scale_factor:.4f})")
             
             # Apply Scale to X and Y (Maintain Aspect Ratio)
-            # We do NOT scale Z because Z is 0 (flat mesh)
             obj.scale[0] = scale_factor
             obj.scale[1] = scale_factor
             
-            # Freeze the scale transformation so dimensions are real
+            # Freeze the scale transformation so dimensions are real before adding modifiers
             bpy.ops.object.transform_apply(location=False, rotation=False, scale=True)
         else:
             print("Warning: Object has 0 width, skipping resize.")
 
-    # 3. Extrude (Z-Height)
-    # Now that X/Y are sized correctly, we extrude Z
-    bpy.ops.object.mode_set(mode='EDIT')
-    bpy.ops.mesh.select_all(action='SELECT')
+    # 3. Add Solidify Modifier (Replaces manual extrusion)
+    print(f"Applying Solidify Modifier: Thickness {thickness_mm}mm")
     
-    # Extrude exactly the thickness value
-    bpy.ops.mesh.extrude_region_move(TRANSFORM_OT_translate={"value":(0, 0, thickness_mm)}) 
-
-    bpy.ops.object.mode_set(mode='OBJECT')
+    # Add the modifier
+    mod = obj.modifiers.new(name='PCBSolidify', type='SOLIDIFY')
+    
+    # Set Modifier Properties
+    mod.thickness = thickness_mm
+    mod.use_even_offset = True  # "Even Thickness: yes"
+    mod.use_rim = True          # "Fill Rim: ON"
+    mod.offset = 0              # 0 centers the thickness, 1 extends vertically. 
+                                # Use 0 or 1 depending on where you want the origin.
+    
+    # Apply the modifier (Bake it into the mesh)
+    bpy.ops.object.modifier_apply(modifier=mod.name)
 
     # --- Step 4: Export STL ---
     print(f"Exporting to: {output_stl}")