projection removed

app.py

@@ -141,45 +141,20 @@ async def generate_model(request: GenerateRequest):
         # PyPRT expects flat list or specific structure depending on version
         # Using simple approach: create initial shape from vertices
         
-        # Auto-project if coordinates look like Lat/Lon
-        # Simple heuristic: x within [-180, 180], y within [-90, 90]
+        # Coordinate Processing for Local Tangent Plane
+        # The frontend now sends coordinates in proper local meters (ENU frame).
+        # We do NOT project or transform them. We explicitly trust the frontend input.
+        
+        # We also don't need to re-center, as the frontend sends relative coordinates from the centroid (0,0).
+        # But to be safe, we can ensure centering if the frontend doesn't perfectly center around 0,0.
+        # Actually, DrawTools sends vectors from center, so they are practically centered.
+        # We'll calculate bounds just for logging.
         bounds = shape.bounds
-        if -180 <= bounds[0] <= 180 and -90 <= bounds[1] <= 90:
-            logger.info("Detected geographic coordinates. Projecting to UTM...")
-            centroid = shape.centroid
-            lon = centroid.x
-            lat = centroid.y
-            
-            # Project to Web Mercator (EPSG:3857)
-            # User requested usage of projected web mercator
-            logger.info("Projecting to Web Mercator (EPSG:3857)...")
-            
-            proj_str = "epsg:3857"
-                
-            project = functools.partial(
-                pyproj.transform,
-                pyproj.Proj(init='epsg:4326'), # Source: WGS84
-                pyproj.Proj(init='epsg:3857')  # Target: Web Mercator
-            )
-            
-            shape = transform(project, shape)
-            logger.info(f"Projected geometry bounds: {shape.bounds}")
-            
-            # Re-center geometry to (0,0) for model generation
-            # This ensures the local origin of the GLB is the center of the building
-            projected_centroid = shape.centroid
-            shape = translate(shape, xoff=-projected_centroid.x, yoff=-projected_centroid.y)
-            
-            # We need to return the original Lat/Lon centroid for placement
-            # Actually we already have it: `lat` and `lon` from earlier
-            centroid_lat = lat
-            centroid_lon = lon
-        else:
-            # If already metric, assume centroid is 0,0 or we take existing?
-            # For simplicity, if not projected, we assume it's already local/centered or user handles it.
-            # But we can still calculate centroid to be safe if wanted.
-            centroid_lat = 0.0
-            centroid_lon = 0.0
+        logger.info(f"Received geometry bounds: {bounds}")
+        
+        # Centroid should be near 0,0
+        centroid = shape.centroid
+        logger.info(f"Geometry Centroid: {centroid.x}, {centroid.y}")
             
         coords = list(shape.exterior.coords)
         # Remove last point if duplicate (closed loop)
@@ -248,31 +223,9 @@ async def generate_model(request: GenerateRequest):
                 raise HTTPException(status_code=500, detail=f"GLB Conversion failed: {str(e)}")
 
             if os.path.exists(glb_path):
-                # Calculate meridian convergence (grid north vs true north)
-                # This angle is in degrees. Positive means Grid North is East of True North.
-                # To align Grid North (Model) to True North (Cesium), we usually subtract this angle.
-                convergence_angle = 0.0
-                try:
-                    # Create a pipeline to get factors
-                    # We need the projection object
-                    proj_target = pyproj.Proj(init='epsg:3857')
-                    
-                    # Calculate convergence
-                    factors = proj_target.get_factors(centroid_lon, centroid_lat)
-                    convergence_angle = factors.meridian_convergence
-                    logger.info(f"Calculated convergence angle: {convergence_angle} degrees")
-                    
-                except Exception as e:
-                    logger.warning(f"Could not calculate convergence angle: {e}")
-                
-                # We return the GLB file. 
-                # Note: The temp dir will be cleaned up by OS eventually or we should handle it better.
-                headers = {
-                    "X-Centroid-Lat": str(centroid_lat),
-                    "X-Centroid-Lon": str(centroid_lon),
-                    "X-Convergence-Angle": str(convergence_angle)
-                }
-                return FileResponse(glb_path, media_type="model/gltf-binary", filename="output.glb", headers=headers)
+                # No headers needed for placement logic anymore.
+                # The frontend reconstructs placement from its own state.
+                return FileResponse(glb_path, media_type="model/gltf-binary", filename="output.glb")
             else:
                  logger.error(f"GLB file not created at {glb_path}")
                  raise HTTPException(status_code=500, detail="GLB generation failed: Conversion produced no output")