Add model CRS with automatic spatial transformation

loopstructural/gui/modelling/geological_model_tab/geological_model_tab.py

@@ -150,6 +150,26 @@ def initialize_model(self):
                     "Please set the bounding box before initializing the model.",
                 )
                 return
+
+            # Validate model CRS
+            if not self.data_manager.is_model_crs_valid():
+                crs = self.data_manager.get_model_crs()
+                if crs is None or not crs.isValid():
+                    msg = "Model CRS is not set or invalid. Please select a valid projected CRS in the Model Definition tab."
+                else:
+                    # Safely get CRS description
+                    try:
+                        crs_desc = crs.description() or crs.authid() or "Unknown"
+                    except Exception:
+                        crs_desc = crs.authid() if hasattr(crs, 'authid') else "Unknown"
+                    msg = f"Model CRS must be projected (in meters), not geographic.\nSelected CRS: {crs_desc}\n\nPlease select a valid projected CRS in the Model Definition tab."
+
+                QMessageBox.critical(
+                    self,
+                    "Invalid Model CRS",
+                    msg,
+                )
+                return
 
         # create progress dialog (indeterminate)
         progress = QProgressDialog("Updating geological model...", "Cancel", 0, 0, self)

loopstructural/gui/modelling/model_definition/bounding_box.py

@@ -2,6 +2,7 @@
 
 import numpy as np
 from PyQt5.QtWidgets import QWidget
+from qgis.core import QgsProject
 from qgis.PyQt import uic
 
 from loopstructural.main.data_manager import default_bounding_box
@@ -13,6 +14,8 @@ def __init__(self, parent=None, data_manager=None):
         super().__init__(parent)
         ui_path = os.path.join(os.path.dirname(__file__), "bounding_box.ui")
         uic.loadUi(ui_path, self)
+
+        # Connect bounding box spinbox signals
         self.originXSpinBox.valueChanged.connect(lambda x: self.onChangeExtent({'xmin': x}))
         self.maxXSpinBox.valueChanged.connect(lambda x: self.onChangeExtent({'xmax': x}))
         self.originYSpinBox.valueChanged.connect(lambda y: self.onChangeExtent({'ymin': y}))
@@ -21,9 +24,148 @@ def __init__(self, parent=None, data_manager=None):
         self.maxZSpinBox.valueChanged.connect(lambda z: self.onChangeExtent({'zmax': z}))
         self.useCurrentViewExtentButton.clicked.connect(self.useCurrentViewExtent)
         self.selectFromCurrentLayerButton.clicked.connect(self.selectFromCurrentLayer)
+
+        # Connect CRS control signals
+        self.useProjectCrsRadioButton.toggled.connect(self.onCrsSourceChanged)
+        self.useCustomCrsRadioButton.toggled.connect(self.onCrsSourceChanged)
+        self.crsSelector.crsChanged.connect(self.onCrsChanged)
+
+        # Set up callbacks
         self.data_manager.set_bounding_box_update_callback(self.set_bounding_box)
+        self.data_manager.set_model_crs_callback(self.update_crs_ui)
+
+        # Initialize CRS UI
+        self.initialize_crs_ui()
         self._update_bounding_box_styles()
 
+        # Connect to project CRS changes so the widget updates when the project's CRS changes
+        try:
+            project = getattr(self.data_manager, 'project', None) or QgsProject.instance()
+            project.crsChanged.connect(self._onProjectCrsChanged)
+        except Exception:
+            # If the signal isn't available or connection fails, ignore to keep widget functional
+            pass
+
+    def initialize_crs_ui(self):
+        """Initialize CRS controls with current settings."""
+        # Set initial CRS selector value
+        crs = self.data_manager.get_model_crs()
+        if crs is not None and crs.isValid():
+            self.crsSelector.setCrs(crs)
+        else:
+            # Default to project CRS
+            self.crsSelector.setCrs(self.data_manager.project.crs())
+
+        # Set radio button based on use_project_crs setting
+        if self.data_manager._use_project_crs:
+            self.useProjectCrsRadioButton.setChecked(True)
+        else:
+            self.useCustomCrsRadioButton.setChecked(True)
+
+        self.validate_crs()
+
+    def onCrsSourceChanged(self):
+        """Handle change in CRS source (project vs custom)."""
+        use_project_crs = self.useProjectCrsRadioButton.isChecked()
+        self.crsSelector.setEnabled(not use_project_crs)
+
+        if use_project_crs:
+            # Use project CRS
+            success, msg = self.data_manager.set_model_crs(None, use_project_crs=True)
+        else:
+            # Use custom CRS
+            crs = self.crsSelector.crs()
+            success, msg = self.data_manager.set_model_crs(crs, use_project_crs=False)
+
+        self.validate_crs()
+
+    def onCrsChanged(self):
+        """Handle change in custom CRS selection."""
+        if self.useCustomCrsRadioButton.isChecked():
+            crs = self.crsSelector.crs()
+            success, msg = self.data_manager.set_model_crs(crs, use_project_crs=False)
+            self.validate_crs()
+
+    def update_crs_ui(self, crs, use_project_crs):
+        """Update UI when model CRS changes externally.
+
+        Parameters
+        ----------
+        crs : QgsCoordinateReferenceSystem or None
+            The new model CRS
+        use_project_crs : bool
+            Whether to use project CRS
+        """
+        # Block signals to avoid recursive updates
+        self.useProjectCrsRadioButton.blockSignals(True)
+        self.useCustomCrsRadioButton.blockSignals(True)
+        self.crsSelector.blockSignals(True)
+
+        try:
+            if use_project_crs:
+                self.useProjectCrsRadioButton.setChecked(True)
+                self.crsSelector.setEnabled(False)
+                self.crsSelector.setCrs(crs)
+
+            else:
+                self.useCustomCrsRadioButton.setChecked(True)
+                self.crsSelector.setEnabled(True)
+                if crs is not None and crs.isValid():
+                    self.crsSelector.setCrs(crs)
+
+            self.validate_crs()
+        finally:
+            # Unblock signals
+            self.useProjectCrsRadioButton.blockSignals(False)
+            self.useCustomCrsRadioButton.blockSignals(False)
+            self.crsSelector.blockSignals(False)
+
+    def _onProjectCrsChanged(self, crs=None):
+        """Handle project CRS changes and update UI when the widget is using the project CRS.
+
+        Accept an optional `crs` argument because different QGIS versions may emit the
+        new CRS or emit no arguments when the project's CRS changes.
+        """
+        # If the signal didn't provide a CRS, try to obtain it from the project's current CRS
+        if crs is None:
+            try:
+                project = getattr(self.data_manager, 'project', None) or QgsProject.instance()
+                crs = project.crs()
+            except Exception:
+                crs = None
+
+        # Only update the UI if the model is configured to use the project CRS
+        try:
+            if getattr(self.data_manager, '_use_project_crs', False):
+                # Update the UI to reflect the new project CRS
+                self.update_crs_ui(crs, use_project_crs=True)
+        except Exception:
+            pass
+
+    def validate_crs(self):
+        """Validate the selected CRS and update warning label."""
+        crs = self.data_manager.get_model_crs()
+
+        if crs is None or not crs.isValid():
+            self.crsWarningLabel.setText("⚠ Invalid CRS selected. Model cannot be initialized.")
+            return False
+
+        if crs.isGeographic():
+            # Safely get CRS description
+            try:
+                crs_desc = crs.description() or crs.authid() or "Unknown"
+            except Exception:
+                crs_desc = crs.authid() if hasattr(crs, 'authid') else "Unknown"
+
+            self.crsWarningLabel.setText(
+                f"⚠ CRS must be projected (in meters), not geographic.\n" f"Selected: {crs_desc}"
+            )
+            return False
+
+        # CRS is valid and projected
+        self.crsWarningLabel.setText("")
+        return True
+
     def set_bounding_box(self, bounding_box):
         """Populate UI controls with values from a BoundingBox object.
 

loopstructural/gui/modelling/model_definition/bounding_box.ui

@@ -162,6 +162,52 @@
      </item>
     </layout>
    </item>
+   <item>
+    <widget class="QGroupBox" name="crsGroupBox">
+     <property name="title">
+      <string>Coordinate Reference System (CRS)</string>
+     </property>
+     <layout class="QVBoxLayout" name="crsVerticalLayout">
+      <item>
+       <widget class="QRadioButton" name="useProjectCrsRadioButton">
+        <property name="text">
+         <string>Use Project CRS</string>
+        </property>
+        <property name="checked">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QRadioButton" name="useCustomCrsRadioButton">
+        <property name="text">
+         <string>Use Custom CRS</string>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QgsProjectionSelectionWidget" name="crsSelector">
+        <property name="enabled">
+         <bool>false</bool>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QLabel" name="crsWarningLabel">
+        <property name="text">
+         <string/>
+        </property>
+        <property name="wordWrap">
+         <bool>true</bool>
+        </property>
+        <property name="styleSheet">
+         <string>color: red; font-weight: bold;</string>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </widget>
+   </item>
    <item>
     <widget class="QPushButton" name="selectFromCurrentLayerButton">
      <property name="text">
@@ -185,6 +231,13 @@
    </item>
   </layout>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>QgsProjectionSelectionWidget</class>
+   <extends>QWidget</extends>
+   <header>qgis.gui</header>
+  </customwidget>
+ </customwidgets>
  <resources/>
  <connections/>
 </ui>