feat(configurator): server-side surface area calculation from STL

Add trimesh-based surface area calculation for uploaded STL files:
- New /fp/configurator/calculate_surface_area jsonrpc endpoint
- action_calculate_surface_area() method on fp.part.catalog
- "Calculate from 3D Model" button visible when a 3D model is attached
- Returns area in sq in (converted from mm2), vertex/face counts,
  and bounding box dimensions

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

fusion-plating/fusion_plating_configurator/__init__.py

@@ -3,4 +3,5 @@
 # License OPL-1 (Odoo Proprietary License v1.0)
 # Part of the Fusion Plating product family.
 
+from . import controllers
 from . import models

fusion-plating/fusion_plating_configurator/controllers/__init__.py

@@ -0,0 +1,2 @@
+# -*- coding: utf-8 -*-
+from . import configurator_controller

fusion-plating/fusion_plating_configurator/controllers/configurator_controller.py

@@ -0,0 +1,52 @@
+# -*- coding: utf-8 -*-
+# Copyright 2026 Nexa Systems Inc.
+# License OPL-1 (Odoo Proprietary License v1.0)
+# Part of the Fusion Plating product family.
+
+import base64
+import io
+import logging
+
+from odoo import http
+from odoo.http import request
+
+_logger = logging.getLogger(__name__)
+
+
+class FpConfiguratorController(http.Controller):
+
+    @http.route('/fp/configurator/calculate_surface_area', type='jsonrpc', auth='user')
+    def calculate_surface_area(self, attachment_id, **kw):
+        """Calculate surface area from an uploaded STL file using trimesh."""
+        attachment = request.env['ir.attachment'].browse(int(attachment_id))
+        if not attachment.exists():
+            return {'error': 'Attachment not found.'}
+
+        try:
+            import trimesh
+        except ImportError:
+            return {'error': 'trimesh library not installed. Run: pip install trimesh'}
+
+        try:
+            raw = base64.b64decode(attachment.datas)
+            mesh = trimesh.load(io.BytesIO(raw), file_type='stl')
+
+            # trimesh returns area in the file's native units (usually mm²)
+            area_mm2 = mesh.area
+            area_sqin = area_mm2 / 645.16  # mm² to sq in
+
+            return {
+                'surface_area': round(area_sqin, 4),
+                'surface_area_mm2': round(area_mm2, 2),
+                'unit': 'sq_in',
+                'vertex_count': len(mesh.vertices),
+                'face_count': len(mesh.faces),
+                'bounding_box': {
+                    'x': round(float(mesh.bounding_box.extents[0]), 2),
+                    'y': round(float(mesh.bounding_box.extents[1]), 2),
+                    'z': round(float(mesh.bounding_box.extents[2]), 2),
+                },
+            }
+        except Exception as e:
+            _logger.warning('STL surface area calculation failed: %s', e)
+            return {'error': str(e)}

fusion-plating/fusion_plating_configurator/models/fp_part_catalog.py

@@ -3,7 +3,7 @@
 # License OPL-1 (Odoo Proprietary License v1.0)
 # Part of the Fusion Plating product family.
 
-from odoo import fields, models
+from odoo import api, fields, models, _
 
 
 class FpPartCatalog(models.Model):
@@ -63,3 +63,39 @@ class FpPartCatalog(models.Model):
         ('fp_part_catalog_partner_partnum_uniq', 'unique(partner_id, part_number)',
          'Part number must be unique per customer.'),
     ]
+
+    def action_calculate_surface_area(self):
+        """Calculate surface area from the uploaded 3D model file."""
+        self.ensure_one()
+        if not self.model_attachment_id:
+            from odoo.exceptions import UserError
+            raise UserError(_('No 3D model file uploaded.'))
+
+        try:
+            import trimesh
+        except ImportError:
+            from odoo.exceptions import UserError
+            raise UserError(_('trimesh library not installed on the server. Contact your administrator.'))
+
+        import base64
+        import io
+
+        raw = base64.b64decode(self.model_attachment_id.datas)
+        mesh = trimesh.load(io.BytesIO(raw), file_type='stl')
+        area_mm2 = mesh.area
+        area_sqin = area_mm2 / 645.16
+
+        self.surface_area = round(area_sqin, 4)
+        self.surface_area_uom = 'sq_in'
+        self.geometry_source = '3d_model'
+
+        return {
+            'type': 'ir.actions.client',
+            'tag': 'display_notification',
+            'params': {
+                'title': _('Surface Area Calculated'),
+                'message': _('%.4f sq in (%.2f mm\u00b2) from %d faces') % (area_sqin, area_mm2, len(mesh.faces)),
+                'type': 'success',
+                'sticky': False,
+            },
+        }

fusion-plating/fusion_plating_configurator/views/fp_part_catalog_views.xml

@@ -44,7 +44,14 @@
                             <field name="geometry_source"/>
                         </group>
                         <group>
-                            <field name="surface_area"/>
+                            <label for="surface_area"/>
+                            <div class="d-flex align-items-center gap-2">
+                                <field name="surface_area" class="oe_inline"/>
+                                <button name="action_calculate_surface_area" type="object"
+                                        string="Calculate from 3D Model"
+                                        class="btn-link" icon="fa-calculator"
+                                        invisible="not model_attachment_id"/>
+                            </div>
                             <field name="surface_area_uom"/>
                             <field name="weight"/>
                         </group>