From 81864def9e4f185a1c4bb38dfc8c17849fdad662 Mon Sep 17 00:00:00 2001
From: Dion Moult <dion@thinkmoult.com>
Date: Sat, 28 Sep 2019 10:54:10 +1000
Subject: [PATCH] Implement support for material layer sets

---
 src/ifcblenderexport/io_export_ifc/export.py | 30 ++++++++++++++++++--
 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/src/ifcblenderexport/io_export_ifc/export.py b/src/ifcblenderexport/io_export_ifc/export.py
index e5c80e0574..11ec5401b0 100644
--- a/src/ifcblenderexport/io_export_ifc/export.py
+++ b/src/ifcblenderexport/io_export_ifc/export.py
@@ -100,6 +100,7 @@ class IfcParser():
         self.objectives = {}
         self.qtos = {}
         self.aggregates = {}
+        self.materials = {}
         self.spatial_structure_elements = []
         self.spatial_structure_elements_tree = []
         self.rel_contained_in_spatial_structure = {}
@@ -111,6 +112,7 @@ class IfcParser():
         self.rel_associates_classification_object = {}
         self.rel_associates_classification_type = {}
         self.rel_associates_material = {}
+        self.rel_associates_material_layer_set = {}
         self.rel_associates_constraint_objective_object = {}
         self.rel_associates_constraint_objective_type = {}
         self.rel_aggregates = {}
@@ -240,8 +242,12 @@ class IfcParser():
                 self.rel_associates_constraint_objective_object.setdefault(
                     object[key], []).append(product)
 
-        for slot in object.material_slots:
-            self.rel_associates_material.setdefault( slot.material.name, []).append(product)
+        if 'IsMaterialLayerSet' in object:
+            for slot in object.material_slots:
+                self.rel_associates_material_layer_set.setdefault(self.product_index, []).append(slot.material.name)
+        else:
+            for slot in object.material_slots:
+                self.rel_associates_material.setdefault( slot.material.name, []).append(product)
 
         if object.parent \
             and self.is_a_type(self.get_ifc_class(object.parent.name)):
@@ -512,8 +518,12 @@ class IfcParser():
                     continue
                 results[slot.material.name] = {
                     'ifc': None,
+                    'layer_ifc': None,
                     'raw': slot.material,
-                    'attributes': { 'Name': slot.material.name }
+                    'is_material_layer_set': True if 'IsMaterialLayerSet' in object.keys() else False,
+                    'attributes': { 'Name': slot.material.name },
+                    'layer_attributes': { key[3:]: slot.material[key] for key in
+                        slot.material.keys() if key[0:3] == 'Ifc'}
                     }
         return results
 
@@ -706,6 +716,7 @@ class IfcExporter():
         self.relate_objects_to_qtos()
         self.relate_objects_to_psets()
         self.relate_objects_to_materials()
+        self.relate_objects_to_material_layer_sets()
         self.relate_to_documents(self.ifc_parser.rel_associates_document_object)
         self.relate_to_documents(self.ifc_parser.rel_associates_document_type)
         self.relate_to_classifications(self.ifc_parser.rel_associates_classification_object)
@@ -931,6 +942,9 @@ class IfcExporter():
             material['ifc'] = self.file.createIfcMaterial(material['raw'].name, None, None)
             self.file.createIfcMaterialDefinitionRepresentation(
                 material['raw'].name, None, [styled_representation], material['ifc'])
+            if material['is_material_layer_set']:
+                material['layer_attributes']['Material'] = material['ifc']
+                material['layer_ifc'] = self.file.create_entity('IfcMaterialLayer', **material['layer_attributes'])
 
     def create_surface_style_rendering(self, material):
         surface_colour = self.create_colour_rgb(material['raw'].diffuse_color)
@@ -1222,6 +1236,16 @@ class IfcExporter():
                 [o['ifc'] for o in related_objects],
                 self.ifc_parser.materials[relating_material_key]['ifc'])
 
+    def relate_objects_to_material_layer_sets(self):
+        for product_index, related_materials in self.ifc_parser.rel_associates_material_layer_set.items():
+            material_layer_set = self.file.create_entity('IfcMaterialLayerSet', **{
+                'MaterialLayers': [self.ifc_parser.materials[m]['layer_ifc'] for m in related_materials]
+                })
+            self.file.createIfcRelAssociatesMaterial(
+                ifcopenshell.guid.new(), self.owner_history, None, None,
+                [self.ifc_parser.products[product_index]['ifc']],
+                material_layer_set)
+
     def relate_to_documents(self, relationships):
         for relating_document_key, related_objects in relationships.items():
             self.file.createIfcRelAssociatesDocument(