style.add_surface_texture to work without blender material provided

src/ifcopenshell-python/ifcopenshell/api/style/add_surface_textures.py

@@ -21,10 +21,8 @@ import ifcopenshell.api
 
 
 class Usecase:
-    def __init__(self, file, material=None, uv_maps=None):
-        """Add a surface texture based on a Blender material definition
-
-        Warning: this API can only be used with Blender data structures.
+    def __init__(self, file, material=None, uv_maps=None, textures=None):
+        """Add surface texture based on a Blender material definition or texture data.
 
         :param material: The Blender material definition with a node tree that
             is compatible with glTF. See one of the valid combinations here:
@@ -34,12 +32,26 @@ class Usecase:
             IfcTessellatedFaceSets that the representation has, obtained from
             the HasTextures attribute.
         :type uv_maps: list[ifcopenshell.entity_instance.entity_instance]
+        :param textures: A list of dictionaries containing:
+
+            1. Attributes to create IfcImageTexture.
+            2. One additional parameter `uv_mode` to map IfcImageTexture to correct
+               IfcTextureCoordinate type.
+
+            Possible `uv_mode` values:
+
+            * `UV` - use IfcTextureCoordinate from `uv_maps` parameter;
+            * `Generated` - IfcTextureCoordinateGenerator with mode COORD (autogenerated UV
+              based on geometry);
+            * `Camera` - IfcTextureCoordinateGenerator with mode COORD_EYE (autogenerated UV
+              based on camera position)
+        :type textures: list[dict]
         :return: A list of IfcImageTexture
         :rtype: list[ifcopenshell.entity_instance.entity_instance]
         """
         # TODO: This usecase currently depends on Blender's data model
         self.file = file
-        self.settings = {"material": material, "uv_maps": uv_maps or []}
+        self.settings = {"material": material, "uv_maps": uv_maps or [], "textures": textures or []}
 
     def execute(self):
         if self.file.schema == "IFC2X3":
@@ -51,6 +63,23 @@ class Usecase:
         # glTF, X3D, and IFC are compatible. As long as they have something that
         # loosely resembles the node tree, we treat it as valid.
         self.textures = []
+
+        for texture in self.settings["textures"]:
+            uv_mode = texture.get("uv_mode", None)
+            texture_data = texture.copy()
+            texture_data.pop("uv_mode", None)
+            texture = self.file.create_entity("IfcImageTexture", **texture_data)
+            if uv_mode == "Generated":
+                self.file.create_entity("IfcTextureCoordinateGenerator", Maps=[texture], Mode="COORD")
+            elif uv_mode == "Camera":
+                self.file.create_entity("IfcTextureCoordinateGenerator", Maps=[texture], Mode="COORD-EYE")
+            elif uv_mode == "UV":
+                self.apply_uv_map_to_texture(texture)
+            self.textures.append(texture)
+
+        if self.settings["material"] is None:
+            return self.textures
+
         output = {n.type: n for n in self.settings["material"].node_tree.nodes}.get("OUTPUT_MATERIAL", None)
 
         if not output:
@@ -73,6 +102,7 @@ class Usecase:
             self.detect_occlusion_map()
             self.detect_diffuse_map(bsdf)
         # We do not support Phong shading. What year is this, 1995?
+
         return self.textures
 
     def detect_unlit_emissive_map(self, bsdf):

src/ifcopenshell-python/test/api/style/test_add_surface_textures.py

@@ -0,0 +1,80 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2022 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import pytest
+import test.bootstrap
+import ifcopenshell.api
+
+
+class TestAddSurfaceTexture(test.bootstrap.IFC4):
+    def get_default_texture_data(self):
+        return [
+            {"Mode": "DIFFUSE", "RepeatS": True, "RepeatT": True, "URLReference": "diffuse.jpg"},
+            {"Mode": "NORMAL", "RepeatS": False, "RepeatT": False, "URLReference": "normal.jpg"},
+            {"Mode": "METALLICROUGHNESS", "RepeatS": True, "RepeatT": True, "URLReference": "metallic_roughness.jpg"},
+            {"Mode": "OCCLUSION", "RepeatS": True, "RepeatT": True, "URLReference": "ambient_occlusion.jpg"},
+        ]
+
+    def compare_texture_to_data(self, texture, data, uv_maps=[]):
+        texture_data = texture.get_info()
+        for attribute in ("Mode", "RepeatS", "RepeatT", "URLReference"):
+            assert texture_data[attribute] == data.get(attribute, None)
+
+        uv_mode = data.get("uv_mode", None)
+        if uv_mode is None:
+            assert texture.IsMappedBy == ()
+        elif uv_mode == "Generated":
+            assert len(texture.IsMappedBy) == 1
+            assert texture.IsMappedBy[0].Mode == "COORD"
+        elif uv_mode == "Camera":
+            assert len(texture.IsMappedBy) == 1
+            assert texture.IsMappedBy[0].Mode == "COORD-EYE"
+        elif uv_mode == "UV":
+            assert set(texture.IsMappedBy) == set(uv_maps)
+
+    def test_add_surface_textures_from_data(self):
+        texture_data = self.get_default_texture_data()
+
+        textures = ifcopenshell.api.run("style.add_surface_textures", self.file, textures=texture_data)
+        assert len(list(self.file)) == len(texture_data)
+
+        for texture, data in zip(textures, texture_data):
+            self.compare_texture_to_data(texture, data)
+
+    def test_add_surface_textures_from_data_with_uv_mode(self):
+        texture_data = self.get_default_texture_data()
+        texture_data[0]["uv_mode"] = "Generated"
+        texture_data[1]["uv_mode"] = "Camera"
+        texture_data[2]["uv_mode"] = "UV"
+        texture_data[3]["uv_mode"] = None
+
+        textures = ifcopenshell.api.run("style.add_surface_textures", self.file, textures=texture_data)
+        for texture, data in zip(textures, texture_data):
+            self.compare_texture_to_data(texture, data)
+
+    def test_add_surface_textures_from_data_with_uv_maps(self):
+        texture_data = self.get_default_texture_data()
+        texture_data[0]["uv_mode"] = "Generated"
+        texture_data[1]["uv_mode"] = "Camera"
+        texture_data[2]["uv_mode"] = "UV"
+        texture_data[3]["uv_mode"] = None
+
+        uv_maps = [self.file.create_entity("IfcTextureCoordinateGenerator", Maps=[], Mode="COORD") for i in range(5)]
+        textures = ifcopenshell.api.run("style.add_surface_textures", self.file, textures=texture_data, uv_maps=uv_maps)
+        for texture, data in zip(textures, texture_data):
+            self.compare_texture_to_data(texture, data, uv_maps)