Fix #3355. Reimplement graphical clash snapshots in BCF from IfcClash in the BlenderBIM Add-on.

src/bcf/src/bcf/v2/topic.py

@@ -275,6 +275,7 @@ class TopicHandler:
         """
         new_viewpoint = VisualizationInfoHandler.create_new(element, self._xml_handler)
         self.add_visinfo_handler(new_viewpoint)
+        return new_viewpoint
 
     def add_viewpoint_from_point_and_guids(self, position: NDArray[np.float_], *guids: str) -> None:
         """Add a viewpoint pointing at an XYZ point in space
@@ -287,6 +288,7 @@ class TopicHandler:
             position, *guids, xml_handler=self._xml_handler
         )
         self.add_visinfo_handler(vi_handler)
+        return vi_handler
 
     def add_visinfo_handler(self, new_viewpoint: VisualizationInfoHandler) -> None:
         self.viewpoints[new_viewpoint.guid + ".bcfv"] = new_viewpoint

src/blenderbim/blenderbim/bim/module/clash/operator.py

@@ -23,7 +23,7 @@ import bmesh
 import logging
 import numpy as np
 import ifcopenshell
-from mathutils import Matrix
+from mathutils import Matrix, Vector
 from math import radians
 from blenderbim.bim.ifc import IfcStore
 
@@ -222,6 +222,7 @@ class ExecuteIfcClash(bpy.types.Operator):
         _, extension = os.path.splitext(self.filepath)
         if extension != ".json":
             self.filepath = bpy.path.ensure_ext(self.filepath, ".bcf")
+
         settings = ifcclash.ClashSettings()
         settings.output = self.filepath
         settings.logger = logging.getLogger("Clash")
@@ -230,12 +231,28 @@ class ExecuteIfcClash(bpy.types.Operator):
 
         if context.scene.BIMClashProperties.should_create_clash_snapshots:
 
-            def get_viewpoint_snapshot(viewpoint, mat):
+            def get_viewpoint_snapshot(viewpoint):
                 camera = bpy.data.objects.get("IFC Clash Camera")
                 if not camera:
                     camera = bpy.data.objects.new("IFC Clash Camera", bpy.data.cameras.new("IFC Clash Camera"))
                     context.scene.collection.objects.link(camera)
-                camera.matrix_world = Matrix(mat)
+
+                bcf_camera = viewpoint.visualization_info.perspective_camera
+                p = bcf_camera.camera_view_point
+                z = bcf_camera.camera_direction
+                z = Vector([z.x, z.y, z.z]) * -1
+                y = bcf_camera.camera_up_vector
+                y = Vector([y.x, y.y, y.z])
+                x = y.cross(z)
+
+                mat = Matrix([
+                    [x[0], y[0], z[0], p.x],
+                    [x[1], y[1], z[1], p.y],
+                    [x[2], y[2], z[2], p.z],
+                    [0, 0, 0, 0],
+                ])
+
+                camera.matrix_world = mat
                 context.scene.camera = camera
                 camera.data.angle = radians(60)
                 area = next(area for area in context.screen.areas if area.type == "VIEW_3D")
@@ -246,7 +263,8 @@ class ExecuteIfcClash(bpy.types.Operator):
                 context.scene.render.image_settings.file_format = "PNG"
                 context.scene.render.filepath = os.path.join(context.scene.BIMProperties.data_dir, "snapshot.png")
                 bpy.ops.render.opengl(write_still=True)
-                return context.scene.render.filepath
+                with open(context.scene.render.filepath, "rb") as f:
+                    return ("snapshot.png", f.read())
 
             clasher.get_viewpoint_snapshot = get_viewpoint_snapshot
 

src/ifcclash/ifcclash/ifcclash.py

@@ -122,14 +122,20 @@ class Clasher:
             for clash in clash_set["clashes"].values():
                 title = f'{clash["a_ifc_class"]}/{clash["a_name"]} and {clash["b_ifc_class"]}/{clash["b_name"]}'
                 topic = bcfxml.add_topic(title, title, "IfcClash")
-                topic.add_viewpoint_from_point_and_guids(
+                viewpoint = topic.add_viewpoint_from_point_and_guids(
                     np.array(clash["position"]), clash["a_global_id"], clash["b_global_id"],
                 )
+                snapshot = self.get_viewpoint_snapshot(viewpoint)
+                if snapshot:
+                    topic.markup.viewpoints[0].snapshot = snapshot[0]
+                    viewpoint.snapshot = snapshot[1]
             suffix = f".{i}" if i else ""
             bcfxml.save_project(f"{self.settings.output}{suffix}")
 
-    def get_viewpoint_snapshot(self, viewpoint, mat):
-        return None  # Possible to overload this function in a GUI application if used as a library
+    def get_viewpoint_snapshot(self, viewpoint):
+        # Possible to overload this function in a GUI application if used as a library.
+        # Should return a tuple of (filename, bytes).
+        return None
 
     def export_json(self):
         clash_sets = self.clash_sets.copy()