@Moult said:
This would be great to share on social media! By the way, IfcGridPlacement would be how to link objects to a grid's placement. However, it is not supported in IfcOpenShell.
Any news on it? I believe, I can create IfcGridPlacement instead of IfcLocalPlacement and use it for IfcBuilding placement in ifcopenshell. But BlenderBIM couldn't load such IFC:
Well, I think I’ve found solution for myself. Just threw some middle-school equations in and now finding axes intersections explicitly:
def find_axes_intersection(a1, a2):
p11 = a1.AxisCurve.Points[0]
p12 = a1.AxisCurve.Points[1]
p21 = a2.AxisCurve.Points[0]
p22 = a2.AxisCurve.Points[1]
z0 = p11.Coordinates[2]
x11 = p11.Coordinates[0]
x12 = p12.Coordinates[0]
y11 = p11.Coordinates[1]
y12 = p12.Coordinates[1]
x21 = p21.Coordinates[0]
x22 = p22.Coordinates[0]
y21 = p21.Coordinates[1]
y22 = p22.Coordinates[1]
A1 = y12 - y11
B1 = x12 - x11
C1 = y11 * (x12 - x11) - x11 * (y12 - y11)
A2 = y22 - y21
B2 = x22 - x21
C2 = y21 * (x22 - x21) - x21 * (y22 - y21)
x0 = (B1 * C2 - B2 * C1) / (A1 * B2 - A2 * B1)
y0 = (C1 * A2 - C2 * A1) / (A1 * B2 - A2 * B1)
return [x0,y0,z0]
def create_customgridplacement(axis1, axis2, dir1=globalAxisZ, dir2=globalAxisX):
point = ifc.createIfcCartesianPoint(find_axes_intersection(axis1, axis2))
axis2Placement = ifc.createIfcAxis2Placement3D(point, dir1, dir2)
localPlacement = ifc.createIfcLocalPlacement(None, axis2Placement)
return localPlacement
When opening the IFC the Grids are contained to the site, from models exported from different sources I always see them related to the building storey, is there a reason why you've chosen to relate it to the site?
@Pahlawan
is there a reason why you've chosen to relate it to the site?
No specific reason, intuivitely seemed to be the most logic place.
@Coen said:
@Pahlawan
is there a reason why you've chosen to relate it to the site?
No specific reason, intuivitely seemed to be the most logic place.
Yeah also seems to work good if you add other models in for example Solibri the grids will be there on multiple floors if that model has elements on that floor. Strangely does not work when there are only slabs in the model, it’ll only project on the first floor. Don’t know if that’s a feature or a bug though.
Python code for create ifcGrid direct on BlenderBIM
"""
#bpy.ops.bim.new_project(preset="metric_mm")
Test_Create_Grid_01.py
"""
import bpy
import blenderbim.tool as tool
import ifcopenshell
from mathutils import Vector
site = tool.Ifc.get().by_type("IfcSite")
site = site[0]
site_obj = tool.Ifc.get_object(site)
obj = bpy.data.objects.new("Grid", None)
obj.name = "Grid"
collection = site_obj.BIMObjectProperties.collection
collection.objects.link(obj)
bpy.ops.bim.assign_class(obj=obj.name, ifc_class="IfcGrid")
grid = tool.Ifc.get_entity(obj)
collection = obj.BIMObjectProperties.collection
GridXList = [ {'id':'1' , 'distance':0.0 } ,
{'id':'2' , 'distance':4 },
{'id':'3' , 'distance':7 }, ]
GridYList = [ {'id':'A' , 'distance':0.0 } ,
{'id':'B' , 'distance':3.5 },
{'id':'C' , 'distance':5.5 },
{'id':'D' , 'distance':9.5},]
common_keys = set.intersection(*map(set, GridXList))
v = {k: [dic[k] for dic in GridXList] for k in common_keys}
maxX = max(v['distance'])
minX = min(v['distance'])
common_keys = set.intersection(*map(set, GridYList))
v = {k: [dic[k] for dic in GridYList] for k in common_keys}
maxY = max(v['distance'])
minY = min(v['distance'])
axes_collection1 = bpy.data.collections.new("UAxes")
collection.children.link(axes_collection1)
for iGrid in GridYList:
id = iGrid['id']
y = iGrid['distance']
verts = [
Vector(( minX-2, y ,0)),
Vector(( maxX+2, y ,0)),
]
print(verts)
edges = [[0, 1]]
faces = []
mesh = bpy.data.meshes.new(name="Grid Axis")
mesh.from_pydata(verts, edges, faces)
tag = id
obj = bpy.data.objects.new(f"IfcGridAxis/{tag}", mesh)
axes_collection1.objects.link(obj)
result = ifcopenshell.api.run(
"grid.create_grid_axis",
tool.Ifc.get(),
**{"axis_tag": tag, "uvw_axes": "UAxes", "grid": grid},
)
tool.Ifc.link(result, obj)
ifcopenshell.api.run("grid.create_axis_curve", tool.Ifc.get(), **{"axis_curve": obj, "grid_axis": result})
obj.BIMObjectProperties.ifc_definition_id = result.id()
axes_collection2 = bpy.data.collections.new("VAxes")
collection.children.link(axes_collection2)
for iGrid in GridXList:
id = iGrid['id']
x = iGrid['distance']
verts = [
Vector(( x , minY-2, 0)),
Vector(( x , maxY+2, 0)),
]
print(verts)
edges = [[0, 1]]
faces = []
mesh = bpy.data.meshes.new(name="Grid Axis")
mesh.from_pydata(verts, edges, faces)
tag = id
obj = bpy.data.objects.new(f"IfcGridAxis/{tag}", mesh)
axes_collection2.objects.link(obj)
result = ifcopenshell.api.run(
"grid.create_grid_axis",
tool.Ifc.get(),
**{"axis_tag": tag, "uvw_axes": "VAxes", "grid": grid},
)
tool.Ifc.link(result, obj)
ifcopenshell.api.run("grid.create_axis_curve", tool.Ifc.get(), **{"axis_curve": obj, "grid_axis": result})
obj.BIMObjectProperties.ifc_definition_id = result.id()
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