Parametric design with Python

This page describes parametric design in XFEM4U, and how to create 3D models using Python. The resulting models can be sent to Speckle or to XFEM4U.

Example files are available on the Struct4U GitHub repository.

Direct Commands

XFEM4U and XFrame2D provide a function called DirectCommands. You can use DirectCommands to open XFEM4U and XFrame2D from an external program such as Excel or Python.

Python

This example creates a 3D model in XFEM4U using Python. It uses the open source Python interpreter PyCharm Community Edition.

The script relies on the open source library BuildingPy, which provides classes such as point, vector, line, polycurve, panel, beam, support and loads. The 3D model is built from objects of these classes.

Example

from bp_single_file import *
# bp_single_file is a single pythonfile required to create the 3D-model in XFEM4U.
# There is a dependency on Numpy.

project = BuildingPy("Struct4U Example file", "0")
# create a project with a name and project number

height = 3000
# In this case the height is a variable in this structure

# CREATE GRIDSYSTEM
gridinput = ["0 1000 1000", seqChar, "0 4x3600", seqNumber, "0"]
# This is the syntax for a gridsystem. It is the same syntax used in XFEM4U.

# CONCRETE BEAM
project.objects.append(Frame.byStartpointEndpoint(Point(0,0,0), Point(0,14400,0), Rectangle("350x500",350,500).curve, "350x500", 0, BaseConcrete))
project.objects.append(Frame.byStartpointEndpoint(Point(0,14400,0), Point(2000,14400,0), Rectangle("350x500",350,500).curve, "350x500", 0, BaseConcrete))
# Here we create 2 rectangular concrete beams, using coordinates and profiles.

# STEEL COLUMN
project.objects.append(Frame.byStartpointEndpointProfileNameShapevector(Point(2000,14400,0), Point(2000,14400,height), "HEA160", "HEA160", Vector2(0,0), 0, BaseSteel, "Frame"))
# Here we create a steel column. For a HEA160 you can use the syntax 'HEA 160', 'HE160A', 'hea 280' etc.
# Other steel profiles are HEB100, HEM100, IPE100, 100AA, HD260/54,1, DIN, DIE, DIR, DIL, UNP, B42.4/2.6, INP.
# For the full list of profiles see:
# https://github.com/3BMLabs/building.py/blob/main/library/profile_database/steelprofile.json
# Composite profiles are not yet implemented.

# STEEL FRAMES
x = 1000
y = 0
for i in range(5):
    project.objects.append(Frame.byStartpointEndpointProfileNameShapevector(Point(0,y,0), Point(0,y,height), "HEA180", "HEA180", Vector2(0,0), 90, BaseSteel, "Frame"))     # column
    project.objects.append(Frame.byStartpointEndpointProfileNameShapevector(Point(0,y,height), Point(x,y,height), "HEA180", "HEA180", Vector2(0,0), 0, BaseSteel, "Frame")) # beam
    x = x + 250
    y = y + 3600
# In this for loop we create the frames. The x and y coordinates increase with every step in the loop.

# PLATE IN XFEM4U
project.objects.append(Panel.byPolyCurveThickness(
    PolyCurve.byPoints(
        [Point(0,0,height),
         Point(0,14400,height),
         Point(2000,14400,height),
         Point(1000,0,height),
         Point(0,0,height)]),
    100,
    0,
    "Plate",
    BaseConcrete.colorint))
# The code above creates a plate based on 5 coordinates. The plate has a thickness.

# SEND PROJECT TO SPECKLE
# project.toSpeckle("31d9948b31")
# It is possible to visualize the result of this parametric structure in Speckle.

# CREATE XML-FILE
pathxml = "C:/TEMP/test4.xml"
# This is the path where the temporary file is saved.

createXFEM4UXML(project, pathxml, gridinput)
# We create an XML to load into XFEM4U.

OpenXMLXFEM4U(pathxml)
# This function will activate XFEM4U and open the parametric model.

See also

• XML - the XML format this script writes