Creating a 3D B-Spline Surface and Extruded Solid with PythonOCC

Image
In the realm of 3D computer graphics and CAD (Computer-Aided Design), Python, combined with the Open CASCADE Technology (OCC) library, offers powerful tools for creating and manipulating complex geometries. One such application is the creation of a 3D B-spline surface, a versatile type of surface that can be used in various design and engineering tasks. This article will guide you through the process of creating a 3D B-spline surface using Python and OCC. Setting Up the Environment First, ensure you have the OCC library installed. This library provides the necessary tools for working with 3D geometries in Python. Our code begins with importing the required modules from the OCC library: from OCC.Core.gp import gp_Pnt, gp_Vec from OCC.Core.BRepBuilderAPI import BRepBuilderAPI_MakeFace from OCC.Core.BRepPrimAPI import BRepPrimAPI_MakePrism from OCC.Core.GeomAPI import GeomAPI_PointsToBSplineSurface from OCC.Core.TColgp import TColgp_Array2OfPnt Defining Control Points ...
Post a Comment

Creating a 3D Sinusoidal Surface with PythonOCC

Introduction

In this post, we'll delve into a fascinating example of using PythonOCC, a comprehensive Python library for 3D CAD applications. We'll create a 3D sinusoidal surface, demonstrating the power and flexibility of PythonOCC in computational geometry and CAD operations.

PythonOCC and Its Capabilities

PythonOCC, built on the OpenCASCADE Technology (OCCT), offers a wide range of tools for 3D modeling, visualization, and data exchange. It is widely used in engineering, architecture, and manufacturing for complex geometric operations and CAD data processing.

Setting Up the Environment 


import os
getcwd = os.getcwd()
path = os.path.join(getcwd, "Library\\OCC")
os.add_dll_directory(path)
Here, we import necessary libraries and add the DLL directory for OCC. This step is crucial for ensuring that the Python interpreter correctly locates the OCC dynamic link libraries.

Importing OCC Modules 


from OCC.Core.gp import gp_Pnt, gp_Vec
from OCC.Core.BRepBuilderAPI import BRepBuilderAPI_MakeFace
from OCC.Core.GeomAPI import GeomAPI_PointsToBSplineSurface
from OCC.Core.TColgp import TColgp_Array2OfPnt
import math
import random
These imports bring in classes for geometric points (gp_Pnt), B-spline surface creation (GeomAPI_PointsToBSplineSurface), and an array structure to hold the control points (TColgp_Array2OfPnt).

Defining the Surface Dimensions 


xSize, ySize = 100, 100
xSize and ySize define the grid size for the control points of our surface.

Creating the Control Points Grid 


control_points = TColgp_Array2OfPnt(1, xSize, 1, ySize)
for i in range(xSize):
    for j in range(ySize):        
        z = 3.0 * math.sin(i / 10.0) * 5.0 * math.cos(j / 10.0)
        control_points.SetValue(i+1, j+1, gp_Pnt(i, j, z))
We populate a grid with control points, where the z value at each point (i, j) is determined by a sinusoidal function.

Generating the B-Spline Surface 


surface_builder = GeomAPI_PointsToBSplineSurface(control_points)
surface = surface_builder.Surface()
A B-spline surface is created using the array of control points.

Creating a Face from the Surface 


face_builder = BRepBuilderAPI_MakeFace(surface, 1e-6)
face = face_builder.Face()
A face is constructed from the B-spline surface with a specified tolerance.

Initializing the Display and Displaying the Shape 


from OCC.Display.SimpleGui import init_display
display, start_display, add_menu, add_function_to_menu = init_display()
display.DisplayShape(face, update=True)
display.FitAll()
start_display()
We initialize the display components from PythonOCC's GUI module. Finally, the created face is displayed in a 3D viewer, fitting the view to the shape.

Result



Conclusion

This code example shows the process of creating a complex 3D surface using PythonOCC. By adjusting parameters or the mathematical function used for the z values, you can experiment with various shapes and complexities, making PythonOCC a powerful tool in 3D modeling and CAD software development. Stay tuned for more explorations into the capabilities of PythonOCC and 3D modeling!

Comments

Post a Comment

Popular posts from this blog

Creating a 3D B-Spline Surface and Extruded Solid with PythonOCC

Image
In the realm of 3D computer graphics and CAD (Computer-Aided Design), Python, combined with the Open CASCADE Technology (OCC) library, offers powerful tools for creating and manipulating complex geometries. One such application is the creation of a 3D B-spline surface, a versatile type of surface that can be used in various design and engineering tasks. This article will guide you through the process of creating a 3D B-spline surface using Python and OCC. Setting Up the Environment First, ensure you have the OCC library installed. This library provides the necessary tools for working with 3D geometries in Python. Our code begins with importing the required modules from the OCC library: from OCC.Core.gp import gp_Pnt, gp_Vec from OCC.Core.BRepBuilderAPI import BRepBuilderAPI_MakeFace from OCC.Core.BRepPrimAPI import BRepPrimAPI_MakePrism from OCC.Core.GeomAPI import GeomAPI_PointsToBSplineSurface from OCC.Core.TColgp import TColgp_Array2OfPnt Defining Control Points ...
Read more

Crafting Arc and 3D Models with PythonOCC

Image
In the realm of 3D modeling and CAD (Computer-Aided Design), PythonOCC emerges as a powerful tool, bringing the robust capabilities of Open CASCADE Technology (OCCT) to the Python environment. Let’s dive into a practical example to demonstrate how you can create intricate 3D models using PythonOCC. Setting Up Your Environment Before you begin crafting 3D models, you need to set up your environment correctly. This involves specifying the path to your OCC library and ensuring that all necessary modules are imported. Here's how you can do it: import os getcwd = os.getcwd() path = os.path.join(getcwd, "Library\OCC") os.add_dll_directory(path) This code snippet sets up the path for the DLLs required by PythonOCC, ensuring smooth execution of the modeling functions. Importing the Necessary Modules Next, we import various classes from the PythonOCC library. These classes provide functionalities for creating points, vectors, edges, wires, faces, and...
Read more

Creating a 3D prism using PythonOCC

Image
  Introduction In this tutorial, we'll delve into 3D modeling with OpenCASCADE Technology (OCC), a comprehensive CAD/CAM/CAE kernel and development platform. We will create a 3D prism based on a custom wireframe shape. Preparing the Environment Ensure you have the OCC library installed in your Python environment. This tutorial uses PythonOCC for its Python bindings to the OCC library. Step-by-Step Code Explanation Importing Necessary Modules We import classes for creating points (gp_Pnt), vectors (gp_Vec), polygons, faces, and prisms. init_display is for visualizing our 3D model. /div> Defining the Wireframe Points point_list = [ gp_Pnt(0, 0, 0), gp_Pnt(0, 10, 0), gp_Pnt(3, 28, 0), gp_Pnt(10, 10, 0), gp_Pnt(10, 0, 0), gp_Pnt(0, 0, 0) ] We define a list of points that will form our custom wireframe shape. These points will be connected in sequence to create a closed loop. Building the Wireframe Polygon polygon_builder = BRepBuilderAPI_MakeP...
Read more