CAID is a multi-platform software that has been designed for IsoGeometric Analysis Pre and Post Processing. Its design goal is to provide a fast, light and user-friendly designer and meshing tool.

The Post-Processing and advanced visualization capabilities are still under development, as well as an optimized 3D computing engine.

For more details, please read [CAID](http://ratnani.org/caid_doc/)

CAID can be used in 2 different ways:

• as a python package: using ipython or scripts
• as a GUI modeler: for a better interactive use

In order to follow related developments to CAID, please visit our JOREK-Django project on (https://tree.taiga.io/project/ratnani-jorek-django/)

• Python3 interpreter (https://docs.python.org/3):

  sudo apt-get install python3 python3-dev

• pip package manager for Python (https://pypi.python.org/pypi/pip):

  sudo apt-get install python3-pip

• Python dependencies (Numpy, Scipy, Matplotlib) can be installed using:

  python3 -m pip install --user -r requirements.txt

• igakit (http://bitbucket.org/dalcinl/igakit) is a Python package that implements many of the NURBS routines from Piegl's book using Fortran and Python:

  python3 -m pip install --user hg+https://bitbucket.org/dalcinl/igakit

• wxPython (https://wxpython.org), a cross-platform GUI toolkit for the Python language.

  To install on Windows and Mac OS X:

  python3 -m pip install --user wxPython

  To install on Linux, correct binaries must be selected depending on distribution (check availability at https://extras.wxpython.org/wxPython4/extras/linux/gtk3). For example:

  python3 -m pip install --user -f https://extras.wxpython.org/wxPython4/extras/linux/gtk3/ubuntu-16.04 wxPython

• PyOpenGL (http://pyopengl.sourceforge.net/), the most common cross platform Python binding to OpenGL and related APIs:

  python3 -m pip install --user PyOpenGL PyOpenGL_accelerate

• Standard mode:

  python3 -m pip install --user .

• Developer mode:

  python3 -m pip install --user -e .

Start by import the CAID package:

import caid

In order to check that the fortran code has been well installed, use:

import caid.core
import caid.core.bspline
import caid.core.hbezier

If you don't get any message, then everything seems to be fine.

Let's now import a square geometry and refine it:

from caid.cad_geometry import square
geo = square(n=[3,3], p=[2,2])
geo.plotMesh()
import matplotlib.pyplot as plt
plt.show()

A cad_geometry object contains a list of cad_nurbs (more generally any class that inherits from the cad_object class) with some additional informations. The class cad_nurbs inherits the NURBS class in igakit. It represents a single patch but with some additional informations like

• orientation: needed for Neumann boundary conditions
• rational: True if we use the weights. Default value : False

In the future, the cad_geometry class will also contain Splines on triangulations (using splitri)

Add the following lines in your .bashrc/.bash_profile by replacing PATH_TO_CAID_SRC with the correct path to the project source directory:

alias caid="python3 $PATH_TO_CAID_SRC/caid-gui/main.py"

Running CAID can be done in different ways.

• without any argument

  caid

• with a given workgroup session

  caid session.wkl

• with given domains files session

  caid domain1.xml domain2.xml domain3.xml

• with a given field file

  caid U.pfl

• update setup file, using pip to install all dependencies.