VTKDataIO.jl presents a number of input, output and visualization functionalities for geometric meshes with point and cell scalar and vector data. This module attempts to bridge between VTKDataTypes.jl, Julia's native module for representing VTK data types and the Visualization Toolkit (VTK) hence giving access to many of VTK's capabilities to Julia users. VTKDataIO.jl only supports Julia v0.6.
Summary of capabilities
Input and output
You can use VTKDataIO.jl to read/write any of the following file formats into/from the corresponding type in VTKDataTypes.jl: vtk, vtu, vtp, vts, vtr, vti, vtm, pvd, stl, ply. You can do this using
Visualization and rendered output
You can use VTKDataIO.jl to visualize a scalar or vector field with a 3D heat map and a legend. This includes point-based coloring or cell based coloring, as well as other features such as wireframe and glyph representations. The resulting visualization can be written to ply or x3d formats. You can do this using
visualize_3ds can also be used to visualize 3ds files directly.
Interfacing with Python's VTK
You can use
PyVTK to change a Julia native VTK object to a VTK data PyObject that can be used in your own VTK pipeline through PyCall. You can also use
_VTKDataTypes to change a VTK data PyObject back to Julia's native VTK types.
The following are the setup steps in Windows. If you are using other OS and you can't set it up, please let me know and I will try to help if I can. Basically if you can reach step 7, you are ready to use VTKDataIO.jl even if you didn't eactly follow the previous steps!
- Get VTK on your computer. I tested it using VTK 7.1.1.
- Get Python 2.7, and add it to your PATH variable (2nd part is optional but recommended)
- Get Numpy
- Add the equivalent path to "C:\Program Files\VTK 7.1.1\bin\Lib\site-packages\vtk" to your PYTHONPATH User environment variable on your computer if you are using Windows, or the equivalent in any other OS. Basically make sure when you open a Python shell, and write
import vtkthat it works.
- Get PyCall.jl
- Find your computer's python.exe file, e.g. "C:\Python27\python.exe", and run the following 2 commands in Julia replacing the path below with your own and "\" with "\\":
ENV["PYTHON"] = "C:\\Python27\\python.exe" Pkg.build("PyCall")
- Test the following Julia code and make sure it works.
using PyCall @pyimport vtk as vtk @pyimport numpy as np
If you run the following code, you should be able to get a cubic mesh with randomly coloured cells.
using VTKDataTypes using VTKDataIO x = y = z = [-2, -1, 0, 1, 2]; rect = VTKRectilinearData([x,y,z]); rect.cell_data["Cell scalar"] = reshape([rand() for i in 1:num_of_cells(rect)], cell_extents(rect)); visualize(rect, color="Cell scalar")
You can also do point-based coloring as so:
rect.point_data["Point scalar"] = reshape([rand() for i in 1:num_of_points(rect)], extents(rect)); visualize(rect, color="Point scalar")
Point based vector data can be represented by arrows using the
rect.point_data["Point vector"] = reshape([2*rand()-1 for i in 1:3*num_of_points(rect)], (3, extents(rect)...)); visualize(rect, color="Point vector", representation=:glyph, scale_factor=0.5)
Wireframe representation can be used as follows:
visualize(rect, color="Point scalar", representation=:wireframe)
If you have the RGB colors data directly, you can inform the
visualize function to use it using the
RGB = true option as so:
rect.point_data["RGB colors"] = reshape([round(255*rand()) for i in 1:3*num_of_points(rect)], (3, extents(rect)...)); visualize(rect, color="RGB colors", RGB=true)