Clip, slice, contour and streamline filters

[doczoidberg]

Is it possible to use clip, slice, contour and streamline filters with the current implementation? What will I have to do if not?

[wschroed]

We are working on contouring now. Would you be willing to test?

[doczoidberg]

I can try. Are the other filters also planned?

[jourdain]

They are planned but I don't think we have a concrete date for when they will be available.

[agirault]

Cutter was added.

[alfredomp]

Any news on contour creation capabilities?

[jourdain]

Contour is available on vtkImageData: https://kitware.github.io/vtk-js/examples/VolumeContour.html

[alfredomp]

Thank you @jourdain . I am also interested in manual 2D contours for region selection/annotation/segmentation, are there any demos or initiatives on this?

[jourdain]

They are some initiatives but it is mostly work in progress without a clear timeline.

[jourdain]

https://thewtex.github.io/VTKWebAssemblyExperiment/

[doczoidberg]

can you tell a bit more about the webassembly integration in vtkjs? what are the plans, what is the state?

[jourdain]

@thewtex do you mind providing more inputs?

The plan is to allow users to write a piece of library in C++ that expose VTK/C++ features/algo/readers. We would provide tools to build and bundle such external lib and allow users to integrate that lib in a JS application while using vtk.js as rendering engine.

[thewtex]

Currently,

• It is possible to quickly and simply build a VTK/C++ features/algo/readers to WebAssembly. See the instructions at the bottom of this page.
• This can be used to generate a vtkPolyData ASCII file ArrayBuffer that could be read in vtk.js (untested). Or generated itk.js itk/Image could be used in vtk.js with ITKHelper.

This is the most basic functionality. There are many improvements that could be made.

• Create a vtk.js wrapper that provides SetInputConnection, SetOutputConnection algorithm interface. With a few specifications of the pipeline to run and the types of the inputs and outputs, it could provide a simplified interface that works well with the current vtk.js pipelining infrastructure. Internally, it could take care of passing the data where it needs to go and executing the pipeline. @agirault has thought about this a bit.
• We can add better support in itk.js and vtk.js for passing their native types to JavaScript/WebAssembly.
• We can work towards making the VTK WebAssembly smaller, which is important for performance.
• We can do other performance optimizations.

We are currently looking for ways to fund these improvements.