ActiViz 9.7 Release

September 4, 2026

Lucas Gandel, Julien Finet and Alexy Pellegrini

Kitware is pleased to announce the release of ActiViz 9.7.2026.727, the latest version of Kitware’s .NET/C# wrapper for the Visualization Toolkit (VTK). In addition to the key improvements provided by VTK 9.7.0, this release significantly enhances support for the Avalonia framework, pushing the boundaries of cross-platform Graphical User Interface (GUI) integration.

ActiViz

ActiViz is a .NET wrapper for the Visualization Toolkit (VTK) that enables advanced 2D and 3D scientific visualization capabilities to be used in C# and other .NET applications.

ActiViz interfaces with a wide range of Graphical User Interface (GUI) frameworks, including Windows Forms, Windows Presentation Foundation (WPF), WinUI, Avalonia, and the Unity software. It allows developers to quickly develop production-ready, interactive 3D applications in the .NET environment, now including web browsers.

For concrete examples, please see Activiz in Action.

VTK 9.7.0

Based on VTK 9.7.0, this new ActiViz version delivers high-performance processing improvements, enhanced rendering capabilities, and numerous bug fixes. Watch the What’s new in VTK 9.7 webinar for more information.

Avalonia 12

Building on the enhanced integration of VTK with Avalonia‘s rendering lifecycle introduced in the previous release, the ActiViz Avalonia rendering control has been completely redesigned to support the latest major version of Avalonia. By overcoming the challenge of managing VTK rendering resources within an OpenGL context owned by Avalonia, the new control enables seamless integration of advanced VTK visualizations into modern cross-platform GUI applications.

The control integrates naturally with native Avalonia components, allowing developers to create rich, responsive user interfaces that fully leverage VTK’s advanced visualization capabilities.

Advanced VTK visualization embedded in an Avalonia application for interactive aerodynamic simulation and analysis of cycling performance. (Model based on “Cycle Helmet” by markchester licensed under CC-BY-4.0)

Interlacing VTK and SkiaSharp rendering

SkiaSharp is a cross-platform 2D graphics API for .NET platforms based on Google’s Skia Graphics Library and used by Avalonia to render UI components. The new ActiViz rendering control leverages offscreen rendering of the VTK scene into the Skia canvas presented by Avalonia. This approach enables VTK and Skia rendering commands to be seamlessly interleaved, making it possible to combine 3D visualization with custom 2D graphics and advanced visual effects such as magnifying glasses, glassmorphism overlays, and animated progress gauges.

To simplify the integration of VTK and SkiaSharp, the ActiViz Avalonia RenderWindowControl exposes two Action<SKCanvas> delegates to issue Skia rendering commands immediately before and after the VTK rendering pass. The example below demonstrates how to use these actions to create simple visual effects.

// PreRender action called before VTK rendering pass
// Clear background before rendering VTK
renderWindowControl.PreRender = (SKCanvas canvas) => {
  canvas.Clear(SKColors.DarkGray)
};

// PostRender action called after VTK rendering pass.
// Render a blurred version of VTK's framebuffer
renderWindowControl.PostRender = (SKCanvas canvas) => {
  using var snapshot = canvas.Surface?.Snapshot();
  using var blurPaint = new SKPaint
  {
    ImageFilter = SKImageFilter.CreateBlur(12, 12)
  };
  canvas.DrawImage(snapshot, 0, 0, blurPaint);
};

Support and Services

Request a trial version of ActiViz by filling out the form on the ActiViz website. Our team is available to support integration efforts, assist with feature adoption, and help tailor ActiViz to your application’s needs. Contact us if you would like to learn more about ActiViz or discuss how Kitware can support your project.