Paraview + Volume Rendering tutorial


Volume rendering is a technique for visualizing 3D datasets, such as MRI or CT scans. In this tutorial, we'll be looking at two pieces of software for visualizing volumetric data: Paraview and Ben's Volume Renderer. Paraview is a popular application for scientific data visualization, which supports a wide variety of data formats and rendering algorithms. Ben's volume renderer is a volume renderer for HMDs that was created by Ben Knorlein.  Ben's volume renderer supports a variety of data formats (e.g. NRRD files and TIFF image stacks) and colormaps, as well as multi-user collaboration. 

First, you'll look at the process of rendering volumetric data in Paraview. Then, you'll look at how volumetric rendering works in Ben's Volume Renderer.

Volume Rendering in Paraview

Estimated time: 20-30 minutes


In this section of the tutorial, you'll be visualizing a CT scan of a rat heart vessel in Paraview. Note that you should complete this section of the tutorial by yourself.


Note: Complete the following steps on your Paperspace Machine. 

Visualizing the Rat Heart

This tutorial will demonstrate how to visualize sample density (.vtk file here). 

6. We can also change the color scheme and each color's range in the data. To do this, click the Edit button under Coloring.

7. Under the Information tab (on left side next to properties), we can get learn more about the data, including the size of the dataset, the data ranges, and data type. 

8. In the third row of the top section, there are various cube icons that help us alter and further analyze a volume, including contour (surface rendering), slicing (cutting a plane from the data set), and clipping (cutting a section of the dataset). Experiment with these functions!

If these appear greyed out, try pressing the Apply button under Properties.

9. Choose a visualization to view in VR. Then connect your headset to your machine using Remote Desktop. 

10. Once connected, open the Tools dropdown of the upper left menu in Paraview from your desktop and select Manage Plugins.

10. Scroll down to the OpenVR plugin, click on it, and select load plugin.

11. Click the Send to OpenVR button in the left menu.

11. Put on your headset again. You should now see your visualization in VR. Take a screenshot of it and post it to the class board.


Hold both side triggers and push them towards/away from each other to move the visualization up/down. 

Some example visualizations from past years: 

Credit: Alejandro Romero (Spring 2021)

Ben's Volume Renderer

Estimated time: 40 minutes

Requirements:  Windows 10*, SteamVR, and Visual Studio Community 2019 (or later versions).


In this section of the tutorial, you'll be visualizing three different datasets: 

You'll be visualizing these datasets with a partner, which will be given at the beginning of class. Note that the volume renderer implements controller-viewer collaboration, in which one user -- the controller -- performs actions while the other users -- the viewers -- spectate. Practically speaking, this means that you and your partner will have to take turns as the controller. 


While working through this section of the tutorial, complete the following objectives:



Starting the Volume Renderer

Volume Renderer Controls

Ben's Volume Renderer supports a variety of controls that utilize both the Oculus Quest controllers and a menu. While working on the above objectives, you'll likely want to view these controls in your headset. This can be done launching the SteamVR menu (click the button with three bars on the left Oculus controller) and selecting Desktop from left panel of the SteamVR menu. 

Quest 2 Controller Controls

Menu Controls

The menu in the Volume Renderer allows you to customize the appearance of the rendered model. Here is a brief description of what each option does: