Immersive Direct Volume Rendering

A tool to explore volumetric data in a virutal 3 dimensional setting

binaries source documentation

Example Scene of the Immersive Direct Volume Renderer

Idea

Viewing volumetric data on a traditional 2D screen leads to an automatic loss of information. Placing volumetric data into a virtual environment allows for a more intuitive viewing, where a user can walk around the volume, grab and interact with it using their hands/controllers.

The Immersive Direct Volume Renderer is a simple, user friendly, but poverfull tool to explore volumetric data.

This project is loosely based on the paper by Kosin Kalarat, Phanit Koomhin

 

Theoretical Background

The Immersive Direct Volume Rendering tool uses a simple ray marching algorithm to sample the data. A 1D Transfer Function maps the samples to color and alpha values defined by the user.

 

Interactions

Our tool provides utilities typical for volumetric rendering but applies them to a VR setting.

 

Axis-Aligned Clipping Planes

Six Axis-Aligned Clipping Planes are attatched to the volume and the user can grab them to slice through volume and get a view of the inside.

Demonstration of the Axis-Aligned Clipping Planes

Free Volume Slicer

Additionally, we provide a Free Volume Slicer, which acts as a clipping plane, but can be grabbed with a hand and freely moved around the room.

Demonstration of the Free Volume Slicer

 

Transfer Function

The user can set which densities in the volume should be displayed with a easy to use Transfer Function.

Here, the color assossiated with the density values can be adapted as well.

Demonstration of the Alpha Panel of the Transfer FunctionDemonstration of the Alpha Panel of the Transfer Function

 

Volume Interactions

The User Interface provides elements to easily change the geometry of the volume. A small grabbable cube maps its rotation to the volume.

The user can easily change the size and global alpha value with the help of UI sliders.

 

References

This project is loosely based on the paper by Kosin Kalarat, Phanit Koomhin

REAL-TIME VOLUME RENDERING INTERACTION IN VIRTUAL REALITY

International Journal of Technology (10/7) 2019

The volumetric data was provided by the Computer Graphics Institute of the TU Vienna.