Volumevis is a software that renders 3D datasets using pixels.
In today's world, most 3-dimensional visualization is based on surfaced-based visualization, which is also true for most 3D games, CAD tools, etc. At its core, surface-based rendering divides a surface into small triangles and sends those triangles with their color to a graphics card for rendering. To render a sphere in 3D, for instance, the surface of the sphere is created, divided into triangles and then sent to the graphics card. The graphics card turns the triangles into pixels, which are then displayed.
The disadvantage of surface-based visualization, however, is the inability to see inside or beyond the surface. Because of this, volume visualization is the equivalent of displaying a 3D photo. The volume visualization technique used by Volumevis allows for the display of information that goes beyond the surface representation. Volumevis uses all fragments (3D-equivalent of pixels) with an alpha value for opacity. This alpha value determines the fragment's transparency such that the smaller the alpha value, the easier it is to see through the fragment and see fragments located behind it.
During the visualization process, a 3D dataset appears like a block of data in the shape of a cube. Within the cube, there's an object which is white or grey. All other places in the image are black. Pixels that are black in color are assigned an alpha value of 0 (i.e., transparent) to render the object visible. The fragments belonging to the object are white, having an alpha value higher than zero. With this value, it is impossible to see through the fragments or the object, providing the perception of the fragment's location as the surface of the object. With varying alpha values, we could observe some fragments located behind the object which might give an inside look.
Volumevis can only support black and white images currently, which is suitable for CT and MRI datasets. The latest update includes bug fixes for slice loading of textures which are not of power-of-two dimensions, and movie recording, cropping, and file saving for slices. Also, various feature improvements have been made. Overall, Volumevis serves as a great tool for displaying 3D pixel-based datasets.
Version 0.6.2: N/A