Volume Exploration and Presentation Tool. Drishti stands for vision or insight in Sanskrit, an Indian language. This tool provides facility to animate transfer functions, animate volumetric time series, animate sub-volumes, all this and much more.

Drishti Features:
Source Code
1. C++ code + OpenGL + wxWindows for user interface
2. Uses GPU for rendering (using glsl shader language)
3. Portable (in principle)

Data Sets:
1. Large volumes (10243 regularly explored)
2. Two same sized volumes together
3. Volumetric time-series
4. Loads image stacks - including DICOM images

Classification / Segmentation:
1. Two-dimensional transfer functions
2. Transfer function sets for various purposes
3. Region growing using user provided seeds

Animation:
1. Transfer function animation
2. Sub volume animation
3. Overlapping subvolume possible
4. Each subvolume can have its own transfer function set
5. Time-series animation
6. Camera path
7. Clip plane animation
8. Streamline animation

Vector Data Sets:
* Interactive Streamline generation and rendering

Rendering and Shading:
1. User defined glsl-shader scripts for rendering and shadowing
2. User controlled quality of rendering to suit GPU capability
3. User controlled lighting - control lighting with transfer functions
4. Self shadowing and Subsurface Scattering for volumetric objects.
5. Shadows using FrameBufferObject when ever possible
6. Reverts to RenderToTexture if not.
7. Works on Mac and Linux
8. Back Lighting
9. Different transfer functions can be blended from back to front
10. Emissive Color

Tools:
1. Inbuilt help
2. Extract data from netCDF files
3. Graphical interface for downscaling volumes
4. Cropping and scaling for image stacks
5. Cropping and scaling for RAW volumes
6. Place markers directly on volume data
7. Volume masks
8. Volume estimation
9. Enclosing surfaces
10. Tensor visualization with superellipsoids
11. Network (Graph) visualization
12. Distance measurements
13. Legend display
14. Caption Editor
15. Slices
16. Clip planes
17. Screen Lens
18. Stereo viewing
19. Polhemus tracker enabled for VR setup
20. Preset camera positions
21. Display of actual voxel values
22. User defined triangular mesh
23. vSaving Movies
24. VizNotes facility : Provides a journal like facility which can store images along with text in an xml or html file.

The license of this software is Freeware, you can free download and free use this calculator software.