Table 1 Shaders used for visualization

Vertex shader

Bounding box

Model and view matrix applied to lines without lighting effect

Bundle

Model and view matrix applied to tract 3D data with Phong lighting algorithm

Coordinate system

Model and view applied to volumetrical arrows without lighting effect

Cylinder

Pass through shader for tract data

Mesh

Model and view matrix applied to mesh 3D data with Phong lighting algorithm and opacity

Volume-slice

Model and view matrix applied to vertex from bounding box collided with plane

Geometry shader

Cylinder

Model and view matrix applied to a line-to-cylinder algorithm

Quaternion

Functions describing quaternion mathematics

Fragment shader

Standard fragment shader

Pass through shader for color data

MRI slide

Evaluation of pixel color for 3D texture (MRI data)

MRI volume

Evaluation of pixel color for 3D texture (MRI data) and Phong lighting algorithm using gradient estimation as normal