1. Volume Rendering A volume representation is an extension of a 2D image to 3D space. A pixel in 2D space become a voxel in 3D space. Voxel

2. Volume Graphics Applications Medical biology (confocal microscopy) geology (seismic measurements) molecular systems (electronic density maps) meteorology (weather prediction simulations) chemistry (new material simulations) industry (non-destructive inspections)

3. Volume Graphics Applications Medical –Professional viewing the MRI data looks at a sequence of 2D images, or "slices", created of the subject. –A group of these slices could be considered as one 3D dataset –MRI images are slices 38 and 54 from 109 slices of size 256x256 taken of a human head

4. Volume Graphics Applications Medical –After Putting all the slices together. –Adding light and shading –Final Image

5. Virtual Lights to Enhance Perception Objects are rendered with shading from "virtual" lights The intensity and color of voxels used to create the final image The voxel intensity are used to estimated normals

6. Rendering Volumes 3D datasets could be converted to polygonal representations of one certain feature (surface). Unfortunately this method allows the user to view only one feature (surface). Volume rendering allows the user to see inside objects so the relationships among multiple features can be examined.

7. Volume Graphics Applications It is quite hard to represent semi-transparent objects such as amorphous clouds, smoke, fire, even jello using polygons. How to mix Polygons with volume ???