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Volume Graphics (lecture 6 : Transfer Fucntion) slides knowledgement : G. Kindlmann. Bong-Soo Sohn School of Computer Science and Engineering Chung-Ang University. Transfer Function. Transfer functions make volume data visible by mapping data values to optical properties. volume data.
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Volume Graphics(lecture 6 : Transfer Fucntion)slides knowledgement : G. Kindlmann Bong-Soo Sohn School of Computer Science and Engineering Chung-Ang University
Transfer Function Transfer functions make volume data visible by mapping data values to optical properties volume data
Optical Properties • Anything that can be composited with a standard graphics operator (“over”) • Opacity: “opacity functions” • Most important • Color • Can help distinguish features • Emittance • Why don’t we use this more often? • Phong parameters (ka, kd, ks) • Index of refraction
Volume rendering with different transfer function • Setting transfer function is difficult, unintuitive, and slow
Goal • Make good renderings easier to come by • Make space of TFs less confusing • Remove excess “flexibility” • Provide one or more of: • Information • Guidance • Semi-automation • Automation
Interaction Tools • Data Probe • Clipping plane • Classification Widget • Triangle • rectangle