Realistic Image Synthesis Using Photon Mapping
A practical guide to photon mapping, this book provides both the theory and the insight necessary to implement photon mapping and simulate all types of direct and indirect illumination efficiently.
TABLE OF CONTENTS Realistic Image Synthesis Using Photon Mapping
Appendix C: A Cognac Glass Model
This appendix contains the data used for the cognac glass model which has appeared in several images in this book. It is a good model for simulating caustics.
The data is given as three contour curves. There is a contour for the cognac-air interface, the glass-air interface, and the cognac-glass interface. The three interfaces are necessary to properly account for Fresnel effects. Modeling a volume of cognac inside a glass with a tiny bit of air between the two would not be correct.
The contour curves can be typed into most modeling programs. The cognac glass is then created by rotating this curve around the center axis (radius=0).
The data for the cognac-air interface contour is:
| Height | Radius |
|---|---|
| 6.5 | 3.8 |
| 6.48 | 3.76 |
| 6.45 | 3.75 |
| 6.45 | 0 |
The data for the glass-cognac interface contour is:
| Height | Radius | Height | Radius |
|---|---|---|---|
| 6.50 | 3.80 | cont'd | cont'd |
| 6.05 | 3.79 | 4.33 | 2.70 |
| 5.60 | 3.73 | 3.95 | 1.98 |
| 5.15 | 3.55 | 3.58 | 1.06 |
| 4.70 | 3.20 | 3.20 | 0.00 |
The data for the glass-air interface contour is:
| Height | Radius | Height | Radius | Height | Radius |
|---|---|---|---|---|---|
| 0.90000 | 0.000000 | cont'd | cont'd | cont'd | cont'd |
| 0.77500 | 0.087946 | 1.00000 | 0.500000 | 10.16250 | 2.807188 |
| 0.65000 | 0.167857 | 1.30000 | 0.500000 | 10.55000 | 2.700000 |
| 0.52500 | 0.338839 | 1.60000 | 0.500000 | 10.57250 | 2.695273 |
| 0.40000 | 0.700000 | 1.90000 | 0.500000 | 10.59500 | 2.692188 |
| 0.31250 | 1.178594 | 2.20000 | 0.500000 | 10.61750 | 2.690508 |
| 0.22500 | 1.821250 | 2.27500 | 0.515031 | 10.64000 | 2.690000 |
| 0.13750 | 2.465781 | 2.35000 | 0.556750 | 10.65375 | 2.690469 |
| 0.05000 | 2.950000 | 2.42500 | 0.620094 | 10.66750 | 2.688750 |
| 0.03775 | 2.981703 | 2.50000 | 0.700000 | 10.68125 | 2.680156 |
| 0.02550 | 2.993875 | 2.81250 | 1.149888 | 10.69500 | 2.660000 |
| 0.01325 | 3.009109 | 3.12500 | 1.710119 | 10.69625 | 2.650594 |
| 0.00100 | 3.050000 | 3.43750 | 2.277790 | 10.69750 | 2.633250 |
Copyright A K Peters, Ltd. 2001 under license agreement with Books24x7
