| 9 |
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* in the surface plane pointed to the right as seen from the front. |
| 10 |
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* This means the Y-axis is "up" and the Z-axis is the surface normal. |
| 11 |
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* |
| 12 |
+ |
* Note that we reverse the identification of "front" and "back" from |
| 13 |
+ |
* the conventions used in WINDOW 6. "Front" in our library points |
| 14 |
+ |
* in the +Z direction, towards the interior of the space rather |
| 15 |
+ |
* than the exterior. |
| 16 |
+ |
* |
| 17 |
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* BSDF vectors always oriented away from surface, even when "incident." |
| 18 |
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* |
| 19 |
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* Created by Greg Ward on 1/10/11. |