Rework and optimize computation of roughness crosscorrelation
- Now intermediate interfaces explicitly participate in computation of crosscorrelaton terms:
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--------- i
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--------- j
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--------- k
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spectrum_i_k = spectrum_i_j * spectrum_j_k / spectrum_j
- Computation of cross-interface scattering on roughness is optimized.
Now it is several times faster due to caching.
Edited by Mikhail Svechnikov