TY CONF TI Synthesis methods for realistic images of three-dimensional scenes containing media with a refractive index gradient KW ray tracing KW gradient medium KW Runge-Kutta method KW rendering KW photon maps JO International Conference "Computing for Physics and Technology - CPT2020" AU Zhdanov, D.D. AU Potemin, I.S. AU Zhdanov, A.D. AU Galaktionov, V.A. AU Garbul, A.A. PY 2024 PB ANO "Scientific and Research Center for Information in Physics and Technique"