Abstract: The goal of the presented study is to increase the effectiveness of recreating realistic shadows of dynamic 3D movie characters at the stage of digital post-processing of film and video material due to mathematically justified temporary replacement of high-poly three-dimensional surface modeling by low-polygonal without compromising the quality of the final product in the cinematographic industry. The object of this scientific research is the filmed and mounted film and video material and individual graphic images of film frames. The subject of the article are models, methods and algorithms for digital processing of video material. The methods of three-dimensional surface modeling by various polygons, program algorithms for geometric calculations of invisible lines and projections of 3D objects onto a three-dimensional surface are studied. New effective methods and software algorithms for reducing the dimensionality of the polygonal 3D model have been developed, which are justified mathematically and have made it possible to significantly reduce the amount of computer calculations of dynamic shadows without degrading the quality of the video material. An example of the practical implementation of new models and methods for recreating shadows in cinematography is given.