Modeling of realistic clouds always was one of the most important problems in creating any virtual scenes outside. It has always been an extremely valuable feature for great variety of applications: from flight simulators or meteorological software to computer games especially with an open world. In this work the algorithm of rendering flat clouds in real-time is presented. The hemispherical grid was designed to fill natural placement of clouds. Tools for high-quality visualization of stratocumulus clouds were created. The model of light scattering through clouds is described. This approach allows rendering realistic clouds evolving through time at high frame rates. © 2015 The Authors.