The present disclosure relates to the technical field of video coding. Implementations herein provide methods for fast 3D video coding for high efficiency video coding HEVC. The methods speed up the view synthesis process during the rate distortion optimization for depth coding based on texture flatness. The implementations include extracting coding information from textures, analyzing luminance regularity among pixels from flat texture regions based on statistical method, judging the flat texture regions using the luminance regularity for depth maps and terminating the flat texture block's view synthesis process when processing rate distortion optimization. Compared to original pixel-by-pixel rendering methods, the implementations reduce coding time without causing significant performance loss.