This screen recording shows how the molecular modeling program YASARA (www.yasara.org) handles cut-planes. Using one or more cut-planes, objects like surfaces can be cut open to look inside and aid visualization. The animation is part of a YASARA help movie, created by a simple open-source YASARA macro in real-time (60fps) and high resolution using OpenGL in Linux, MacOSX or Windows. This and many more help movies can be downloaded from www.yasara.org/movies. Background created by Sven Geier.