They include filters and brushes, as well as transformation, selection, layer and masking tools. See unsharp masking&colon; local contrast enhancement for details. VEGAS provides sophisticated compositing including green screen, masking, and keyframe animation. Little is known about the effects of masking one's negative emotions. This condition is called error masking or aliasing. The effects of backward masking is weaker than forward masking. This phenomenon is called saccadic masking or saccadic suppression. The process of masking a MAC address is known as MAC spoofing. Some of these flaws had the unfortunate property of masking or explaining other flaws. Encryption is often the most complex approach to solving the data masking problem. Curves can be created and projected on a mesh for use as precise masking. This is caused by odor masking, when one odorant overpowers the sensation of another. Issues include masking (shadowing), clutter (noise), and signal alteration. As of 2011, the industry is conducting research on the causes of odor masking.