Interactive Design of Complex Time- Dependent

rendering algorithms. design must complement such timedependent phenomena as the motion of performers, the changing focus of attention, and the shifting mood of the plot. In addition, the design must remain precisely synchronized with the music. The most difficult and time-consuming part of the lighting design process is determining changes in lighting intensityover time, or dimming. The lighting designer must determine how lights of different intensities combine at any moment, what temporal changes are necessary to achieve the desired effect, and at what rate the intensity changes should occur. In this context, dimming connotes the complete temporal specification of lights and therefore includes increasing as well as decreasing the intensity. The complexity and subtleties of the tasklimit designers to very rough decisions about changes in lighting intensity prior to constructing the final sets and placing and focusing the lighting instruments. Synchronizing a large number of lighting instruments is far too difficult to visualize with conventional media. On the other hand, the simulations shown in the “Results” section depict ;i scene at several points during a lighting animation. They demonstrate the dramatic effects possible by varying lighting intensities.