One aspect of the present invention relates to a solar power unit comprising a frame, configured to be integrated into a building structure, for supporting a solar panel, the solar panel for generating a power signal, and a front cover for securing the solar panel to the frame. The real-time method involves receiving animation data, the animation data used to animate a computer generated character. The heater unit is switched on when the sensor temperature is equal to or lower than a first threshold, and is switched off when the sensor temperature is equal to or higher than a second threshold. The method further includes up-sampling the low-pass-filtered sequence of samples by a factor M with a polyphase filter bank having a windowed sinc characteristic to the up-sampled sequence of samples, and down-sampling the polyphase-filtered sequence of samples.