Abstract: A video signal combiner includes circuitry for generating a gleam key signal for keying a video image which has been spatially transformed, a plurality of multiplier circuits for simultaneously layering multiple key and video signals in parallel, and circuitry for dynamically maintaining or adjusting Z data priority as the fill video images are spatially transformed. A gleam key is generated in accordance with dynamic planar description data representing the dynamic planar positioning of the gleam within the resultant video image. The gleam key profile or contrast range can be selectively altered prior to its keying of the video image. The multiple key signals can be selectively prioritized relative to one another. The multiplier circuits share common output compensation circuits. Dynamic range for internally generated Z video data is maintained at the maximum range possible using normalized Z data.