The falling water is being rebuilt, and most of the rebuild is switched off while it is judged. It starts from measurement: the motion of the water was measured from public-domain footage of Yosemite Falls. On the lower fall the water follows free fall to about 30 m/s at 60 m. On the upper fall the packets of water level off at 15 to 22 m/s. Packets come every 9 to 10 m and are 1 to 3 m long.
Built so far and off by default: water that slides on rock lies on it as a thin, dark, glassy film, white only in threads where it breaks. Free-falling water leaves the lip on an arc as a braided column in layered clumps, and ends in a ragged tongue instead of a square edge. The wall and slab beside the water darken as wet rock, with a larger cloud of mist at the foot.
None of it is good enough to switch on yet. In test frames the new sheet is darker and glassy but looks like plastic, with torn, hard-edged flaps. One pass made the slab water almost disappear up close, and the larger mist cloud can show as separate puffs. So the default build keeps the older sheet.
Two pieces did go into the default build on November 14: the white water is a duller white against the granite, and its packets ride down at the measured speeds, where they were capped at 14 m/s.
