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Zodiak User Manual 45
Transitions
Current and Next Stack
Zodiak uses a current and next stack approach for transitions that involve
multiple elements. The current stack is the current M/E output including
any keys that are on. The next stack is defined by the current stack and
whatever next transition elements have been selected. Look ahead preview
always displays the next stack. Next transition elements affecting stacks are
Keys 1 - 4, background, and key priority.
Zodiak transitions always occur from the current stack to the next stack.
For example, if the current stack has Key 1 over Background A, and the next
stack specifies Key 2 over Background B, a mix transition will occur
between the composites (Key 1 over A to Key 2 over B). This is different
from mixing Key 1 off, Key 2 on, and mixing between A and B at the same
time, which would cause the keys to go transparent over their background
during the transition.
On the Zodiak system, opacity is retained throughout the transition, so
midway through this example Key 1 remains fully keyed over Background
A, and Key 2 is fully keyed over Background B. The transition occurs
between these two fully keyed composites.
Key Priority and Transitions
The four keyers on a Zodiak M/E can be assigned priorities. This deter-
mines the layering of the keys. The highest priority key appears on top,
while keyers with lower priority may be partially or fully hidden behind
those with higher key priorities. The backgrounds always have the lowest
priority. Changes in key priority can be included as a part of a transition.
Like any other transition, the current stack will transition to the key pri-
ority of the next stack. For example, suppose the current stack has Keys 1,
2, and 3 in that key priority order over Background A, and the next stack
specifies key priority order 3, 2, 1. A mix transition will occur between the
1, 2, 3 composite order to the 3, 2, 1 composite order. All three keys will
remain fully keyed over the background, and will mix to their new key pri-
ority order.