Apple Shake 4 - Manual (Page 453)

Chapter 16 Compositing With Layer Nodes 453
The Layer Nodes
This section provides a detailed description of each of the layer nodes.
AddMix
The AddMix node is similar to the Over node, except that you have control over curves
to help blend the edges together. For more information on the Over node, see “
Over ”
on page 466.
ISub A-B r-r2
ISubA Find the difference
between elements. absolute(A-B) fabs(r-r2)
KeyMix Mix two images
through a third mask. A*(1-M*C)+ (B*M*C) M represents the
percentage mix.
Max Combine masks. If (A > B) then A,
else B r>r2?r:r2 or
max(r,r2)
Min If (A < B) then A,
else B rmin(r,r2)
Mix Cross-fade. A*(1-Mix)+(B*Mix) r*(1-mix)+r2*mix
Outside Mask elements. A*(1-Ba) r*(1-a2)
Over Primary compositor A + (B*(1-Aa)) r+(1-a)*r2
Screen Add reflections and
light elements without
losing highlight detail. 1-(1-A)*(1-B) 1-(1-r)*(1-r2)
Under A reverse of Over B + (A*(1-Ba)) r2+r*(1-a2)
Xor Find areas that are
mutually exclusive. A*(1-Ba) + B*(1-Aa) r*(1-a2) + r2*(1-a)
ZCompose Create Z-depth
composite. If(Aa == 1) then
If (Az == Bz) then
((A + (B*(1-Aa))) +
B + (A*(1-Ba)) ) / 2
else
If(Az < Bz) then A
else B
else A + (B*(1-Aa))
If foreground alpha
does not equal 1, an
Over is performed.
Otherwise, if the Z
values are not equal,
the lower Z is taken. If
the Z values are the
same, the result is a 50
percent mix of an Over
and an Under.
Layer Node Common Uses Math LayerX Syntax