SetBGColor

Function
The SetBGColor function sets selected channels to the selected color outside of the Domain of Definition (DOD). For example, if you create an Image–RGrad, the green DOD box appears around the RGrad image in the Viewer. Everything outside of the DOD is understood to be black, and therefore does not have to be computed. To change the area outside of the DOD, attach a SetBGColor to the node and change the color.

This function is often used for adjusting keys, as the keyer may be pulling a blue screen, and therefore assigns the area outside of the DOD, which is black, as an opaque foreground. If the element is scaled down and composited, you do not see the background. To correct this, insert a SetBGColor before the keyed element is placed in the composite, for example, ChromaKey > SetBGColor > Scale > Over.

 

Parameters
Type
Defaults
Function
mask
string
"rgbaz"
The channels being reset
red, green, blue, alpha, depth
float
0,0,0,0,0 The values of the associated channel


Synopsis

image Set( 
  image In,
  const char * mask,
  float red,
  float green,
  float blue,
  float alpha,
  float depth
);


Script

image = Set( 
  In,
  "mask",
  red,
  green,
  blue,
  alpha,
  depth,
);


Command Line

shake -set channels value