SetBGColor

Function
This sets selected channels to the selected color outside of the Domain of Definition (DOD). For example, if you create an Image - RGrad, you will see the green box around it in the Viewer. This is the DOD, meaning everything outside of this is understood to be black, and therefore does not have to be computed. By attaching a SetBGColor to the node, and changing the color, everything outside of the DOD changes.

This function is often used for adjusting keys, as the keyer may be pulling a bluescreen, and therefore will assign the area outside of the DOD, which is black, as an opaque foreground. If the element gets scaled down and composited, you would not see the background. The solution is to insert a SetBGColor before the keyed element is placed in the composite, i.e., ChromaKey -> SetBGColor -> Scale -> Over.

See Overview - the DOD for more information.

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