ZCompose

Function
This composes the input image over the background image using the Z values of both images to determine which image's pixel is placed on top.

Z values are depth measurements from the camera to each object. A pre-multiplied image is assumed since Z values normally are produced by a render. With a ZCompose, one of the images' pixels is either on top or not. This is sometimes a problem if you have subpixel objects. You might have ten dust particles in a single pixel, but if only one of them is in front of the corresponding object in the other image, then the pixel containing all ten particles will be placed in front of that object. The problem is that the pixel doesn't contain the subpixel objects, just a representative color. For similar reasons, object edges can also be a problem.

For a tutorial on Z-compositing, try the Blimp Tutorial.

Parameters
Type
Defaults
Function
clipMode
int
1
Toggles between foreground (0) and background resolution (1)


Synopsis

image ZCompose( 
  image Foreground, 
  image Background, 
  int clipMode 
);


Script

image = ZCompose( 
  Foreground, 
  Background, 
  clipMode 
);


Command Line

shake -zcompose image clipMode

See Also
LayerX