User Manual

The Scene Input
The nodes offer a Scene input, which can either be a 3D camera or a 3D scene containing a
camera. While the camera is vital for the Z to World node, Volume Mask and Volume Fog can
generate their output without any camera attached or with the camera position set to 0/0/0.
However, connecting a camera that lines up with the original camera the WPP has been
rendered from, or setting the camera’s position manually, dramatically improves the accuracy
and look of the resulting Fog or mask.
The “Invisible Sphere”
The example scene shown so far has an empty background, meaning there is nothing in the
scene apart from the ground plane and the cubes.
If applying fog to a scene like that, which is larger than the ground plane, the result will look
similar to the “w/o Sphere” example shown below because, with no WPP information outside
the ground plane, the resulting value is 0/0/0, and the fog fills that area as well.
To get around that, you can add an invisible bounding sphere to your scene to create “dummy”
WPP values to help the Fog node to create the correct volume as shown in the “with Sphere”
example below.
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