This page gives some basic details about the Raw Shadow render element and explains how it is used.
The Raw Shadow Render Element stores information about cast shadows calculated from the lighting in the scene. It is a "reverse" image in the sense that white areas indicate shadows while black areas indicate no shadow.
UI Path: ||Render Setup window|| > Render Elements tab > Add button > VRayRawShadow
This render element is enabled through the Render Elements tab of the Render Setup window in 3ds Max and displays its parameters in a rollout at the bottom of the window:
vrayVFB – When enabled, the render element appears in the V-Ray Virtual Frame Buffer.
deep output – Specifies whether to include this render element in deep images.
color mapping – Applies the color mapping options specified in the color mapping rollout of the V-Ray tab in the Render Setup window to this render element. This option is enabled by default.
multiplier – Sets the overall intensity of the render element, where 1.0 is the standard multiplier.
The Raw Shadows Render Element is useful for changing the appearance of shadowed areas after rending in a compositing or image editing application. Below is an example of its use. In the example below, the Raw Shadows were added (plus) with the VRayRawLighting Render Element.
Raw Shadow Render Element
Original Beauty Composite
Shadows lightened by adding the Raw Shadow Render Element
Underlying Compositing Equation
VRayRawShadow x VRayDiffuseFilter = VRayShadows
Shadows can be both added and subtracted at a composite level without rerendering using the Shadow Render Elements.
Shadows can be color corrected using the Shadow Render Elements.