The Diffuse Filter Render Element shows the colors and textures used in materials, flatly applied to objects with no lighting information. The colors are the actual colors set in the material definition, and each texture appears as it does in the texture (file) itself. There are no highlights or shadows, and any background image is not included.

Other render elements that include colors from materials are said to include the diffuse contribution or the diffuse component  of the rendered scene. The Diffuse Render Element contributes this diffuse component; any render element that includes this diffuse component is a combination of V-Ray Diffuse and other render element(s).

This render element is, by itself, useful for making overall adjustments and enhancements to colors and textures during compositing.

The Diffuse Render Element is useful for changing the appearance of many passes when it is combined with Raw render passes (like V-Ray Raw GI ,V-Ray Raw Light , etc.). In the example below, the Diffuse is multiplied by the Raw GI Render Element to provide the GI element. In this way, color correction can be performed upon the raw pass without the actual diffuse colors being changed, making it possible to tint a pass in a realistic way without re-rendering.

The Diffuse Filter is a very useful render element due to the number of raw passes with which it can be combined, giving the ability to manipulate many areas of the render at the composite level. The Diffuse Filter pass can also be color-corrected on its own, as shown in the example below. In this case, a Multimatte Channels Render Element was used in conjunction with the Diffuse Filter render element to isolate the dangling light and change its color from white to blue without also tinting its lighting or shadowing in any way.

Diffuse Filter Render Element

Diffuse Filter Render Element
with color correction on dangling light

Beauty Render Element

Resulting composite with Diffuse Filter Render Element
with color correction on dangling light

Compositing Formula

V-Ray Diffuse Filter x V-Ray Raw GI = V-Ray GI

V-Ray Diffuse Filter x V-Ray Raw Light = V-Ray Lighting