This page provides information on the Bump Normals Render Element which creates a normal-style image from the camera view from bumps and normals in the scene.
V-Ray Bump Normals is a render element that stores the camera view as a normal map. The normals are generated using screen space (the Screen coordinate system in Maya) which uses the XYZ orientation of the camera view. With Screen space, the X axis runs left-right across the view, Y runs up-down, and Z points out of the screen. Bump maps are also represented in this render element. For a diagram that illustrates how normal-style colors are generated, see the Normals (vrayRE_Normals) page.
This render element is similar to the Normals (vrayRE_Normals) Render Element that does not include bump maps.
The Bump Normal Render Element is useful for adjusting lighting that comes from a particular direction. For example, faces of objects pointing toward the camera will be predominantly blue in vrayRE_BumpNormals, so the lighting on such objects can be adjusted by using the blue channel in compositing software.
UI Path: ||Render Settings window|| > Render Elements tab > BumpNormals
The parameters for this render element appear in the Attribute Editor under Extra V-Ray Attributes.
Enabled – When checked, the render element appears in the V-Ray Virtual Frame Buffer.
Deep output – Specifies whether to include this render element in deep images.
Filename suffix – The text added to the end of the rendered file, when saved as a separate file (e.g. myrender.bumpnormals.vrimg).
Common Uses - Relighting
The Bump Normal Render Element is useful for changing the appearance of lighting in a scene in a composite without the need for re-rendering. In the example below, a lighting workflow is used at a composite level to change the lighting in the scene. Note that it does not create any extra shadowing. While the Bump Normal Render Element provides information about how lights will affect each surface, the Point Position element passes the spacial location of each pixel. When used together, it allows lights added in compositing to react to the pixels as if they were on the surface of the model.
Bump Normals Render Element
The World Positions pass
Original Beauty Composite
The resulting relit composite
(2 point lights of varying intensities and colors were used along with a directional light)