This page provides information on the Curvature texture in V-Ray for Blender.
Overview
Curvature is a texture that will effectively sample the underlying mesh for curves. A region around each shaded point gets sampled with additional rays (similar to Dirt) and all additional normals are averaged to get a "smooth" normal at the original point. This normal is used to compute the color. The color at each shaded point is a grayscale value: darker values are dents (or holes), lighter values are peaks. The parameters should be adjusted by trial and error since they generally depend on the scale used, hence the defaults might not be appropriate at all in some cases.
UI Path: ||V-Ray Node Editor|| > Shader > Add > Textures > V-Ray Curvature
Node Input Sockets
Sample Seed (input socket) – Allows an integer-outputting node to be connected as the Sample Spread.
Properties
Mode – Switch between respective modes.
Legacy – Does not distinguish if the mesh is curving outward (convex) or inward (concave) but instead takes into account only the amount of overall curvature
Convex – Generates a grayscale based on the mesh's outward curve.
Concave – Generates a grayscale based on the mesh's inward curve.
Both – Generates a red-green gradient based on both the mesh's convex and concave. Red corresponds to the mesh's convex and green corresponds to the mesh's concave.
Scale – Adjusts the scale relative to which the curvature is measured.
Threshold – Curvature values below this threshold are ignored and are shown as pure black. This focuses the curvature effect only around the most curved areas of the mesh.
Subdivs – The number of samples V-Ray takes when sampling normals around intersections.
Sample Spread – Controls the radius of the sampled region.
Ignore Bump – When enabled, excludes Bump maps from VRayCurvature computations.
Min Output Color – Specifies the minimum output color value for the most concave area (the dents in the mesh). Default value is 0 - completely black.
Max Output Color – Specifies the maximum output color value for the most convex area (the peaks in the mesh). Default value is 1 - white.
Output Color Gain – Multiplies the output values.
Output Color Lift – Uniformly lightens the output values.
Output Color Gamma – Applies gamma correction to the output values.
Output Color Pivot – Pivots the value to the gamma correction (output values equal to the pivot value are left unchanged).
Output Color Clamp – When enabled, clamps the Output min color and Output max color values in [0,1] range (negative values are output as 0 and values above 1 are being output as 1).
