Contour shading lets you render vector-based contour lines. Contours are similar to the ink component of the Ink 'n Paint material.
Model rendered without contours
You add contour rendering by assigning one of the contour shaders to the Contour component of a material. This component is found on the mental ray Connection rollout of most materials and on the mental ray material's Advanced Shaders rollout. Then when you render, use the Contours group controls on the Camera Effects Rollout (mental ray Renderer) to enable contours.
On the Camera Effects rollout, additional shaders can modify the contours, or control how they are rendered. For example, to render only the contours, but not the shaded model, assign a Contour Only shader to the Contour Output component.
To add contours to a mental ray rendering:
Preferences. Go to the mental ray panel, and turn on Enable Mental Ray Extensions.
(Render Setup).
If mental ray is not already the active renderer, go to the Common panel, and on the Assign Renderer rollout, click the “...” (Choose Renderer) button for the Production renderer. The Choose Renderer dialog opens. Highlight “mental ray Renderer” in the list, and then click OK.
Open the Material Editor. For the materials of objects you want to render with contours, use the mental ray Connection rollout to assign a shader to the Contour component.
Another technique would be to use the mental ray material, and assign shaders to both the Surface and Contour components.
To simply add contour lines to a rendering, leave the shaders in the Camera Effects rollout set to their defaults. For other options, see Camera Effects Rollout (mental ray Renderer).
The Combi contour shader is a combination of the Depth Fade, Layer Thinner, and Width from Light shaders.
The Curvature contour shader traces a line whose thickness depends on the angle between normals of adjacent faces.
The Depth Fade contour shader changes the line width and color based on Z depth, in world units.
The Factor Color shader uses the color of the material as rendered by mental ray, as opposed to the diffuse color.
The Layer Thinner bases the contour lines’ thickness on the trace depth as determined by the Contour Contrast Function Levels shader.
The Simple contour shader draws all lines the same width.
The Width from Color shader bases the thickness of contours on the brightness of the color of your materials. The brighter the color, the thinner the contour.
The thickness of contours generated by the Width from Light shader are based on the direction of a light you can specifiy in your scene.
The Width from Light Dir shader modifies the thickness of contours based on the direction specified by a "virtual light vector" as defined in the shader. The virtual light is used only to calculate the contours; it does not affect the scene in any other way.
