This page provides information on V-Ray Attributes that can be added to Curves.
The V-Ray Additional Attributes can be added to Curve shape node. This is done from the Attributes > VRay menu in the Attribute Editor with the curve node selected. This makes the curve directly renderable, without intermediate conversion to paint effects or polygons. Internally, the curve is converted to hair.
UI Path: ||Select curve|| > Attribute Editor > Attributes menu > VRay > (select attribute set)
Render – Enables/disables the rendering of the curve.
Material – Specifies the material applied to the curve.
Tessellation step – The curve is internally tessellated into line segments. Smaller values for the tessellation factor will approximate the curvature better, but will cause slower rendering. See the Tessellation Step example below for more information.
Start Width/End Width – Curves in Maya do not have thickness, and these attributes must be used to specify the start/end width of the curve. The start of the curve is shown with U symbol in the Maya viewport.
Lock End Width – When enabled, Start Width controls constant thickness along the curve.
Example: Rendered Curves
In the scene below, an Extra VRay Attribute Renderable is used to create the effect of draped cables.
Curves in Viewport 2.0
Example: Tessellation Step
The Tessellation step parameter affects the number of line segments that are used when approximating the curves. Smaller values will use more line segments to approximate the curve, producing smoother results but slower rendering.
Tessellation step: 1 (default)
Tessellation step: 25
Tessellation step: 50