Dali Renderer can render 3D spline curves directly without converting them to triangular geometry. They can be sourced from 3DS MAX spline objects or third party plugins (currently Ornatrix).
Each curve is stored as a real cubic spline during rendering, no segmentation is performed. For a curve, you can specify the distribution of its diameter along the curve using another spline. In addition to the diameter, an aspect can be set - the "ellipticity" of the section.
The curves are textured with two sets of texture coordinates.
The first UVW0 set contains the coordinates on the surface of the spline itself. With their help, you can apply a texture to the spline.
The second UVW1 set contains the UV data that the spline source exports. This set can be used to set the color of individual hairs. The W coordinate changes monotonically along the curve.
Each spline from a spline object can have its own material. The shape of the spline can be animated within the frame for Motion Blur.
The Dali Renderer tab sets the settings for rendering an object with splines.
Subdivide strands
Very long splines, such as long hair, must be split into several other splines. This does not affect the quality of the image, and this is not a translation of a spline into a triangular mesh (Dali Renderer does not do so). This is purely for rendering speed. If splines are too long, then the efficiency of the optimizing structure for rendering will be low.
Min Levels - the minimum number of iterations for splitting. 0 - no splits; 1 - two new splines; 2 - four new splines; 3 - eight new splines, etc.
Max Levels - the maximum number of iterations for splitting.
Max length - maximum spline length without splits.
Default thickness
The base thickness (diameter) of the spline relative to a human hair.
Radius
Relative change in spline thickness along the central curve at fixed points: at the beginning of the curve, at 1/3 of the length, at 2/3 of the length, and at the end.
Aspect
"Ellipticity" of the spline section.
Map
Rendering will prepare additional data for further texturing. This takes some time on every hit of ray and if advanced texturing is not required, it can be turned off.
Smooth
Sometimes the original curve is specified as a polyline. This option allows you to convert it into a smooth spline of the third order.
Render precision
Increases rendering accuracy. The option is needed if the spline is very close to the camera.
