What is meant by U curves and V curves .? U cross sections and V cross sections, I often come across these words while using loft and skin.CAn anyone help me .

What is U and V here ? ops: feeling confusive

In a simple nurbs patch (picture a square), you have two parametric directions that define locations on the patch: horizontal and vertical. You can think of that patch as a loft of two curves (straight lines). The horizontal is the U line and the vertical is the V. In a more complicated lofted surface, instead of having one line define the patch direction, you have multiple but the principle is the same. Each U curve defines the surface in one direction and each V curve defines it in the other.

When lofting (more correctly U-Lofting, or skinning in Houdini parlance), the direction of the loft (what you might think of as the spine of the loft), is often assumed as the “U” line of the loft or skin. The cross sections (what you might think of as the ribs of the loft) are the “V” lines.

Thanks , Excellent explanation.