Creating Curves from Surfaces

The Generate curves from surfaces tool can be used for creating a set of NURBS curves from a surface with a specified accuracy. The curves can then be used for various purposes.

In this tutorial we will create a vase which consists of numerous 'fibers'. The fibers are texture mapped NURBS curves.

1. Use the 'Rotate' mesh construction tool to create a vase.

Create a NURBS vase

2. Select the vase and apply the 'Curve' construction tool from the NURBS tool tab.  Use the control bar to specify suitable options.

The 'Curv' extraction tool activated

Use the 'U Curves' and 'V Curves' options to specify whether curves should be evaluated in the 'u', 'v', or both the directions of the mesh.

The 'Curves' field specifies the curve extraction density. Note: this option doesn't define the total number of curves but the density. The value 1 gives the minimum number of curves. The higher the value, the higher the curve count.

The 'Points' field specifies the number of control points per curve. Again, this is not the 'absolute' point count but specifies the density for point insertion. The higher the value, the more points will be created to the curves.

Check both 'U Curves' and 'V Curves' options. Set 'Curves' to 8 and 'Points' to 1. Then accept the tool.

The vase converted to a set of NURBS curves

3. Select the root object and drag & drop the 'particlefur' material into the view window. You can also use another material to define a desired color and other properties for the vase.

A basket created from texture mapped NURBS curves

4. Select all curves (select the first curve, scroll down, press and hold the Ctrl key and select the last one), open the property window and go to the Gen tab. Uncheck the 'Invisible in photo realistic rendering' option. Render the view.

If you need to modify the number of curves, select the 'Curve Manager' object from the select window and use the property window to specify a new curve count.

Property window of the curve manager object

The 'Displacement' attribute displaces the curves from the surface.

The 'Channel' selector allows you to use any material to modify displacement values. To use this feature, map a material to the curve manager and specify a channel, such as color, which controls the density. The given channel is evaluated over the surface and values are used to scale the displacement defined by the 'Displacement' option.

Non-uniform displacement defined by the 'Spotty' material

Tutorial project: 'tutorprojects\modeling\nurbs\surfacetocurves\vase'