Thicken

transform lines to tubes or points to spheres

Purpose

The Thicken module can be used to expand lines into tubes or points into spheres. The radius of the resulting tube/sphere can be set to a fixed value or be dependent of a given scalar value.

Ports

The first input port grid_in is required and expects lines or points which the module will expand to tubes or spheres. The module automatically detects whether lines or spheres are provided. The second input port data_in is optional and takes a data field that can be used to calculate the radii of these tubes/spheres.

Parameters

name	description	type
radius	radius or radius scale factor of tube/sphere	Float
sphere_scale	extra scale factor for spheres	Float
map_mode	mapping of data to tube diameter (DoNothing, Fixed, Radius, InvRadius, Surface, InvSurface, Volume, InvVolume)	Int
range	allowed radius range	Vector
start_style	cap style for initial tube segments (Open, Flat, Round, Arrow)	Int
connection_style	cap style for tube segment connections (Open, Flat, Round, Arrow)	Int
end_style	cap style for final tube segments (Open, Flat, Round, Arrow)	Int
correct_depth	correct per-fragment depth for impostor spheres (slow)	Int

There are different modes for setting the radius of the resulting geometric bodies which can be selected with map_mode in the parameter window. Additionally, the radius and sphere scale parameters can be altered, to fine-tune the resulting radius and a range can be given for clipping the values of the radii.

Map modes:

DoNothing: Does not change the geometry. However, if data_in is not empty, the mapped data is added to grid_in and returned through the data_out port.
Fixed: Sets the radius to radius. If the input grid is a spheres object, it additionally multiplies the value sphere scale to the radius. We will refer to this value as Fixed-scale in the following.
Radius or InvRadius: Maps the data values (or its reciprocal, respectively) provided through data_in (multiplied with Fixed-scale) to the radii of each data point/line. If the data is three-dimensional, the L2-norm is calculated.
Surface or InvSurface: Like Radius or InvRadius, respectively, but before Fixed-Scale is multiplied to the radius, the square root of the values in data_inis calculated.
Volume or InvVolume: Like Surface or InvSurface, respectively, but instead of the square root, the cube root is calculated.

Usage Examples

Fig.1. Example workflow using Thicken (left) and step-by-step results (right). On the top-right, a scalar data set is shown as points which can only be seen by zooming in considerably. In the center, the same data set is shown as spheres. At the bottom, the vector field has been added, after expanding its lines into tubes.

In this example, the scalar data field of a data set is first transformed into points via ToPoints (see top-right image) and then thickened into spheres (see image in the center of the right image). The radii of the spheres depend on the scalar data field. Note: To avoid rendering errors, it is important to pass the output to the ToTriangles module whose transform spheres parameter has been enabled.

Moreover, three-dimensional input data is transformed into a vector field through the VectorField module and the resulting lines are expanded into tubes (see bottom of the right image).