Houdini 20.5 Nodes APEX nodes

rig::RBFInterpolation

Performs radial basis function (RBF) interpolation.

On this page
Since 20.0

Given a set of example values, this node computes weights for a given target value (in the same space of the examples) via radial basis function (RBF) interpolation.

Inputs

target: FloatArray

The input value to compute the weights for, given how it resides among the example values.

examples: FloatArray

Example target values concatenated into a single float array for performing interpolation. The length of examples must be a multiple of target's length.

clamp: Bool

If set to True, target's values are first clamped within the range of the example target values so that the weights produce an interpolated result that never falls outside the range of the example values.

hyperplane: Bool

If set to True, a best fit method is used to extrapolate the data outside of the example values.

kernel: Int

The kernel function used for the radial basis function interpolant. Different kernel functions result in varying fits.

kernel

Interpolant

0

Thin Plate

1

Biharmonic

2

Cauchy

3

Gaussian

4

Multiquadric

5

Inverse Multiquadric

6

Exponential Bump

exponent: Float

The exponent used for the Thin Plate kernel function (ie. when kernel is set to 0). Larger values give smoother results.

falloff: Float

The radius distance of influence from the example target values. Larger values give smoother results.

damping: Float

The damping used for the interpolation solver. This is normally not needed unless the solver is failing. In that case, start with a very small damping value like 0.00001. Then use successively larger values like 0.0001, 0.001, 0.01, etc. until the solver succeeds. This can cause interpolated values at the examples to be slightly off.

robustsolver: Bool

If set to True, uses the more robust solver at the expense of speed.

reload: Bool

If set to False, performs internal caching according to the sizes of the target and example inputs, and does not recompute if only the values within target and example change. To disable caching, set this to True.

Outputs

weights: FloatArray

The interpolated weights for target among the examples. These weights should be used for a linear combination (or weighted average) of values for performing scattered interpolation. The values could be blendshape positions (eg. for pose space deformation) or any other set of values corresponding to the examples.

APEX nodes