Houdini 20.5 Nodes Geometry nodes

Measure Thickness geometry node

Measures point-wise thickness.

This node measures the thickness of the input object at its point locations. Thickness can be estimated using the Ray Length method or the Max Fitting Sphere method. Both methods generate thickness estimate samples at each point by using ray computations. The results are filtered locally first, then they are filtered globally among neighboring points to achieve robust estimates.

This node assumes a clean input geometry. If your geometry has self intersections or unclosed surfaces, it is recommended that you fix such issues before passing the geometry to this node.

Parameters

Group

Group of points at which we estimate the thickness.

Thickness Attribute

Output attribute name.

Max Thickness

Maximum thickness cap in world space unit. Set this to a higher value when your object is larger in scale.

Scan Settings

The detail settings about sample generation and filtering per point.

Use Input Normal

When this is turned on, the thickness computation will be performed using the user-specified input normals. It is recommended that you leave this turned off.

Consolidate Normal

When this is turned on, the node internally performs snapping of near points to compute normals according to the snap distance below. Turning on this option does not change the number of points.

Snap Distance

The snap distance used when the Consolidate Normal option is turned on.

Ray Offset

The offset of ray intersection test in world space units. A very small positive value is recommended, but you may need to adjust this depending on the input scale.

Extra Samples

Number of extra random samples generated in addition to a sample generated using the inward normal per point.

Stratify Samples

When this is turned on, the extra random samples are generated more uniformly over the valid range.

Sample Filter

How the samples are filtered per point.

Average

Uses the average of all thickness estimates.

Max

Picks the largest thickness estimate. This is recommended for the max fitting sphere method.

Min

Picks the smallest thickness estimate.

Median

Picks the middle of the thickness estimates.

Robust

Uses the average of all thickness estimates that pass a robust outlier removal filter. This is recommended for the ray length method.

Random Seed

Random number seed used to generate rays in random directions.

Scan Cone Angle

Maximum angle in degrees away from the center that any sample will be.

Measurement Method

Thickness sample measurement method.

Ray Length

Generate samples by measuring the length of a ray cast from the point to the geometry.

Max Fitting Sphere

Generate samples by measuring the largest fitting sphere centered on a ray cast from the point inscribed inside of the input geometry.

Max Fitting Sphere Settings

Detail settings of the max fitting sphere method.

Refinement Iterations

The number of iterations for the binary search algorithm used to determine the largest fitting sphere along a ray.

Edge Sharpness Tolerance

Tolerance level to the sharpness of geometry in angle. Increasing this gives larger thickness estimates at sharp corners.

Min Thickness

Minimum thickness returned by the algorithm.

Use SDF

When this is turned on, the method uses a SDF based on VDB to compute maximum fitting spheres internally for acceleration. This is useful if the geometry is highly detailed.

SDF Voxel Size

The size (length of a side) of the cubic voxels for SDF. Adjust this based on the global and local scale of input geometry.

Global Filter Settings

How the thickness estimates at all points are filtered among neighbors.

Median of Neighbors

When this is turned on, the thickness estimates are filtered across neighboring vertices using a median filter.

Use Blur Filter

Whether to blur the output thickness estimates using Laplacian filtering.

Blur Iterations

How many times a blur filter is applied.

Geometry nodes