Houdini 20.0 Nodes Geometry nodes

Volume Bin geometry node

Builds histogram geometry out of voxel values.

This node type is hidden. It is no longer supported.

The Volume Bin SOP scans the given volume and constructs a histogram from its voxel values. There are options on the operator to consider only a subset of the voxels, either through discarding voxels by their value or filtering with an extra Stencil volume. If such a volume is provided, all voxels whose stencil value is less than 0.5 will be discarded.

The exported histogram geometry produced by the Volume Bin SOP also has the following detail attributes.

Note

This node currently only works with standard Houdini volumes. It does not work with VDBs.

Parameters

Volume

The histogram will be built for the input volume of this name.

Stencil

Name of the stencil volume. The histogram will only contain Volume voxels whose stencil value is at least 0.5.

Ignore Value

When enabled, Volume voxels whose value equals Ignore Value will not be counted in the histogram.

Note

The skipped_by_value detail attribute will contain the count of voxels that were skipped due to Ignore Value.

Buckets

Controls the number of buckets in the generated histogram.

Value Range

The method for selecting the histogram range. From Values will automatically set the range from the minimum and maximum of Volume values. When set to Specified, value of the Range parameter controls the histogram range.

Range

The histogram range when Value Range is set to Specified.

Keep All

When this parameter is enabled, all scanned voxels (that are not skipped because of Ignore Value) will be counted in the histogram. If Keep All is disabled, values that fall outside the specified relative range will be skipped.

Keep in Relative Range

Controls the range of values that will be represented in the histogram. This subrange is relative to the main range (as selected by Value Range).

To illustrate, let’s assume that Value Range is set to From Values, and the Volume contains values that fall between 1 and 5, inclusive. Then the natural histogram range in this case is 1-5. If we disable Keep All and set this parameter to [0.1, 0.8], then all values less than 1 + (5 - 1) * 0.1 = 1.4 or greater than 1 + (5 - 1) * 0.8 = 4.2 will be ignored.

As another example, suppose Value Range is set to Specified and Range is [2, 4]. If Keep All is enabled, all voxels whose value is less than 2 will contribute to the first bucket of the histogram. But if Keep All is disabled and the respective relative range is set to [0, 1], then such voxels will simply be discarded.

Note

All represented values will fall within the specified relative range. As such, the histogram range will also be updated to enclose only represented values.

Note

The skipped_above and skipped_below detail attributes will contain counts of voxels that were skipped due to falling outside the specified relative range.

Geometry nodes