10.27. Compute Feature Centroids from Triangle Geometry
Group (Subgroup)
Statistics (Morphological)
Description
This filter computes the centroid (the average position of the bounding nodes) of each Feature in a Triangle Geometry (a surface mesh built from triangles).
In a surface mesh, each triangle carries a Face Labels value: a pair of Feature Ids naming the two features that meet at that triangle. These two features are the triangle’s “owners”. A Feature is the volume of material enclosed by the triangles that reference its Id. The corner points of each triangle are its nodes (also called vertices).
The centroid of each feature is determined as follows:
For each triangle, read its two owners from the Face Labels array.
Add the 3 nodes of that triangle to the set of nodes bounding each of those two owners. A set stores each node only once per owner, so shared nodes are not double-counted.
For each Feature, average the (x, y, z) coordinates of the set of nodes that bound it to obtain the centroid.
Boundary / Exterior Label
A Face Labels value of -1 indicates the exterior of the sample (the triangle faces open space rather than another feature). Feature Id -1 is the exterior and is not a real feature; its accumulated “centroid” entry is therefore not physically meaningful and should be ignored.
Units
Centroid coordinates are reported in the geometry length units of the Triangle Geometry vertices (for example, micrometers if the mesh coordinates are stored in micrometers).
Required Input Sources
Triangle Geometry – a surface mesh, typically produced by a surface-meshing filter such as Create Surface Mesh (Surface Nets) or Create Surface Mesh (QuickMesh).
Face Labels – the per-triangle pair of Feature Ids, produced alongside the mesh by Create Surface Mesh (QuickMesh) or Create Surface Mesh (Surface Nets).
Filter Parameters
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Triangle Geometry |
Geometry Selection |
Triangle |
The complete path to the Geometry for which to calculate the normals |
Input Triangle Face Data
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Face Labels |
Array Selection |
Allowed Types: int32 Comp. Shape: 2 |
The DataPath to the FaceLabels values. |
Input Face Feature Data
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Face Feature Attribute Matrix |
AttributeMatrixSelection |
The DataPath to the AttributeMatrix that holds feature data for the faces |
Output Face Feature Data
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Calculated Centroids |
DataObjectName |
Centroid values created in the Face Feature Data |
|
Is Periodic |
Bool |
Should segment features wrap around the image data |
License & Copyright
Please see the description file distributed with this Plugin
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