8.101. Point Sample Triangle Geometry
Group (Subgroup)
DREAM3D Review (Geometry)
Description
This Filter randomly samples point locations on Triangles in a Triangle Geometry. The sampled point locations are then used to construct a Vertex Geometry. The number of point samples may either be specified manually or by inferring from another Geometry:
Geometry |
Source for Number of Samples |
|---|---|
Image |
Number of cells |
Rectilinear Grid |
Number of cells |
Vertex |
Number of vertices |
Edge |
Number of vertices |
Triangle |
Number of vertices |
Quadrilateral |
Number of vertices |
Tetrahedral |
Number of vertices |
In order to ensure an even sampling of the total surface are of the Triangle Geometry, the average number of points sampled per triangle is made proportional to the area of the triangle. Within a given Triangle, a point is chosen using the following approach:
where 
are the coordinates of the sampled point; 
, 
, and 
are the coordinates of the vertices beloning to the Triangle; and 
and 
are random real numbers on the interval 
. This approach has the benefit of uniform sampling within the Triangle area, and functions correctly regardless of the dimensionality of the space embedding (i.e., whether the Triangle is in the plane or embedded in 3D).
The user may opt to use a mask to prevent certain Triangles from being sampled; where the mask is false, the Triangle will not be sampled. Additionally, the user may choose any number of Face Attribute Arrays to transfer to the created Vertex Geometry. The vertices in the new Vertex Geometry will gain the values of the Faces from which they were sampled.
Input Parameter(s)
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Number of Sample Points |
Scalar Value |
Int32 |
The number of sample points to use |
Optional Data Mask
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Use Mask Array |
Bool |
Specifies whether or not to use a mask array |
|
Mask Array |
Array Selection |
Allowed Types: uint8, boolean Comp. Shape: 1 |
DataPath to the boolean mask array. Values that are true will mark that cell/point as usable. |
Random Number Seed Parameters
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Use Seed for Random Generation |
Bool |
When true the user will be able to put in a seed for random generation |
|
Seed Value |
Scalar Value |
UInt64 |
The seed fed into the random generator |
Stored Seed Value Array Name |
DataObjectName |
Name of array holding the seed value |
Input Triangle Geometry
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Triangle Geometry to Sample |
Geometry Selection |
Triangle |
The complete path to the triangle Geometry from which to sample |
Input Triangle Face Data
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Face Areas |
Array Selection |
Allowed Types: float64 Comp. Shape: 1 |
The complete path to the array specifying the area of each Face |
Face Attribute Arrays to Transfer |
MultiArraySelection |
The paths to the Face Attribute Arrays to transfer to the created Vertex Geometry where the mask is false, if Use Mask is checked |
Output Vertex Geometry
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Vertex Geometry Name |
DataGroupCreation |
The complete path to the DataGroup holding the Vertex Geometry that represents the sampling points |
Output Vertex Attribute Matrix
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Vertex Data |
DataObjectName |
The complete path to the vertex data arrays for the Vertex Geometry |
Example Pipelines
License & Copyright
Please see the description file distributed with this plugin.
DREAM3D-NX Help
If you need help, need to file a bug report or want to request a new feature, please head over to the DREAM3DNX-Issues GitHub site where the community of DREAM3D-NX users can help answer your questions.