Data Type: Point Cloud ()

Description:

Data objects of type Point Cloud are used to represent sets of 3D points with additional data variables associated with them. For each point, at least the x-, y-, and z-coordinates as well as an additional id are stored. The id is an arbitrary number which can be used to identify corresponding points in different data sets. Note that the id is to be distinguished from the index of each vertex which refers to the internal consecutive numbering of the vertices.

For each point an arbitrary number of additional data columns may be defined. The elements of a data column may be stored as 32-bit floats, as 32-bit integers, or as 8-bit characters. Each data column also has a string specifying its name. Data columns are consecutively numbered starting with 0. Optionally, a symbol may be defined, which is used to denote the column in an arithmetic filter expression as provided by the modules Point Cloud View and Point Cloud Difference.

Finally, for each data point one or more text labels can be specified. As with data columns, label columns have a name and are consecutively numbered starting with 0. Labels can be displayed using Point Cloud Labels.

Commands:

computeBounds
Computes the bounding box of the point cloud.

computeConnectivity
Computes connectivity information required to display bonds between neighboring points. Bond detection does not take into account any chemical information. Instead, merely nearest neighbors are computed. Each point may have at most 12 such neighbors. In addition the length of the longest bond of a point may not be larger than 1.4 times the length of the shortest one.

addPoint <x> <y> <z>
Adds a new point to the point cloud. The arguments are the three coordinates. The new point will be assigned the id 0. The command returns the index of the new point.

removePoint <index>
Removes a point from the point cloud. The index is passed as argument.

resetIds
Resets the ids of all points so that they are equal to the respective point indices.

setId <index> <id>
Sets the id of the point specified by index.

getId <index>
Returns the id of the point specified by index.

getIndex <id>
Returns a list of the indices of all points with the specified id. This method performs a linear search over all points and thus is slow.

clear
Deletes all points and sets the number of data columns to zero.

setNumDataColumns <number_of_columns>
Set the number of data values that are stored for each point. The number of data columns is passed as argument. If the number is less than the number of existing data columns, trailing columns are removed. If the number is greater than the number of existing data columns, empty columns are added.

getNumDataColumns
Returns the number of data columns, i.e., the number of data values per point.

setDataValue <column> <index> <value>
Sets the value of a point in a data column.

getDataValue <column> <index>
Returns the value of a point from a data column.

setDataColumnName <column> <name>
Sets the name of a data column.

getDataColumnName <column>
Returns the name of a data column.

setNumLabelColumns <number_of_columns>
Create and add label columns. The number of label columns is passed as argument. If the number is less than the number of existing label columns, trailing columns are removed. If the number is greater than the number of existing label columns, empty columns are added.

getNumLabelColumns
Get the number of labels that are stored for each point.

setLabelValue <column> <index> <string>
Sets the label of a point in a label column.

getLabelValue <column> <index>
Returns the label of a point from a label column.

setLabelColumnName <column> <name>
Sets the name of a label column.

getLabelColumnName <column>
Returns the name of a label column.