pointCloud Import of point cloud data.
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DESCRIPTION/NOTES
This function creates an object instance of the pointCloud class. For
a listing of available attributes and methods for the pointCloud class
run 'doc pointCloud'.
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INPUT
1 [pcData]
Point cloud input data defined as:
a PATH TO A POINT CLOUD FILE
Absolute or relative path to a:
1 PLAIN TEXT FILE
Column oriented text file where each row correspondonds to one
point. The first 3 columns contain the point coordinates x, y
and z. Further columns can be used for point attributes (e.g.
color values r, g and b). Two possibilities exist to define the
names of the attributes:
* by using the parameter 'Attributes' (see below)
* by defining the attribute names in the first line of the
file using the following format:
'# columns: x y z attributeName1 attributeName2 ...'
2 BINARY FILE
In binary files all values have to be stored in double precision
(i.e. 8 bytes per value). All values are stored sequentially
(e.g. for two points with one attribute the ordering would be
x1, y1, z1, a1, x2, y2, z2, a2).
3 LAS/LAZ FILE
For reading las or laz files the function 'las2mat' must be
accessible on the path. It can be downloaded here:
https://github.com/plitkey/matlas_tools
4 ODM FILE
Files created with OPALS (http://geo.tuwien.ac.at/opals). For
this it is necessary to:
1) Install OPALS
2) Add '%opals_root%\opals' to the search path in Matlab.
Note: with the 'Filter' parameter, an odm filter string can be
applied during the import.
5 PLY FILE
Polygon file format, either in ascii or binary format.
6 MAT FILE
This method can also be used to load a mat file generated with
the 'save' method of this class. For more details run
'help pointCloud.save'.
b MATRIX CONTAINING POINT CLOUD DATA
A matrix of size n-by-3+a. Each row corresponds to one point, i.e.
n is the total number of points. The first 3 columns contain the
point coordinates x, y and z. Further columns can be used for
point attributes (e.g. color values r, g and b). To import these
attributes the parameter 'Attributes' has to be defined (see
below).
2 ['Attributes', attributes]
Name of attributes contained in input data defined as 1-by-a cell,
where a denotes the number of attributes. Predefined attribute names
to use for extended functionality:
* 'nx' = normal x component
* 'ny' = normal x component
* 'nz' = normal z component
* 'r' = color red component
* 'g' = color green component
* 'b' = color blue component
* 'roughness' = roughness in point neighborhood
Imported attributes are saved into the property A of the pointCloud
object, i.e. obj.A.
Additionally, for LAS/LAZ, ODM and PLY files the following applies:
- If the parameter 'Attributes' is not defined by the user, all
non-empty attributes are imported.
- If the name of one or more attribute is specified by the parameter
'Attributes', only these are imported.
- If the parameter 'Attributes' is set to an empty cell, i.e. {}, NO
attributes are imported.
3 ['Label', label]
Label of point cloud defined as a string. If no label is defined and
input is a file path, the file name is used as label.
4 ['RedPoi', redPoi]
Coordinate reduction point defined as vector with 3 elements. The
reduction point defines the origin of a local coordinate system in
which the points are stored.
5 ['HeaderLines', headerLines]
Number of header lines (=rows) to be skipped, if a plain text file
is used as point cloud input.
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OUTPUT
1 [obj]
Object instance of class pointCloud.
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EXAMPLES
1 Import a point cloud without attributes.
pc = pointCloud('Lion.xyz');
pc.plot;
2 Import a point cloud with attributes.
pc = pointCloud('Gieszkanne.xyz', 'Attributes', {'r' 'g' 'b'});
% Attributes are now accessible in the object property pc.A
pc.plot('Color', 'rgb', 'MarkerSize', 5);
3 Import a point cloud from a matrix.
[x, y, z] = sphere(100);
x = x(:); y = y(:); z = z(:);
pc = pointCloud([x y z], 'Label', 'sphere');
pc.plot('MarkerSize', 5);
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philipp.glira@gmail.com
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