nanoCAD 3DScan Help

Texturing and Calcultions

Generating Raster from Point Cloud

CAD drafting Texturing and Calcultions 0 Ribbon: 3DScan > Texturing and Calculations > CAD software Texturing and Calcultions 1 Point Cloud To Raster

CAD drawing Texturing and Calcultions 2 Menu: 3DScan > Texturing > CAD drafting Texturing and Calcultions 3 Point Cloud To Raster

CAD software Texturing and Calcultions 4 Toolbar: Meshes 3DScan > CAD drawing Texturing and Calcultions 5 Point Cloud To Raster

CAD drafting Texturing and Calcultions 6 Command line: PC_GENERATE_RASTER_FROM_CLOUD

This command is designed to create a raster image with a georeferencing file from a point cloud. The attribute values of the cloud points are used to create the raster image. The pixel value is determined based on the attribute values of the cloud points that fall within a pixel of a given size. The attributes that define the coloring type can be: Height and Intensity.

The supported formats for creating a raster image are BMP, JPG, PNG, and GeoTIFF. When selecting BMP, JPG, or PNG formats, the georeferencing file is created by default; when selecting GeoTIFF, the geospatial data is entered into the corresponding geotags, but it is also possible to create a separate georeferencing file; to do this, select GeoTIFF + TFW. The extension of the georeferencing file is formed from the extension of the raster image according to the rule: the first letter of the raster extension, the last letter of the raster extension, w. For example, for a PNG raster image, a georeferencing file with the extension PGW will be created. The generated raster image is georeferenced to the world coordinate system.

When height is selected as the attribute, the generated raster image is a real value image (float64 type), and when intensity is selected, it is an integer, single-channel 8-bit image. Since only GeoTIFF supports real values from the specified formats, when selecting height as the attribute, you can specify either GeoTIFF or GeoTIFF + TFW. Integer values are supported by all specified formats, and for GeoTIFF there is also the option to save georeferencing coefficients either only in tags or in tags and in a separate file.

For heights and intensities, the raster image generation occurs in two stages. The first stage is mandatory and includes generating pixel values for the cloud points. The second stage is optional and allows for interpolation of those pixels that were not covered by the cloud points, in other words, it allows for interpolation of voids.

After running the command, specify the Point Cloud object in the drawing. The selected point cloud should have a Class attribute in order to be able to use the classification procedures.

The command parameters are set in the Properties bar.

Parameters:

Color by	Defines the cloud attribute whose values will determine the pixel values. Height - the heights of the cloud points will be used to form the pixel values. Intensity - the intensities of the cloud points will be used to form the pixel values.
Source classes	The source cloud classes whose points will participate in generating of the raster image.
Pixel size	The pixel size in drawing units. The resolution of the output file depends on it. Reducing the pixel size increases processing time.
No data	The value of a pixel for which no attribute value has been extracted from the point cloud. In other words, the value of a pixel that was not covered by any points from the point cloud (empty pixels). For intensities, the value is limited from below by 0 and from above by 255.
Data value	Defines the algorithm for selecting the pixel value – which attribute value of the points that fall on the pixel will be taken. Four selection options: Mean – the mean value of the attribute of all points that fall on the pixel; Min – the minimum value of the attribute of all points that fall on the pixel; Max – the maximum value of the attribute of all points that fall on the pixel; Median – the median of the attribute values of all points that fall on the pixel.
Trust one point	A parameter that allows, if a single cloud point falls on a pixel, to use its attribute value for the output pixel value. Options: Yes – if only one point falls on the pixel, its attribute value will be assigned to the pixel; No – the pixel will remain empty (with a No data value).
Trust two points	A parameter that allows, if two cloud points fall on a pixel, to use their attribute values for the output pixel value. Options: Yes – if only two points fall on the pixel, the output pixel value will be formed from their values depending on the option in the Data Value parameter, but only if the difference between the values is greater than or equal to the threshold specified in the appearing Difference Value parameter; No – the pixel will remain empty (with a No data value).
Difference value	Determines the threshold for the case when two cloud points fall on a single pixel. Available only when Yes is selected in the Trust two points parameter.
Interpolate emptiness	Allows interpolation based on neighboring pixels for pixels that do not contain cloud points. Two options are available: Yes - interpolate empty spaces, No - do not interpolate empty spaces. If Yes is selected, other parameters appear (Interpolation section) that affect the interpolation result.
Neighbors count	The interpolation parameter, which specifies the number of neighbors around the interpolated pixel, whose values will be used to calculate the output value. Possible values are 4, 8, and 16 – this determines the number of zones in which the nearest pixels will be searched. If the number of found neighbors is less than the value specified in the Minimal number of neighbors parameter, the pixel remains empty (with a No data value).
Minimal number of neighbors for interpolation	The interpolation parameter, which determines the minimum number of neighbors for the interpolated pixel. If the number of found neighbors is less than the specified value, the pixel remains empty (with a No data value). The parameter values are limited from below by 1 and from above by 16.
Interpolation radius	A parameter that specifies the neighborhood radius in the raster image for searching the nearest neighbors. The values are limited from below by 1.
Smoothing degree	A parameter that affects smoothing during interpolation. The values are limited from below by 1 and from above by 8.
Apply median filtration	Allows you to apply median filtration to the interpolated image to suppress noise.
Suffix	Allows you to specify a suffix for the output file names.
Format	Allows you to select the raster image format. When selecting the coloring method by heights, there are two options: GeoTIFF and GeoTIFF + TFW. When selecting by intensities, there are five options: BMP, JPG, PNG, GeoTIFF, GeoTIFF + TFW.