The 6.2 release of Kubotek Kosmos VALIDATE has introduced user interface support for CSV files as a derivative point cloud data set. The compare function tests that each point defined in the CSV is on the authority B-Rep model within the specified comparison tolerance and that each face of the B-rep model matches to at least one point.
CSV files are a simple data exchange format commonly used in popular spreadsheet software, which grew in use before attempts at standardization. CSV stands for Comma Separate Values and are generally accepted to be a type of ASCII text file (TXT). This means that they are easily viewed and edited by nearly all text document software including free utilities such as Windows Notepad. Among 3D engineering software, CSV files are expected to include sets of X, Y, Z Cartesian coordinate values on separate lines in the file. With the comma character declared as the delimiter between values, the period character (ie., decimal point, dot, full stop) consistently serves as the decimal separator.
The lack of standards means there is no agreement on whether the first line of the engineering-style CSV file is a header or how comments might be supported. Additionally, the first value on each line is sometimes used as a label or count index. This makes the CSV format a bit like G-code in that there are different “flavors” used by different vendors. Adapting the data to meet the expectations of a specific application can usually be accomplished with any professional code editor.
Software used to collect results from Coordinate Measuring Machines (CMM) is typically based around a database of 3D point locations. For the results to be shared with other 3D engineering programs, this software needs the capability to output sets of X, Y, Z Cartesian coordinate values. Because of its simplicity and flexibility, CSV is a popular file output format for CMM engineering teams. IGES is a standard format that is also commonly used, but not all CMM software supports it.
When suppliers are required to validate translations of the authority 3D CAD data to the CMM software, which is common in North American aerospace supply chains, it is not actually the measurement results data that needs to be validated. What needs to be validated is that the CMM software read the authority CAD model precisely and completely. The best way to do that is for the CMM software to output a standard B-Rep CAD file such as STEP, but that capability is uncommon in CMM software. An alternative method suitable to most supply chain quality representatives is that the CMM program output a set of sample points which the software precisely generates on each face of the nominal CAD model.
That’s where the CSV file comes into use for CAD translation validation. The nominal CSV points, which represent the derivative work product in the CMM process, are compared back to the authority CAD model by software such as Kubotek Kosmos Validate.
Translation validation software from Kubotek has been supporting CSV files for this purpose for many years. Our partner Verisurf has been sending CSV point files into our translation validation software using a command line interface. The enhancement in 6.2 is that this long-used capability is now exposed in the user interface so that CSV files can simply be selected as the derivative file to be compared.
The CSV flavor that is supported by Kubotek Komos Validate 6.2 does not include a header line. The first value on each line of the file is read as a label.