image

Validation Tools & Usage

 

Scenario 1: Point-To-Part Testing The following is one use case scenario of a Point-To-Part Validation.  This method allows TransMagic to be used for both the Translation and Validation of a part:

  • Load the original (preferably native) file that you have received from your customer/vendor into TransMagic.
  • Save the file out into a format that your application will accept.  For the highest quality results you should save the file using the following guidelines in order of preference:
    • Save into the native format if supported by TransMagic such as CATIA V4 or CATIA V5.
    • Save into the native 3D kernel formats that your application is based on such as ACIS *.sat or Parasolid *.x_t.  Many CAD\CAM\CAE applications are based on these two solid modeling kernels.  In terms of geometry, these kernel formats are as native to an application as the applications own format.
    • If neither native nor native kernel formats are available then save to a solid format such as STEP *.step or JT *.jt.
    • Finally if no other solid format is available then save to the IGES *.igs format.
  • Load this file into your application.
  • You will need to use your application to create several points at various locations on the surfaces and edges of the part.  To be a true translation validation, these points need to be generated in the receiving application.  TransMagic could certainly generate points on a part but then of course they’re going to be perfectly ON the part in TransMagic.
  • It’s these points that will be used for the actual translation validation.  Save these points out of your application using the same rules above as these are going to be brought into TransMagic for validation.  Again always use native if TransMagic supports the format, then the 3D kernel formats ACIS *.sat or Parasolid *.x_t, then the solid formats STEP *.stp or JT *.jt and finally IGES if nothing else is supported out of your application.  TransMagic supports the following native application formats:
    • CATIA V4, CATIA V5, Inventor, Pro/E, SolidWorks or UG/NX.
  • Now we’re ready for the point-to-part translation validation using TransMagic:
    • Load the native file into TransMagic.
    • TransMagic needs to be “told” to read in points.  In TransMagic go to File->Settings, then click the format that the points are contained in, i.e. click the “Parasolid (X_T)” tab if you are bringing in a Parasolid *.x_t file.  Check the option that reads “Read Free Points”.  Some formats read in points no matter what – ACIS (SAT) is one of those.
    • Now we need to bring the points into the currently open native file.  Do this by selecting File->Import.  This will import the points into the current document (whereas File->Open would simply open a new document with just the points).
    • To see the points right-click and select Show->Vertices.  The points will all show up now as dots.
    • Click on the part to be verified – it will highlight yellow.
    • Select Geometry->Special->Calculate Points to Parts.
      • You will be prompted to output a log file.  This log file will contain a list of all points and calculated deviations from the part.  This log will also be displayed after the validation is complete.
      • Enter the deviation value you wish to test against.  This value should be set to the highest tolerance in the model.  For example, if the most precise tolerance is +-.001 in. then this is a good measurement to test against.  Click OK.
      • TransMagic will test all the points against the part using a closest point calculation.  If any points are outside of the measured value then these points will be highlighted RED and numbered.  The log file will then be displayed and you can compare the out-of-tolerance points, if any, against the log file to determine if these are in areas of high tolerance or critical areas.
      • Another nice feature of TransMagic’s visual output is the ability to create a 3D View-Only HTML file.  Do this by simply selecting File->Save As and then select the HTML format.  You can save this HTML file along with the Point-To-Part log file as a visual and data record of your part’s validation.

 

 

Scenario 2: Volume Compare Validation

This volume compare validation method allows TransMagic to be used for both the Translation and Validation of a part:

  • Load the original (preferably native) file that you have received from your customer/vendor into TransMagic.
  • Click on the part – it will highlight yellow and then click the “X3” icon.  This will calculate the volume of the part along with multiple other mass properties.  You can either write down this figure or select the “Copy to Clipboard” button on the Mass Properties dialog.  We’ll be using this figure later.
  • Save the file out into a format that your application will accept.  For the highest quality results you should save the file using the following guidelines in order of preference:
    • Save into the native format if supported by TransMagic such as CATIA V4 or CATIA V5.
    • Save into the native 3D kernel formats that your application is based on such as ACIS *.sat or Parasolid *.x_t.  Many CAD\CAM\CAE applications are based on these two solid modeling kernels.  In terms of geometry, these kernel formats are as native to an application as the applications own format.
    • If neither native nor native kernel formats are available then save to a solid format such as STEP *.step or JT *.jt.
    • Finally if no other solid format is available then save to the IGES *.igs format.
  • Load this file into your application.
  • Calculate the volume of this part in your application and take note of this value.
  • Compare the volume values from the original part in TransMagic vs. the values of the part as calculated by your application:
    • A deviation of 2% for volume calculations is a good mean range to qualify a translation as accurate.  However, keep in mind that for parts as small as a thimble 1% would qualify as an accurate translation and for parts of a very large scale > 2% could qualify as an accurate translation.

 

 

Scenario 3: Surface Area Compare Validation

This surface area compare validation method allows TransMagic to be used for both the Translation and Validation of a part:

  • Load the original (preferably native) file that you have received from your customer/vendor into TransMagic.
  • Click on the part – it will highlight yellow and then click the “X2” icon.  This will calculate the surface area of the part.  Write this figure down.  We’ll be using this figure later.
  • Save the file out into a format that your application will accept.  For the highest quality results you should save the file using the following guidelines in order of preference:
    • Save into the native format if supported by TransMagic such as CATIA V4 or CATIA V5.
    • Save into the native 3D kernel formats that your application is based on such as ACIS *.sat or Parasolid *.x_t.  Many CAD\CAM\CAE applications are based on these two solid modeling kernels.  In terms of geometry, these kernel formats are as native to an application as the applications own format.
    • If neither native nor native kernel formats are available then save to a solid format such as STEP *.step or JT *.jt.
    • Finally if no other solid format is available then save to the IGES *.igs format.
  • Load this file into your application.
  • Calculate the surface area of this part in your application and take note of this value.
  • Compare the volume values from the original part in TransMagic vs. the values of the part as calculated by your application:
    • If you’re within a 1% Surface Area deviation, that is a highly accurate translation.  For example a .002 sq. in. Surface Area deviation may equate to a maximum tolerance deviation of only .000004 in. on a single surface somewhere in the part.  Analytic surfaces such as planes, cones, spheres, tori, cylinders etc. are extremely accurate as TransMagic performs straight analytic to analytic mapping.  So most deviations will be in “free-form” surfaces such as spline surfaces.

 

 

TransMagic Stated Geometric Tolerance Specification:

We have a mandate called the "TransMagic Stated Geometric Tolerance Specification" regarding TransMagic’s translation precision.  It reads as follows:

 

Analytic Surfaces

Analytic surfaces are converted to a precision of zero or machine tolerance.  This means that where-ever an analytic surface is present, such as a cone, sphere, plane, torus, etc. we will convert it to an analytic surface in TransMagic with an identical surface.

 

Free-Form Spline Surfaces

For free-form spline surfaces such as NUBs, NURBs, Bezier, etc. the geometry internal to the surface is translated at a precision of 10e-6mm - which is an extremely tight tolerance and also essentially zero.  In fact this value, 10e-6mm, is the value that TransMagic considers zero (.000001 = 0).

 

Trim Boundaries

Trim boundaries are precise to exactly what they are in the original file.  Depending on the file, this can be anywhere from .1 mm to zero. TransMagic will translate what-ever is in the CAD file. Meaning that if a CAD model is generated at a very loose tolerance (very common in V4); we will simply translate at that tolerance.

 

Class A Surfaces

For Class A surfaces, this refers to a mathematic curvature continuity of the second derivative (C2) between two surfaces.  This means that the two surfaces have identical speed, direction and radius of curvature at their boundary.  This allows two different surfaces to appear as though they are the same surface when subjected to visual inspection and testing such as light reflection line testing.  If the math is present to support C2 continuity or even G2 continuity (geometric continuity of the second derivative) then TransMagic will absolutely support and translate that continuity.  Note however, that C2 or even G2 is fairly uncommon except in automotive and aerospace sheet-metal applications.  The data weight required to support true C2/G2 is pretty high and these surfaces are typically generated by a dedicated add-on to most CAD systems.  Most 
continuity math found in the surface boundaries in any given CAD file is C1 or G1 - this is usually the curvature associated with blend radii and lofting/sweeping operations.  C1 means that the two surfaces have identical speed and parallel radius of curvature (but not identical).  This is a much lighter data representation and yet still looks very pleasing to the eye.  In any case as will all math data contained in any format that TransMagic supports - TransMagic will simply support what is represented in the original CAD model.

 

Bezier Surfaces

Some antiquated CAD systems use Bezier surfaces vs. the current industry standard NURBs surfaces, an example being CATIA V4.  TransMagic's math engine is based on NURBs and analytics so a conversion must be done between Bezier and NURBs to bring such files into TransMagic and vice versa for files being saved out of TransMagic.  There is more than one way to perform this conversion and TransMagic has spent a significant amount of resources developing the mathematic algorithms to perform this conversion to our stated tolerances consistently and reliably.  In fact in the case of CATIA V4, TransMagic has numerous CATIA V5 customers who have chosen TransMagic for its CATIA V4 import into CATIA V5 as TransMagic's conversion is more consistent and reliable than CATIA V5's own CATIA V4 translator.  Note also that when an application such as CATIA V4 outputs an IGES file for example they themselves are still performing this conversion and the results are quite literally always sub-standard when compared to TransMagic's mathematic conversion on a native CATIA V4 file.

 

In summary

TransMagic will translate original geometry at the same tolerance as the original geometry. - TransMagic will keep intact the mathematic definition of Class A surface boundaries when they are present or more precisely, TransMagic supports and will keep intact the mathematic boundary condition of the original model regardless of its class.  TransMagic includes technology (Full Repair) to actually generate more precise intersections (boundary conditions) but this is and will always be a user's decision to use this technology to do so.


 

Click here for a PDF version of this guide: Using TransMagic For Validation