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File formats


Rhino Bezier surface file as written with the OpenNurbs library. Rhino can be used to write surface files which can be read by most CAD programs.


VSP uses its own file format for airfoil points. Some example airfoil files are included in the 'airfoils' directory of the distribution. The example file representing a NACA 23015 is included below.

The file starts out with a simple header. The first line is a comment field, it is unused by VSP. The second line is the airfoil name which will be displayed in VSP. The third line is a flag to indicate a symmetrical airfoil. The fourth and fifth lines specify the number of points which define the upper and lower surfaces.

The surfaces are given as a series of (x, y) pairs. The top surface first, then the bottom surface. Points are specified from leading edge to trailing edge. There is a blank line between the two sets of points.

Typically, the leading edge will be at (0, 0) and the trailing edge at (1, 0). However, VSP does not check or enforce this. Airfoils with points which extend beyond the x-range of [0, 1] can be used to model high lift systems.

NACA 23015
0       Sym Flag (0 - No, 1 - Yes)
18      Num Pnts Upper
18      Num Pnts Lower
0.0000  0.0000
0.0125  0.0334
0.0250  0.0444
0.0500  0.0589
0.0750  0.0690
0.1000  0.0764
0.1500  0.0852
0.2000  0.0892
0.2500  0.0908
0.3000  0.0905
0.4000  0.0859
0.5000  0.0774
0.6000  0.0661
0.7000  0.0525
0.8000  0.0373
0.9000  0.0204
0.9500  0.0112
1.00000 0.0000

0.0000  -0.0000
0.0125  -0.0154
0.0250  -0.0225
0.0500  -0.0304
0.0750  -0.0361
0.1000  -0.0409
0.1500  -0.0484
0.2000  -0.0541
0.2500  -0.0578
0.3000  -0.0596
0.4000  -0.0592
0.5000  -0.0550
0.6000  -0.0481
0.7000  -0.0391
0.8000  -0.0283
0.9000  -0.0159
0.9500  -0.0090
1.00000 -0.0000


Document cabin layout file here.


Open source Calculix FEA program. Calculix files are identical in format to those used by ABAQUS.


Vorlax case file describing the flight condition and solver parameters to be used for analysis.


Comma delimited text file reporting wetted areas and volumes output from CompGeom.


File to be used with the Felisa unstructured volume grid generator and flow solver.


VSP uses its own file format for fuselage cross sections. An example cross section file is included in the 'fuselage' directory of the distribution. The example file representing a square box is included below.

The file starts out with a simple header. The first line is a comment field, it is unused by VSP. The second line is the cross section name which will be displayed in VSP. The third line is the number of points in the cross section definition.

After the header, there is a list of (x, y) pairs for the points which define the cross section. Only the positive-x half of the fuselage shape is specified – symmetry is assumed. Points are specified in clockwise order.

VSP will allow you to scale the height and width of a fuselage section defined by the points in the file.

VSP will fit a smooth surface through the specified points. This smoothing can make sharp corners problematic. In the example below, points were clustered near the corners to try to help VSP represent the corners.

17      NumPnts
0       1
0.5     1
0.7     1
0.9     1
0.98    0.98
1       0.9
1       0.7
1       0.5
1       0
1       -0.5
1       -0.7
1       -0.9
0.98    -0.98
0.9     -1
0.7     -1
0.5     -1
0       -1


XSec Hermite wireframe file


Vorlax input file.


VSP uses industry standard JPEG files for input and output of images.

The two main uses of JPEG images in VSP are to save a copy of the display window and display a background image on the display window. The background image may be a beautiful sunset or a 3-view drawing to match the model.

Background images can also be displayed when editing a fuselage cross section. Finally, JPEG images can be used as textures applied to the surface of the model.


Gmsh is an open source mesh generator. VSP surface triangulations may be written to MSH format to be read by Gmsh.


NASCART-GT is a Cartesian unstructured Navier Stokes CFD code. VSP can work with NASCART bodyin.dat geometry files.


Reasonably standardized triangulated surface file format.


Surface file used as input for TetGen.


VSP's own trimmed surface file format. This file approaches all of the information required for a formal BREP representation of a geometry.


ASCII stereolithography file for triangulated surfaces. The lingua-franca of triangulated surfaces. Although they are rather limited, almost everything can work with STL files.

The STL file format can not identify which component each triangle is associated with. Consequently, the STL file format can only represent a single watertight surface.

STL files do not natively store connectivity between triangles. Since many programs need this connectivity information, they must re-build the connectivity by checking point proximity. For some models, this process can introduce topological problems with the model.

STL files contain a large amount of redundant information. Consequently, they can be very large for a given model – as much as six times the size of other ASCII formats.


VSP can use TARGA image files as textures applied to the models. TGA files support transparency, which can be very handy when making non-repeating textures.


Cart3D surface triangulation format. TRI files are documented here.

VSP can output three kinds of triangulated surfaces to Cart3D.

  1. Unintersected components (Configuration)
  2. Intersected components (Wetted Surface)
  3. Isotropic surface mesh (Wetted Surface)


  • Drag buildup report (tsv)


  • Automation script (txt)
  • Wetted area/volume report (txt, csv)
  • Area ruling report (txt)
  • Mass properties report (txt)


Native VSP parametric geometry definition. The VSP file is saved in XML format and can be relatively easily read, parsed, and updated.

files.1327181241.txt.gz · Last modified: 2018/04/01 14:40 (external edit)