Triangulation File Utilities

Function

This command allows you to modify TIN surfaces in a variety of different ways, then allows for 3d viewing and shading of the modified surface and finally for saving the file with a choice of output formats.  The focus of the routine is to elevate or lower the TIN or selected areas within the TIN, merge TINs with other surfaces, or use data from other TIN files to apply to the current TIN.  Operations can be performed on the entire TIN or just on user selected Inclusion and/or Exclusion areas.  The routine will automatically rework the TIN network for conformation to a selected boundary, say a building outline.  In the case of said building, a value of 10 could be subtracted from the building outline. This will drop all of the triangulation within the outline by 10', thus creating a model of the excavated area for the building.  The modified TIN can then be saved to a new file, which could be used to compute an excavation volume with Volumes by Triangulation.  This routine does not allow for manual reconfiguration of the TIN network.  This is performed under Surface Tools, also in the Contour pulldown menu.  This routine also includes conversions to and from TIN files, DXF files and 3D Face entities.

Begin with the dialog shown here. First select a TIN model.  You may choose between an .flt or .tin file, a DXF file (that includes 3DFACE entities), or 3DFACE entities in the current drawing. Specify the subject area by choosing inclusion or exclusion perimeters, then press the next button.

Load TIN File: Allows you to specify a triangulation (.flt or .tin) file to load.

Load DXF File: Allows you to specify a DXF file to load. Only loads 3DFACE entities from the selected DXF file.

Select 3D Faces: Allows you to select 3DFACE entities from the current drawing.  This also includes rectangular 3d faces from a plotted grid.

Pick Bounding Polylines: Allows you to select any inclusion/exclusion perimeter(s).  When this button is selected, the user is taken back to the drawing and prompted to select the perimeters.  Press Enter when the selections are finished to return back to the dialog.

Fast TIN Intersect: When checked, this command will not try and intersect 3DFACE entities.

Fill-in-holes: When checked, any missing triangulation or gap in the surface will be automatically filled in with additional triangles.  This option has to set before loading the TIN file to take effect.

Next: Press this button to proceed to the next dialog after all selections have been made .

The next dialog allows you to perform mathematical operation(s) on the loaded TIN. Each operation is described below. Keep in mind that generally these operations are to be performed on an area inside your inclusion perimeter (but excluding anything inside your exclusion perimeters). If you





do not specify any perimeters, the desired operation/s will be performed on the entire TIN.

Elev-Value: Specify either an elevation or value depending on the operation.   The value specified will be used for subsequent operations.

Set New Elevation: Sets all TIN faces in the subject area to the elevation specified in the Elev-Value field.

Set NULL's to Elevation: Sets all NULL values in the subject area to the elevation specified in the Elev-Value field.

Set Elevation's to NULL: Sets all of the elevation values in the subject area to NULL.

Set Elevation by Surface: Sets all TIN faces within the subject area to the elevations from a second surface file within the same area. You will be prompted to select a second TIN file or grid file. Only areas common to both surfaces will be applied to the subject TIN.

Add: Adds the value specified in the Elev-Value field to the subject area of the TIN.

Subtract: Subtracts the value specified in the Elev-Value field to the subject area of the TIN.

Multiply: Multiplies by the value specified in the Elev-Value field to the subject area of the TIN.

Divide: Divides by the value specified in the Elev-Value field to the subject area of the TIN.

Offset: Performs a perpendicular offset of the TIN surface by the specified amount.

Tolerance: This setting is used by the Simplify command described below. Specify the maximum average distance that any point can be moved outside of the plane of any triangle that connects to that point. Values might range from .01 to .1 for most purposes.

Simplify: Causes edges within the Tin mesh to be collapsed to reduce the number of triangles, edges, and points within the mesh while having a minimal impact on the overall shape of the mesh.

Add TIN: Raises the subject area of the current TIN by the elevation value from a second user selected TIN file.  This function is most applicable to applying a strata thickness TIN.

Subtract TIN: Lowers the subject area of the current TIN by the elevation value from a second user selected TIN file.

Min TIN: This does a comparison between the current TIN and a second user selected TIN file, and applies the lower value of the two TINs to the subject area.

Insides:  If this is the only option checked, only changes made within the inclusion perimeter will be saved.  TIN entities outside of the perimeter will not be saved.

Border:

Outsides:  If this is the only option checked, TIN entities inside of the inclusion perimeter will not be saved.  Everything outside of the perimeter will be saved.

SaveAs TIN: Saves the current TIN as an .flt or .tin file.

SaveAs DXF: Saves the current TIN as a DXF file. This format can be used by many other CAD
programs.

Draw As 3DFaces: Draws the current TIN as 3D Faces in the current viewport.  The Layer window is used to specify the layer that the faces will be created in.

This icon converts the right mouse button to a zoom function.  Hold the button down and move the mouse up or down to zoom in and out.


This icon converts the right mouse button to a rotate function.  Hold the button down to rotate the view in any X, Y or Z direction.  When the XY appears in the window, the rotation will occur relative to the XY axis.  When the mouse is moved toward the outer perimeter of the window, the XY will change to a Z.  Holding the button down while the Z is visible will rotate the drawing on the Z axis.


This icon converts the right mouse button to a pan function.  Hold down on the button while moving the mouse to pan.  Holding down the mouse wheel will also serve as a pan function in any of the above modes.


This icon toggles shading on and off.


This icon restores the graphics to plan view.


This icon reverses the effects of all operations performed on the TIN and reverts it back to its original status.


This icon exits the routine. If the TIN has been modified, you will be prompted to save.

Pull-Down Menu Location: Tools-> Surface Tools

Prerequisite: 3D Faces, a TIN file or a DXF file.

Keyboard Command: TINUTIL