ILasSurface.AsTin Method

Export to TIN.

[Visual Basic .NET]
Public Function AsTin ( _
    ByVal pTrackCancel As ITrackCancel, _
    ByVal pFilter As ILasFilter, _
    ByVal Resolution As Double, _
    ByVal Method As esriTinPointSelectionMethod, _
    ByVal ZFactor As Double _
) As ITin

[C#]
public ITin AsTin (
    ITrackCancel pTrackCancel,
    ILasFilter pFilter,
    double Resolution,
    esriTinPointSelectionMethod Method,
    double ZFactor
);

[C++]
HRESULT AsTin(
  ITrackCancel* pTrackCancel,
  ILasFilter* pFilter,
  double Resolution,
  esriTinPointSelectionMethod Method,
  double ZFactor
);

[C++]
Parameters
pTrackCancel [in]

  pTrackCancel is a parameter of type ITrackCancel*
pFilter [in]

  pFilter is a parameter of type ILasFilter*
Resolution [in]

  Resolution is a parameter of type double
Method [in]

  Method is a parameter of type esriTinPointSelectionMethod
ZFactor [in]

  ZFactor is a parameter of type double

Product Availability

Description

Converts the las dataset to a TIN.

pTrackCancel references a CancelTracker that can be used to stop the process. This can be set to NULL if the ability for the user to cancel isn't required.

pFilter references aLasFilter that defines the selection criteria for what points to use from the las files. The area of interest (AOI) of the filter defines the extent of the TIN to extract. The Spatial reference of the AOI detemines the spatial reference of the output. This means a projection is applied if it differs from the las dataset. Projection is expensive and should be avoided where possible.

Resolution is a double. It's meaning is controlled by Method. When Method is set to random then Resolution is a thinning factor and you should provide a value &> 0 and &less or equal 1. In this case, when multiplied by 100 it represents the percentage of points from the las files to triangulate. When Method is set to min, max, or average then Resolution is the bin size, or horizontal sample distance, used for filtering. The value should be given in XY units of the data.

Method is theesriTinPointSelectionMethod used to control which thinning method is used. Random uses a truly random sample from the las files. The other three methods are based on binning. The points that are the highest or lowest in their bins, or closest to the average in their bins, are used in the output TIN.

zFactor is used to convert z values from one unit of measure to another. The output node z values are multipled by the zFactor. Starting at 10.6 the zFactor is ignored if the software can determine what factor to apply based on the input and output VCS. Note, each reference las file may have a different VCS (or none at all), and the output spatial reference (with optional VCS) is set via the filter AOI.

Notes:

To retrieve full resolution data with no thinning set the Method to random and Resolution to 1.

The output TIN will have an extent larger than the requested AOI. This is because the system includes points surrounding the AOI to ensure the surface within it is fully defined. It's up to the caller to clip the resulting TIN to the AOI or ensure only the area within the AOI is used for analysis.

You should generally not try to create TINs larger than a few million points. Set appropriate filter (including area of interest), resolution, and method properties to limit the size of the output TIN. This method will raise an exception if the resulting TIN is too large.

Remarks

See Also

ILasSurface Interface