The conflation method defines the algorithm used to assign elevation values to output features. Currently there are four built-in conflation methods:

Drape
The Drape method drapes the input geometry over a TIN surface created from LAS points. A z value is stored with each vertex. A vertex is created for each intersection the input geometry has with the triangles in the TIN surface. Therefore, the number of vertices in the output geometry can be much greater than in the incoming geometry.

Learn more about the Drape Conflation Method

Downstream Constraint
The Downstream Constraint method first drapes the input geometry over a TIN surface created from LAS points and then forces the z values in the output geometry in a downstream direction. This method is useful for creating breaklines that hydrologically enforce streams in a downhill direction.

The algorithm used to employ the downstream or upstream constraint is directionally biased. If the line is drawn in a general downstream direction (i.e., 'from point' is higher than the 'to point'), the z values on the output line will lower the draped values producing a "burning" effect (i.e., cut through the terrain surface that is noisy). If the line is drawn in a upstream direction ('from point' is lower than 'to point'), the z values on the output line are raised from the draped values. The 'from' and 'to' point elevation values will always be guaranteed to be equal to the draped surface values from the TIN surface (i.e., not modified by the constraining algorithm).

Learn more about the Downstream Constraint Conflation Method

Summarize Z
The Summarize Z method computes z values for entire features or for each vertex within the input geometry. Z values can be computed as a mean, minimum, maximum, or specified constant LAS point z value for a feature or for each vertex of a feature.

Learn more about the Summarize Z method

Retaining Wall
The Retaining Wall method assigns elevations from the LIDAR surface to a bottom and top of wall lines. The bottom and top wall lines are stored in the output geometry as multi-part features where the bottom and top line are parallel to each other at a very small distance.

Learn more about the Retaining Wall method

If the "None" method is selected, then the features will be excluded from the conflation process. However, if the "Classify Points Within Buffers" flag is turned on, points can still be classified within the buffer of the input geometry.

Learn more about classifying points within buffers

Learn more about toggling the use of type values
 

How to Select a Conflation Method

1. Click within the Conflation Method column for the type value you wish to assign a conflation method.

2. Select a conflation method from the list.

3. If the selected conflation method has properties, the property page for the method will appear. Input the properties accordingly, and select OK.