Create Complex Terrain Model

Used to merge or append multiple terrain models into one.

You can access this tool from the following:

Ribbon: Terrain > Create > Additional Methods split button
Ribbon: Home > Model Import/Export > Terrain Import split button

The Create Complex Terrain Model tool is used to merge or append multiple terrain models into one. Order is important as the models are processed in the order listed. It is also crucial to specify append or merge as appropriate for the project, as the results may be dramatically different.

Any two terrain models can be merged together as long as one terrain model overlaps the other model in at least one point. A warning message is displayed if there is no overlap, and no processing occurs.

Workflow

1. Start the command.

2. All available terrain models in the active DGN and its references are listed in the panel to the left.

3. Select the base (primary) terrain on left and click Add in the middle of the dialog to add it to the merge list on the right.

4. Select additional terrain models on the left one at a time, select Merge or Append in middle and then click Add.

5. When the merge list is complete, set the feature definition to be assigned to the new terrain model.

6. Click Finish.

Changing Merge or Append Order

Settings	Description
	raise the selected surface position in the surface list.
	lower the surface position in the surface list.

Current Action Merging or Appending Terrain Models

Both merging and appending combines the data contained in multiple (two or more) models. However, they are not the same process and yield different results.

When appending, the software triangulates the combined data from the two terrain models using all data from both models and ignoring none. The two models may overlap or be adjacent to one another. If there is data in both models in a common area, it is all utilized for triangulation.

When merging, the software triangulates the combined data from the two terrain models in areas where they do not overlap. The two models must overlap at least one point. If there is data in both models in a common area (overlap), the data from the primary model is discarded, and only the data from the merging model is used. Therefore, order is critical.

In the example above, TM1 is the primary model, and TM2 is being merged (lower on the order list). In the shaded area (which both terrain models have in common), the data from TM2 is utilized, and retriangulated around the common edges. The data within the shaded area from TM1 is discarded. The hull of the new, merged terrain model is shown.