Creating a surface using different data selection methods

When creating a surface it is important to be aware of what data is included in the selection process.

An example of this would be selecting data that is on different layers and different elevations as shown below: 

When a surface is created with data with significant elevation differences you will see that the surface is trying to include both data sets and you’ll see results similar to this: 

The issue in this drawing is that the text had incorrect elevation which was then included in the surface. 

There are multiple methods to determine which data is selected to build a surface, to prevent scenarios like this.

Filter by Z

In MsModeling | Configuration Settings | Data Extraction | you have the option to “Filter by Z.” This option is on by default. This option determines the range of data that will be included in the surface creation. Any entities with an elevation less than 2 units will be ignored and will not be included within the surface. An example would be to give all text layers an elevation of 0 units. This would then exclude any text/descriptions from being included in the surface. The Z Range can be edited to suit the requirements of the user. 

 

Filter by Entity

In MsModeling | Configuration Settings | Data Extraction | you have the option to “Filter by Entity”

Following the selection of this filter. Return to MsModelling | Extract to Surface |You will be prompted to select your DTM surface and then will see a dialog box which will prompt you to choose the entities you want to filter. Select the entities and confirm by clicking on “Select”.

Once you have confirmed your selected entities that you want to use to filter for your surface, select OK. Your surface will be created and you will be able to create your TIN.

Select from Side View

Using either the View Cube or holding down shift and your mouse wheel, you’ll be able to view your data from a side view. This will allow you to select only the entities needed to build your surface.

 

This method allows you to visually isolate the entities you require in your surface without hiding the other data. Once the surface has been generated, a TIN and Contours can be created using only 3D entities at the correct elevation.

Isolating Layers

Isolate layers so that only the entities you wish to use to create a surface are visible.

In the MsTools Ribbon | Layer Control | The Isolate Icon can be used to select which layer of data is visible and included when creating a surface. As shown below, the MSPOINT layer has been isolated from the rest of the drawings entities.

Following the selection of layers you wish to isolate, if there is still a combination of 2D and 3D entities selected, it is possible to deselect them manually: Use the Isolation Icon, before pressing Enter: hold down the shift key and click on the entities you would like to remove from the selection.

In MsModeling | Extract to Surface | The entire area can be selected, knowing that entities which are not visible will not be included in the selection process. Selecting MsModelling | TIN | will then create a TIN to represent the newly created surface.