Week 4 Challenge

1. Create a terrain model by different methods –

1. By Graphical Filter
2. By text interpolation
3. By elements

Aim: To Create a Terrain model by different methods

Introduction:

Digital Terrain Models (DTM) sometimes called Digital Elevation Models (DEM) is a topographic model of the bare Earth that can be manipulated by computer programs. The data files contain the elevation data of the terrain in a digital format which relates to a rectangular grid. Vegetation, buildings, and other cultural features are removed digitally - leaving just the underlying terrain.DTMs are used especially in civil engineering, geodesy & surveying, geophysics, geography, and remote sensing.

In OpenRoads, a Terrain Model is created to represent the existing surface. If the source MX Triangulation is not a continuous surface and voids exist between groups of associated triangles, then importing the triangles will yield an inaccurate Terrain model. Therefore, the Terrain must be generated from the original surveyed strings that reside in the MX TOPO model.

Procedure:

By Graphical Filter

Step 1: Opening File

Open a New file with a 3D seed file

Set name as Terrain by Graphical filter and click save to open file

Step 2: Attaching Survey data

In-Home tab click on Attach tools and click on references

Click on Attach and select '3D_Survey Graphics file

Set attachment method as interactive

Click open and set the details as follows

Click ok and click fit view to view the file

Step 3: Using Graphical Filter

Go to the Terrain tab and click on From graphical filter

• Click on Terrain Filter manager
• Add New filter groups and filters as follows
• Name filters as Spots and brake lines
• Set Feature according and add levels of spots and Levels accordingly as follows

• Click finish
• Add spots filter to the terrain filter group

• Click finish

go to Graphical filter

• Select the filter group created
• Set Edge method as 'Remove Slivers"
• Set Feature Definition as Existing triangles

By Text interpolation

Step 1: Opening File

Open a New file with a 3D seed file

Set name as Terrain by text interpolation and click save to open file

Step 2: Attaching Survey data

In-Home tab click on Attach tools and click on references

Click on Attach and select '3D_Survey Graphics file

Set attachment method as interactive

Click open and set the details as follows

Click ok and click fit view to view the file

Step 3: Creating terrain

Go to the Terrain tab and click on Terrain by Additional Method

In that click Create Terrain model by Text interpolation

• Click on Terrain Filter Manager
• Create Text Filter using elements type as text
• Create Lines filter using element type line string

• Create filter group using only Lines filter created above
• Set all the parameters in the popup box
• Set edge method as Remove Slivers
• Feature definition as Existing Triangles

• Left-click to complete the process

From Elements

Step 1: Opening File

Open a New file with a 3D seed file

Set name as Terrain from elements and click save to open file

Step 2: Attaching Survey data

In-Home tab click on Attach tools and click on references

Click on Attach and select '3D_Survey Graphics file

Set attachment method as interactive

Click open and set the details as follows

Click ok and click fit view to view the file

Step 3: Terrain from elements

Click on Terrain From Elements

• Set feature type as Spot
• Set edge method as remove slivers
• Feature Definition as Existing Triangles

Go to the Home tab and click o Level display

• Click on the reference file
• Do Right-click and click on "ALL OFF"
• Select Layer 38 which is spots

Go to Element selection by layer and click on Line to select all spots

• We can see 18281 spots got selected
• Right-click to reset

The resulting Triangles are as follows

Result:

The resulting Terrain models created are as follows

1. By Graphical Filter

2. By text interpolation

3. By elements

2. Edit the terrain model created

Aim: To Edit the TIN Network

Introduction:

Editing is terrain model is to remove the spots which are at unusual elevations which create unnecessary triangles and surfaces

Procedure:

Step 1: Open Terrain Model

Create a new dgn file using the '3D seed imperial' seed file

Set name as terrain editing

Open the Reference toolbar and attach the terrain from graphics elements created earlier

Click open and click fit view

Set overrides as yes

Step 2: Editing Terrain Model

Go to the Terrain tab click on edit terrain

Use various options and delete unwanted spots and triangle

1. Remove spot

Hover over the spot until a white spot is visible and click to delete

2. Delete Edge triangles

Hover over the unwanted edge triangle to delete them as follows

click to delete the triangle

3. Swap triangle side

Select the triangle side to swap

4. Add Vertex

Hover over the area where a new vertex is needed and select the spot

5. Move Vertex can be used to move the vertex

6. Delete triangle line is used to delete the unwanted lines of terrain created using a line drawn a specific direction

Result:

After removing all the unwanted spot and triangles the Terrain model is as follows

3. Annotate the contours with labels

Aim: To Annotate the contours with labels

Introduction:

Contours can be labeled along a given line in Open roads using " Labeling Terrain contours" in Terrain Tab

Procedure:

Step 1: Open Terrain Model

Open the edited terrain model created above

Step 2: Labeling Contours

Go to the terrain tab and click on Labeling terrain Contours

Set the following settings

• Select the terrain model
• Annotation mode as All Contours
• Text Alignment as Follow Line
• Style as "Label Pln Alignment Name"

Zoom in the terrain view and label the contour

Result:

The labeling of both major and minor contours is as follows

4. Change the contour interval.

Aim: To change the contour interval

Introduction:

Contour interval can be changed in properties tab

Procedure:

Step 1: Open Terrain Model

Open the edited terrain model created above

Step 2: Change Contour interval:

Click the terrain model and hover to view properties of the terrain

• Click on properties
• Click on Terrian ET
• Select the Calculated Features
• Click on contours

• Change the contour Intervals major as 20' and minor as 5'

Result:

The resulting view of the terrain model before and after increasing contour intervals is