4 - Rigid Body and Surface Texture

1.0 Introduction

This tutorial will introduce the rigid body analysis method and show you how to apply a texture image to the slope surface.

Topics covered in this tutorial:

• Rigid Body Analysis Method
• Apply surface texture to the slope
• Area Seeders

Finished Product:

The finished product of this tutorial can be found in the Tutorial 04 Rigid Body and Surface Texture.r3DModel data file. All tutorial files installed with RocFall3 can be accessed by selecting File > Recent Folders > Tutorials Folder from the RocFall3 main menu. By default all tutorials and verification files are installed in the folder C:\Users\Public\Documents\Rocscience\RocFall3 Examples.

2.0 Model

2.1 Analysis Type

1. Select: Analysis > Project Settings
2. In the Methods tab, select Rigid Body from the dropdown.



3. Click OK.

2.2 Import Geometry

In this tutorial, we're going to import a provided *.obj file.

1. Select File > Import > Import Geometry or Geometry > Import/Export > Import Geometry .
2. Navigate to and open the provided Tutorial 04.obj file in the Tutorials Folder. By default, the Rocscience Installer uses the folder C:\Users\Public\Documents\Rocscience\RocFall3 Examples\Tutorials.
3. You will see the Import Geometry dialog, which displays a preview of the geometry. Select the Mesh object and click on Post-Processing.
4. In the Post-Processing step, you can simplify and repair the geometry. Click on Simplify Triangulation > Simplification Level, click on Custom and enter a triangle count of 50,000. Click OK.



5. Click on Find and Repair Defects next. Click on Repair. When there are no defects left, click Close.
   Note: If there are defects after clicking Repair, Clicking Repair again may fix these defects,
6. Click Done.



7. You will then be prompted to set the imported surface as the slope. Click Yes.

2.3 Apply texture to surface

1. Select the slope surface by clicking on it, or clicking on the Slope item in the Visibility Tree. The Geometry in the main view should turn orange.
   
   
2. Select Geometry > Assign Texture to Surface.
3. Navigate to and open the provided Tutorial 04.jpg file in the Tutorials folder.



4. You will see the Texture Image dialog, which displays a preview of the image. You can scale and move the image in this dialog to fit your geometry. For the supplied image, it has been adjusted. You can just click on OK.
   
   
   Note the warning dialog that pops up:
   
   The texture is meant to be added after any geometry changes to the underlying mesh. Often you may want to add it before looking at results. There are certain geometry operations that will delete the texture. However, features such as Repair, Simplification, and Re-Triangulation do not remove the texture. Press OK to continue.
   
5. You may notice that the Slope is still selected. Unselect the slope by either clicking in the view outside the slope geometry, or by selecting the Clear Selection option on the toolbar. You will see the texture overlay on the slope. This can be improved by adjusting the slope transparency. In the Visibility Tree, select the slope. In the Properties pane, lower the transparency by dragging the slider or entering a lower value in the edit box. You can also Add or Delete the texture image in the Textures groupbox below. In this tutorial, let's change the slope transparency to 0%. Then Clear Selection.
   

You can see the river and the highway very clearly on the slope.

2.4 Show Topographic Lines

1. Select Annotate > Topographic Lines in the menu or click on the icon in the toolbar.
2. In the Visibility Tree, ensure the Topographic Annotation is selected to view the options in the Properties pane below.
3. Go to the Properties Pane, change the Spacing to 100 and check Show Colors.

The topographic lines turn the model into a topographical map. It can serve as a visual aid to place slope-dependent elements (such as seeders and barriers).

When done turn off the display of the Topographic Annotations by clicking on the eye icon in the Visibility Tree.

2.5 Material Properties

1. Select Materials > Define Materials
2. Define the following 3 materials:
   

   Name	Normal Restitution	St. dev. / Rel.Min / Rel.Max	Dynamic Friction	St. dev. / Rel.Min / Rel.Max
   Hard	0.2 (Normal)	0.03 / 0.09 / 0.09	0.4 (Normal)	0.04 / 0.12 / 0.12
   Soft	0.1 (Normal)	0.03 / 0.09 / 0.09	0.8 (Normal)	0.04 / 0.12 / 0.12
   Water	0.0 (None)	-	0.99 (None)	-

   
   Also change the color of the water to Light Blue. Press OK when done to close the Material Properties dialog.
   
   
   

2.6 Add New Material Regions

To add the material regions:

Select the Material Regions tab (located next to the Visibility Tree) or from the menu Materials > Edit Material Regions . This is where the overlay texture image will aid us.

2.6.1 Define Water Region

1. Select the Draw New Region.
2. Select The Water Property and click OK.
3. We're now in the Draw Polyline mode for defining the polygonal region with the Water material assignment. Roughly trace around the river near the bottom of the slope.
   
   
4. If you want the same points as this model, select the Edit Table button in the Draw Polyline pane section, and then Import the following Tutorial 04 Water Region.txt file.
5. When you're done, right-click in the viewport and select Done .

2.6.2 Define Soft Region

1. Select Draw New Region.
   
2. Select the Soft material property to use and click OK.
   
3. Roughly trace around the flatter area around the river (including the highway).
4. If you want to use the same points as this model, select the Edit Table button in the Draw Polyline pane, and then Import the following Tutorial 04 Soft Region.txt file.
5. When you're done, right-click and select Done .
   

2.6.3 Reorder the regions

1. In the Defined Regions list, select Region 1 (the water region). Click on the Up arrow to move it to the top of the list.



2. Click on the Visibility Tree tab in the left pane to get out of the Material Regions definition mode.

2.7 Seeder Properties

1. Select the Seeders workflow tab.
2. Select Seeder > Define Seeder Properties in the menu. This opens up the Seeder Properties dialog.
3. Under the Rock Shapes tab, select the Edit Pencil Icon located next to shapes.
4. In the Rock Shapes dialog, select the Icosphere (32 faces), Dodecahedron and Icosahedron shapes, click Ok to close the dialog.
5. Switch to the Number of Rocks tab. For the first seeder, change the Number of Rocks to 150. We'll keep everything else the same, so the rock will be free falling from the seeder location.
   
   
6. Click on the Add button to add a new property.
   
7. For this second seeder property, repeat steps 3 and 4 above.
8. Switch to the Number of Rocks tab. Then change the Number of Rocks to 50.
   
   
9. Click OK to save and exit out of the Seeder Properties dialog.
   

2.8 Add Seeders

For this model, we'll add 1 line seeder and 1 area seeder.

2.8.1 Line Seeder 1

1. Turn on the display of the topographic lines by pressing the eye icon in the Visibility Tree.
2. Select Seeder > Add Line Seeder
3. The Add Line Seeder dialog pops up. Make sure the first seeder property with 150 rocks (Seeder Property 1) is selected for Property.
4. Select the Height Above Surface radio button. Enter 1 m.
   



5. Click on Add Points on Viewport. In the top view, try to trace along the 2100 m topographic line on the upper left corner.

If you want the same points as this model, import a polyline by selecting Geometry > Draw Polyline, and then press the Edit Table button and Import the following Tutorial 04 Line Seeder.txt file, right click and select done, click on the polyline and then navigate to Seeder > Add Line Seeder from Polyline, and press Ok.

6. When you're done, right-click and select Done .
7. Click OK to save and exit out of the Add Line Seeder dialog.

2.8.2 Area Seeder

1. Select Seeder > Add Area Seeder.
2. Ensure that Seeder property 2 is selected in property.
3. Enter 1 m as the Height Above Surface value.
   
   
   
4. Select the Add points on viewport button,
5. In the top view, try to circle an area on the upper right corner. Left Click and hold on the top right corner of the model and drag your mouse forming a circle, right click and select done.
6. Select Ok to close the Add Area Seeder dialog.
   
   
   
   

3.0 Compute

Now we're ready to compute.

• Select: Analysis > Compute

4.0 Results

With the aid of the texture overlay, we can easily see that the rocks from the South hill would stop after hitting the river, but a small portion of the rocks from the North hill would hit the highway. Protection will be required.