Exercise 9: Creating a realistic 3D view

Complexity: Intermediate Data Requirement: Installed with software Data Path: See Copying the tutorial data Goal: Use 3D symbology and 3D graphics tools to transform 2D feature datasets into realistic looking 3D data models

Imagine that you are an urban planner and are interested in constructing a realistic 3D model of a neighborhood. The staff of the planning and transportation departments has created GIS datasets for the building footprints, streetlights, trees, and sample vehicles for this area. You also have imagery of the area, and an architect has supplied a set of photorealistic building models.

You want to combine the GIS data with the image and the building models in ArcGlobe to develop a realistic urban model. This model will help decision makers visualize proposed buildings and their associated views. Such models can also be used to study spatial awareness or to simulate urban features, landscapes, landmarks, or tourist attractions for students or tourists.

This is an advanced exercise illustrating how to use 3D symbology and 3D graphics tools to create a realistic-looking view of a study area in London.

Opening the London Globe document

Steps:

1. Start ArcGlobe by clicking Start > All Programs > ArcGIS > ArcGlobe 10.
2. On the ArcGlobe - Getting Started dialog box, click Browse and set the globe's default geodatabase path to D:\3DAnalyst\3D_Default.gdb
This location will be used for output spatial data generated in the tutorial exercises.
3. Next, on the ArcGlobe - Getting Started dialog box, click Existing Scenes > Browse for more .

The Open dialog box appears.
4. Navigate to the Exercise9 folder.
5. Double-click the London_Start ArcGlobe document.

The ArcGlobe document contains high-resolution images (courtesy of DigitalGlobe QuickBird), one 3D feature dataset symbolized with tree symbols, and one 3D textured multipatch dataset representing the buildings in the study area.

6. Click File and click Save As.

7. Type London for the name of the globe document.

8. Click Save.

Setting the visible distance range of a layer

You can optimize the performance of an ArcGlobe document by setting an appropriate visibility distance for each layer. Specifying the visibility distance range lets you control when a layer becomes visible as you zoom in or out. You can either set the minimum and maximum distance for an entire layer, or you can base the layer visibility on individual tile distances.

The checked box beside the Buildings layer is unavailable in the table of contents. This means the display currently exceeds the layer's maximum visibility distance. You will change the maximum visibility distance for a couple of other layers later in this exercise.

Steps:

1. In the table of contents, right-click the Holborn.jp2 layer and click Properties.

2. Click the Globe General tab.
3. Click the Don't show layer when zoomed option.

4. Type 5 in the Out beyond text box.
The units used for this distance are kilometers.
5. Check visibility based on each tile distance to enable distance visibility for discrete parts of the layer.
This setting, although not enabled by default, further improves performance. When enabled, discrete tiles of data appear visible when navigating near their layer's distance threshold.
6. Click OK.
The layer will be visible between the minimum and maximum distance.
7. Click Bookmarks and click City View.

The display is now repositioned to the City View bookmark. All the datasets are now visible, because you are within the visibility distance range of all layers at this scale.

A layer's visibility range can also be set according to current display distances. Right-click a layer in the table of contents, point to Visible distance range, then use the Set Maximum Distance and Set Minimum Distance commands to capture display distances.

Tips on allocating memory cache

Often, an ArcGlobe document that is performing poorly can be made interactive through a well-defined memory cache. This is a specified amount of physical memory (RAM) dedicated for exclusive use by ArcGlobe to improve performance. For optimum performance, the memory cache can be fine-tuned according to the individual data types used. As this exercise uses many 3D textured objects and raster images, your next step will be to allocate a greater percentage of the memory cache to improve handling of these data types.

Steps:

1. Click the Customize menu and click ArcGlobe Options.

2. Click the Display Cache tab.
3. Click the Advanced button.

4. Take a glance for the memory allocation values, in megabytes, and types.
Each data type's current memory usage as an absolute value and as a percentage of its allocated size is detailed in the text box and horizontal graph to the right of each item.
The total memory cache size is calculated as the sum of the individual data type settings. This total cannot exceed the amount of physical memory (RAM) installed on your machine.

If necessary, click the Balance Current Usage button to prevent the size of the memory cache from exceeding your available physical memory (RAM).
The Balance Current Usage button will automatically balance the allocation of memory used for each data type, based on the current memory usage of the document.
If you allocate a small amount of physical memory (RAM) to a particular data type and subsequently create a document that makes extensive use of this data type, it will start paging the data to disk well before physical memory is exhausted, leading to reduced performance.
You will utilize this tool after you have fully authored the 3D view and have interacted within it for a while to ensure that the memory allocation applied best represents the kinds of data you have in the document.
5. Click OK to close the Advanced Memory Cache Settings dialog box.
6. Click OK to close the Options dialog box.

Adding feature data

To create 3D objects on your model, you will add some local data to the London area.

Steps:

1. Click the Add Data button.

2. Navigate to the location of the Exercise9 tutorial data folder.
3. Open the Geodatabase folder and double-click the Lincolns.gdb geodatabase file.
4. Holding down the CTRL key, click the Building_Footprints, Street_Lights, and Vehicles feature classes.
Holding down the CTRL key lets you select multiple items.

5. Click Add.
A sequence of three Add Data Wizards will appear for each feature layer beginning with Building_Footprints.
6. Click Don't show layer when zoomed to apply the distance visibility range.
7. Type 3 in the out beyond text box, and leave the in beyond text box set to the default value of 0.

8. Click Finish.
9. Click Display features as 3D vectors when the Add Data Wizard appears for Street_Lights layer.

10. Click Next.
11. Click Don't show layer when zoomed to apply the distance visibility range. Then type 1 and 0 in the distance range text boxes.

12. Click Next.
13. Select the typical scale at which this layer will be seen in real-world units.

14. Click Finish.
15. Repeat steps 9 through 14 for the Vehicles layer.
If prompted, close the Geographic Coordinate Systems Warning message box. The data will be projected to the ArcGlobe program's currently set Geographic Coordinate Systems.

16. Click Bookmarks and click Bird View.
Now you can see all the layers you have added to the study area. The table of contents indicates that these feature layers have been added as draped layers in the 3D view.

Extruding buildings

Features in a two-dimensional data source can be projected into a three-dimensional representation through a process known as extrusion. A 2D building footprint, for example, can be extruded into a 3D block representation of that building. In this exercise, you will extrude building polygons according to a height value governed by the number of floors and average height per floor to create realistic 3D building shapes.

Steps:

1. In the table of contents, right-click Building_Footprints layer and click Properties.

2. Click the Globe Extrusion tab.
3. Check Extrude features in layer.
4. Click the Calculate Extrusion Expression button to open the Expression Builder dialog box.

5. Click the attribute NUM_FLOORS to add it to the Expression text box.
6. Assuming that each floor has a height of 4 meters, you can calculate the height of each building by multiplying the number of floors in each building by 4.
Set the expression to [NUM_FLOORS] * 4 to reflect the following graphic.

7. Click OK.
8. Click OK to close the Layer Properties dialog box.
The 2D building footprint features are now extruded into 3D blocks.
Optionally, to increase performance, you can choose not to draw the bottom faces of extruded polygons.
Navigate around the display to view your results.

Symbolizing features

Steps:

1. In the table of contents, right-click the Street_Lights layer and click Properties.
You can also open the Layer Properties dialog box by double-clicking the layer.
2. Click the Symbology tab.
3. Click Categories.
ArcGlobe automatically selects the Unique values option.
4. Click the Value Field drop-down arrow and click MODEL.
5. Click Add All Values.
This adds all unique values to the list. You could also have clicked the Add Values button to choose specific Model values to display.

6. Double-click the symbol for stlght13.

7. In the Symbol Selector dialog box, click the Style References.

8. In the Style References dialog box, check 3D Buildings, 3D Street Furniture, and 3D Vehicles then click OK.
Styles are a collection of symbols, colors, map elements, and other graphical elements stored in a library to use inside ArcGIS.

9. In the Symbol Selector dialog box, click inside the Search combo box and type street light, then press Enter.
10. Click the Street Light 13 symbol.
11. Type 8 in Size text box.

12. Click OK.
13. Double-click the symbol for stlght7.

14. Repeat steps 9 through 12, except type 5 for the size, and assign Street Light 7, or another street light symbol you prefer.
15. In the Layer Properties dialog box, click the Advanced button and click Rotation.

16. Click the Rotate Points by Angle in this field drop-down list and click Angle.

17. Click OK.
18. Click OK on the Layer Properties dialog box.
19. In the table of contents, double-click the Trees layer.
Make sure the Symbology tab is selected.
20. In the Layer Properties dialog box, click the Advanced button and click Rotation.
21. Click the Rotate Points by Angle in this field drop-down list and click random.

22. Click OK.
23. In the Layer Properties dialog box, click the Advanced button and click Size.

24. Click the Size Points by Value in this field drop-down list and click random.

25. Type 6 in the Minimum box and 15 in the Maximum box.
26. Click OK.
27. Click OK on the Layer Properties dialog box when you have finished.
The random values of rotation and size will be generated between the minimum and maximum random values specified for the trees.

Matching symbols in a style

The symbols in a style have names. If your features have values that match these names, you can automatically associate a particular symbol with each matching feature. If your features use a different set of names, you can edit the names in the style to match them.

Steps:

1. In the table of contents, right-click the Vehicles layer and click Open Attribute Table.
In the Table window, notice the Model column. Each vehicle type listed corresponds to a symbol with the same name.

2. Close the Table window.
3. Double-click the Vehicles layer to open the Layer Properties dialog box.
4. Click the Symbology tab.
5. Under Categories, click Match to symbols in a style.
6. Click the Value Field drop-down arrow and choose MODEL.
7. Click the Match to symbols in Style drop-down list and choose 3D Vehicles.style.

You can also click Browse to navigate to the 3D Vehicles.style file in the C:\Program Files\ArcGIS\Desktop10.0\Styles folder and click Open. Match to symbols in Style will now be populated with this style file.

8. Click Match Symbols.
This adds all unique values that have a matching symbol in the style.
Alternatively, by clicking Add Values, you can manually specify which unique values to display. You can also manually edit a label if you would like more descriptive labels to appear in the legend and the table of contents. This does not change the name in the attribute table.
9. Click the Advanced button and click Rotation.
10. Click the Rotate Points by Angle in this field drop-down list and click Angle.
11. Click OK.
12. Click OK again to close the Layer Properties dialog box.
Navigate around the neighborhood to view the results.

Using the graphic tools

Sometimes you need to show something that isn't represented among your GIS features. You can add graphics to ArcGlobe and display them with the same realistic symbols that you use for features. You can digitize 3D graphics to represent points of interest, lines to delineate boundaries or roads, polygons that fill an open area, or text to name or describe places. To do so, you need to add the Globe 3D Graphics toolbar.

Steps:

1. Click Customize, point to Toolbars, and select Globe 3D Graphics.

The Globe 3D Graphics toolbar appears.

2. If you want to dock the toolbar along with other toolbars, simply drag it to the desired location.

You can also add/remove toolbars by right-clicking on a toolbar or in the gray area where toolbars appear. This opens the toolbar list. The visible toolbars are checked.

Creating a graphic layer

You can control the visibility of graphics by storing them in a named graphics layer. The graphics layer will be listed in the ArcGlobe table of contents, where you can turn it on and off like other layers.

Steps:

1. Click Bookmarks and click City Hall.
2. On the Globe 3D Graphics toolbar, click Graphics and click New Graphics Layer.

The New Graphics Layer is added to the table of contents under Draped layers.
3. Double-click the New Graphics Layer to open the Layer Properties dialog box.
4. Type My Buildings in the Layer Name text box.

5. Check Don't show layer when zoomed.
6. Type 3 in the out beyond text box.
7. Click OK.

Setting the target layer and digitizing a 3D point graphic

Steps:

1. On the 3D Graphics toolbar, click the Graphics menu, point to Active Graphics Layer Target, and make sure the My Buildings layer is selected.

All new graphics will be added to this layer.
2. Click the Graphics drop-down menu and click Default Element Properties.

3. Click the Marker button.

The Default Marker Element Properties dialog box opens.
4. Click the Effects tab.
5. Uncheck Fixed screen size.

The fixed screen size option will not scale vector point graphic elements when you zoom in and out. It is unchecked here so the point graphic element will stay the same size in relation to the globe as you zoom in and out.
6. Click OK.
7. Click OK to close the Default Element Properties dialog box.
8. On the Globe 3D Graphics toolbar, click the New Marker tool.

3D point graphics can be symbolized with 3D marker symbols. You can choose these symbols from existing styles. This is an easy way to add realistic objects to your 3D model without editing your GIS features. Now you will add a 3D symbol for the city hall in London.
9. Add a point as highlighted in the following graphic.

A point graphic is drawn at the location you digitized.
10. Click the Select Graphics tool.
11. Right-click the point and click Properties.
12. On the Symbol tab, click Change Symbol.

13. In the Symbol Selector dialog box, click inside the Search combo box and type city hall, then press Enter.
14. Click the City Hall 1 symbol, and type 25 in the Angle box.

15. Click Edit Symbol.
16. In the Symbol Property Editor, make sure that the 3D Marker tab is selected.
17. Uncheck Keep aspect ratio to allow the dimensions of the 3D symbol to be freely adjusted.
18. Under Dimensions, type 70 in the text box for Depth (Y).

The dimension of the cityHall1 symbol is modified in the 3D Preview window.
19. Click the 3D Placement tab.
20. Type 3 for the X offset, and -5 for the Y offset.

The 3D symbol is offset in the x,y plane depending on the values supplied for x- and y-values.
21. Click OK.
22. Click OK to close the Symbol Selector dialog box.
23. Click OK to close the Properties dialog box.
24. Unselect the city hall symbol and navigate around the display to view the result.
To unselect a graphic, use the Select Graphics tool and click away from the symbol. Or, click the Clear Selected Features button.

Digitizing text graphics

Once you have added the city hall symbol to the scene, you may find it useful to add a text annotation in the same view. The text graphic element allows one to digitize 2D or 3D text in the scene.

Steps:

1. Click Bookmarks and click City Hall.
Zoom in to the roof of City Hall.
2. On the 3D Graphics toolbar, click the Graphics menu and click Default Element Properties.
3. Click the Text button.
The Default Text Element Properties dialog box opens.

4. Click the Text tab.

5. Click the Change Symbol button to open the Symbol Selector dialog box.
6. Click on Color drop-down arrow and choose Solar Yellow color from style palette.

The mouse tip displays the color name in the style palette.
7. Click OK to close the Symbol Selector dialog box.
8. Click the Effects tab on the Default Text Element Properties dialog box.
9. Uncheck Pin to surface.

Pin to surface is useful if you want to fix the text graphic to the underlying globe surface. In this case, we want to digitize the text on the roof of the City Hall.
10. Click OK to close the Default Text Element Properties dialog box.
11. Click OK to close the Default Element Properties dialog box.
12. On the 3D Graphics toolbar, click the New Text tool.

13. Click on the roof of city hall graphic.
14. Type City Hall in the text box and press Enter.

15. Unselect the text element and navigate around the display.
The text appears at the location you clicked.

Adding and modifying a 3D graphics layer

Steps:

1. Click the Add Data button.
2. Browse to the Exercise9\GeoDatabase folder.
3. Double-click the Street Objects layer to add it to ArcGlobe.

4. Click Bookmarks and click Street View.
5. On the Globe 3D Graphics toolbar, click the Graphics menu, point to Active Graphics Layer Target, then click Street Objects Layer.

6. Click the Graphics menu and click Default Element Properties.
7. Click the Marker button.
8. On the Symbol tab, click Change Symbol.
9. In the Symbol Selector dialog box, click inside the Search combo box and type traffic cone, then press ENTER.

10. Click the Traffic Cone 1 symbol.
11. Click OK.
12. Click OK to close the Default Marker Element Properties dialog box.
13. Click OK to close the Default Element Properties dialog box.
14. On the 3D Graphics toolbar, click New Marker.
15. Click three times to add three markers in front of the first 3 cars as shown here.

16. Right-click the Street Objects Layer in the table of contents and click Save As Layer File.

17. Navigate to Exercise9\GeoDatabase, select the Street Objects layer file, and click Save.

Click Yes if prompted to overwrite the existing file. The new markers you created are stored in the Street Objects layer.

Final view

You have successfully created a realistic 3D view of a small area within London. You can use one of the many navigation tools available, such as navigate, pan, and zoom, to browse the scene. You can also use the fly tool to fly over your city model.

Balance the memory cache for final view

Steps:

1. Click the Customize menu and click ArcGlobe Options.
2. Click the Display Cache tab.
3. Click the Advanced button.
Take a glance for each type of the memory values in megabytes. You will see that the memory cache size of 3D Objects (texture) is exceeding its limit.

4. Click the Balance Current Usage button.

The total amount of memory assigned to ArcGlobe is redistributed (using the current percentage-of-use per memory type), allowing very quick optimization of the memory settings for the current document.
A minimum amount of 10 MB of memory is guaranteed for each type. Saving the ArcGlobe document will ensure these optimized memory settings are honored whenever the document is opened in the future.

In this exercise, you learned how to transform 2D feature datasets into realistic-looking 3D data models. This exercise also focused on accessing symbol libraries for styles to match layer attributes. You can quickly personalize your scene with several symbol property options.

Finally, the 3D graphics toolbar is a host of many tools necessary to create and edit new 3D graphics layers and features. You are well on your way to adding realism to your 3D scene by using 3D graphics tools and symbology options available within ArcGlobe.