25.4. Scene Editing Mode Techniques
This section will focus on techniques to use in Scene Editing Mode. After reading this chapter, the user should have a good understanding on how to create and edit scenes in Bulldozer.
25.4.1. Open and Save Scenes
Bulldozer opens and saves scene files in DIRSIG ODB format. An ODB file does not contain actual objects, but file and scene location of every object used in the scene. As a result, Bulldozer assumes all object files are in a static location that will not change.
Open or Open Scene under File in the menu bar can be used to load in a previously saved scene. Save and Save As under File in the menu bar can be used to overwrite a previous version of the current file, or to save the scene under a new filename, respectively. (see Section 25.2.2.)
25.4.2. Create A Scene
When creating a scene, there are techniques the user can use to speed up the process. For a large scene, it is recommended that the scene is split up into sections and created section by section. The reasoning behind this is so Bulldozer will not have to load every single object in the scene, when the user only has the intentions to work on one specific section. This method also allows multiple people to work on a scene in parallel.
Splitting up a scene does not require having to physically split the base plate for the scene. Instead a new scene should be created, using the same base plate for every section of the scene. The only difference from working on the scene as a whole, and this technique is that there will be multiple DIRSIG ODB files instead of one. Each one will contain a copy of the base plate, but DIRSIG will only need to load one plate since all the files have the same exact plate at the same scene location.
First, insert the base plate and any objects needed on top of the plate in the first section to be worked on. Next, save the scene and load a new workspace. Plant the same plate again, and insert the objects in the next section. Save the scene under a different name, load a new workspace and repeat until all sections are saved. When all the ODB files are processed in DIRSIG, all the objects in the scene will be merged together and placed in their proper locations to create a final scene.
Note: See Section 25.2.3 for more information on how to insert objects in a scene.
25.4.3. Insert Objects
To insert an object into a scene, a mouse button must be set to Insert Object in the Mouse Panel (see Section 25.2.3). Next, select the object to insert from the Available Object List. Finally, click in the Viewing Pane where the object should be placed. The object will appear in the Viewing Pane at the location where the mouse was clicked. Bulldozer will automatically calculate the highest point on the terrain at the mouse click and insert the base of the object at that location. Depending on the options set in Insert Dialog under Options in the menu bar, the Insert Dialog box may appear right after the mouse click in the Viewing Pane.
25.4.3.1. Insert Dialog
The Insert Dialog gives more options specifying how an object is inserted into a scene. To turn on/off the appearance of the Insert Dialog box for every object insertion, just click on the appropriate option in Insert Dialog under Options in the menu bar. The dialog box is divided into four main parts: Location, Scale, Rotation and Identification.
Note: At the bottom of the dialog box is a check box option "Don't show this again". This option works just as Disable Insert Dialog from Insert Dialog under Options in the menu bar. This is useful when inserting a lot of objects into a scene based on the same random values.
25.4.3.1.1. Location
Location specifies where the object is located in the scene. There are two methods in which the location can be modified:
The first method, ``Specify fixed values'', accepts exact X, Y, and Z values for an object. These values are pre-filled with location values given from the initial mouse click for insertion.
The second method, ``Generate random values'', takes a range of values for each X, Y and Z coordinate. With this method, the computer will randomly pick a value for each coordinate, between the specified ranges, and insert the object at that location.
25.4.3.1.2. Scale
Scale scales the size of an object by a scale factor before inserting it into the scene. Objects are scaled along their X, Y and Z axis individually. There are two methods for specifying a scale factor:
The first method, ``Specify fixed values'', accepts exact X, Y, and Z values to scale the object by.
The second method, ``Generate random values'', takes a range of values for each X, Y, and Z scaling. With this method, the computer will randomly pick a value for each axis, between the specified ranges, and scale the object.
25.4.3.1.3. Rotation
Rotation rotates an object before inserting it into the scene. Objects can be rotated along their X, Y and Z coordinates. There are two methods available for rotating an object:
The first method, Specify fixed values, accepts the exact angle to rotate the object on the X, Y, and Z axis. Values are normally from 0 to 360.
The second method, Generate random values, takes a range of values for each coordinate to rotate on. With this method, the computer will randomly pick a value for each coordinate, between the specified ranges, and rotate the object.
25.4.3.1.4. Identification
Identification displays the name of the object to be inserted into the scene and its instance name to display in the parts list. Object Name is the name of the file containing the object. Instance name a name given to that specific instance of the object, to differ from other instances of the object. Instance Name can be modified to any naming convention the user wishes to use.
25.4.4. Viewing Angles
In Scene Editing Mode the View Selector provides angles to view the whole scene from. The different viewing angles have no effect on the actual orientation of the scene. These angles only effect the angle the scene is viewed from in the Viewing Pane. For additional viewing angles, use Rotate View and Translate View in the Mouse Panel.
25.4.4.1. Rotate & Translate View
Bulldozer provides a way to manually change the viewing angle of a scene. Using Rotate View and Translate View in the Mouse Panel simply click the Viewing Pane and drag the mouse until the desired angle is reached. While dragging, every object in the scene will change to their dynamic visualization. Afterwords, they will return to their static visualization in the new viewing angle. If there is a need to return to a normal viewing angle, it is suggested to use one of the standard viewing angles provided in the View Selector.
Note: See Section 25.4.5 for more information on static and dynamic visualizations.
25.4.5. Instance Editor
The Instance Editor contains options for modifying general attributes of a selected object. Modifications made in the editor are only applied to the currently selected instance of an object. The Instance Editor has the ability to change the instance name of an object, how it appears in the Viewing Pane and its geometry.
25.4.5.1. General
Contains options for changing basic attributes of an object in the scene.
25.4.5.1.1. Visualization
Under Visualization are options for setting parameters for displaying the object in the Viewing Pane. There are two types of visualization for an object: static and dynamic.
Static is how an object is displayed in the Viewing Pane when no major modifications are made to it. This type has three options: Box, Wireframe, and Shaded. Box displays the object as a solid six sided box. Wireframe displays an outline of every facet of the object in white. Shaded displays the object with every facet/polygon colored and shaded.
Dynamic is how to display an object while making a major modification to it, such as rotating and translating. So far the only option under this type is Box.
25.4.5.2. Geometry
Geometry specifies an object's location, scale and rotation. Under each section is a Reset button. The Reset button sets the values for each section back to their minimal value.
25.4.5.2.1. Location
To the right of Location are three text boxes that specify the object's current location along the X, Y and Z axis respectively. A different value for each axis can be specified by simply changing the values in the text boxes.
25.4.5.2.2. Scale
To the right of Scale are three text boxes for scaling along the X, Y, and Z axis, respectively. Scaling along each axis is done by entering a different scale factor in the corresponding box. The default scale factor is 1.
25.4.5.2.3. Rotation
Rotation specifies the object's rotation along the X, Y and Z coordinates respectively. The object's angle of rotation can be specified along each axis using the three text boxes available. Legal angles are between 0 and 360.
25.4.5.3. Overlay
Overlay allows an image to be wrapped around an object. This option can be used for laying an aerial image of a neighborhood over a plate as tracing paper for planting houses and trees. To insert an overlay, an overlay file must be specified in the Filename text box. There is a browse button that allows the user to browse to the specified file.
25.4.5.3.1. Origin
Specifies the X, Y and Z coordinates to begin the image overlay.
25.4.5.3.2. Scale
Scale specifies the scale factor to scale the image by, before it is overlaid.
25.4.6. Hide and Delete Objects
Objects within a scene can be hidden or deleted from the scene. Hiding an object and deleting an object are two different operations. When an objected is deleted from the scene, its name is removed from the Used Objects list and the object is removed from the Viewing Pane. That instance of the object cannot be recovered and has to be re-inserted into the scene from scratch. However, when an object is hidden it becomes invisible, and the word ``Yes" will appear next to its name in the Used Objects list under Hidden. The object can be restored to its normal state by selecting UnHide. Hiding is useful when the user needs to get a better view at an object that is blocked by another. The user can hide the obstructive object and come back at a later time to un-hide it, before saving the scene.
25.4.7. Correct Normals
After inserting an object into a scene, the user may notice that the normals on the object are reversed. To correct this problem, use Flip Normal in the Mouse Panel. Flip Normal, in Scene Editing Mode will flip all the normals on an object. The sides of an object will become lighter or darker, depending on the previous normals. To restore the original normals, use Flip Normal on the object again.