3.5 Viewing images in 3D

For images with 3D information Maestro can create a ThreeD (3D) view. The ThreeD view is very good for analyzing the locations and shapes of the terrain around the rover. It is also great for viewing the rover at its current position and heading with respect to its local area (see Figure 3.16). As you create an Activity plan for the rover, the ThreeD view will position the rover and turn its mast and arm to the intended position specified in each Activity. We will cover planning in more detail in Section 4.3, so for now let’s discuss how to navigate and analyze terrain with the ThreeD view.

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To open a ThreeD view, right-click (or [Ctrl]-click if you have a single-button mouse) on an image or collection in the Downlink selection tree and select “Open in ThreeDView” or “Open in OverheadView”. (The Overhead is a specific type of ThreeD view that displays terrain from a bird’s eye view).

3.5.1 Navigation

There are a number of navigation tools in available in the ThreeD view:

Orbit navigation

Orbit navigation lets you rotate around the view center to see the terrain from different points of view. This style of navigation prevents you from moving the point of view below the ground plane; it will only view the terrain and rover from above. It will also keep the view center in the view as you zoom in and out of the scene.

To change orientation:

• drag the mouse while holding the left button down, or
• use up, down, left and right cursor keys

To zoom in and out:

• drag the mouse up and down while holding the middle button down (if your mouse is single-button then drag while pressing [Alt]), or
• use the up and down cursor keys while pressing [Alt]
• Note: on a Sun workstation use the [Meta] key (with a diamond on it) in place of [Alt]

To pan from side to side or up and down:

• drag the mouse while holding the right button down (if your mouse is single-button then drag while pressing [Ctrl]), or
• use the left, right, up and down cursor keys while pressing [Ctrl]

To accelerate any motion, press the [Shift] key while moving.

Some operating systems and desktop environments may reserve some of these key/button combinations for other purposes...if you find that the controls don’t work the way they are described here, try changing your system preferences.

Spin Navigation

Spin navigation is very similar to Orbit navigation but allows you unconstrained movement about the view center. You can move the point of view under the ground plane or view the terrain from any direction. The navigation key/mouse controls are the same as those used in Orbit navigation.

Slide Navigation

Slide navigation is similar to Orbit navigation except that rotation around the view center is not available. The key/mouse controls are the same as in Orbit navigation except that left-clicking and dragging pans (slides) the scene instead of rotating it.

Overhead Mode

Overhead mode navigation shows you the terrain from a bird’s eye view. To activate Overhead mode in ThreeD view, select “Overhead mode” from the Action menu. This navigation mode is similar to Slide navigation; to pan the scene up, down left and right either click and drag the mouse while pressing the left button or use the up, down, left and right cursor keys. To zoom in and out, drag the mouse while pressing the second button (press [Alt] if using a single-button mouse), or use the up and down cursor keys while pressing [Alt].

If you open an Overhead view, this navigation is the only navigation that you can use; you cannot switch to another navigation mode in the view. To use a different navigation mode, close the view and re-open it in a ThreeD view.

Navigation disable

To freeze the ThreeD view at the current point of view temporarily, uncheck the “Navigation Enabled” checkbox menu item on the Navigation menu.

Navigation Help

To get information about navigation controls in the ThreeD view, select “Describe Navigation Controls” from the Navigation menu.

3.5.2 View center

In the last section we refer to the view center for Orbit and Spin navigation. When you open a ThreeD view, the view center is located at the site where the rover acquired the images that you see as terrain. When you rotate around in Orbit or Spin navigation, the view center is the center of the rotation. Also, when you zoom in and out of the scene, you move toward or away from the view center. The view center is shown as a translucent pink circle in the ThreeD view.

Sometimes you need to zoom in closely on a spot on the terrain that is far from the current view center. There are several tools to help you change the view center:

User defined view center

You can set the view center to any place you can see on the terrain by picking the point (click on it with the mouse) and setting a user-defined view center. After clicking with the mouse, select “User defined” from the View Center menu. This will display the User defined view center dialog (see Figure 3.17).

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Click the Create New... button to set the new view center (you may name it whatever you like or select Ok to use the default name). When you close the dialog, the view will use your new view center. You may return to this dialog and create as many view centers as you like, and switch between them as needed by highlighting the view center in the list and selecting “Set Location”.

The list down the right side of the dialog is used to define the point of view you want to have for your view center. The options are:

• Above: Look down on the view center from above
• Below: Look up on the view center from below (only in Spin navigation mode)
• Front: Look at the view center from the north
• Back: look at the view center from the south
• Right: look at the view center from the east
• Left: look at the view center from the west
• Oblique: look down at the view center from a 45 degree angle. This is how the ThreeD view first appears when opened.

These options are also available in the other view center actions.

Terrain view center

To select a view center in the middle of a particular terrain wedge (segment), Select Terrain... from the View Center menu and select the ID of the terrain to set as the view center. (Terrain IDs are displayable via the Display-¿All Terrain-¿Labels-¿Show All menu item.)

Site-relative

You can select a Site as the view center by selecting a site from the View Center-¿Sites menu.

Global

To capture the entire scene in the ThreeD view you set the view center with the View Center-¿Global menu item. This will set the view center and zoom out so that the entire scene is visible in the view.

View center reset

To reset the view center to the initial settings, select the Reset to View Center Default menu item from the Navigation menu.

View center visibility

To show or hide the view center (it looks like a pink translucent circle), check or uncheck the Show View Center checkbox menu item on the Navigation menu.

3.5.3 Terrain appearance

The level of detail (how detailed the shape of the terrain and the color appears) is managed automatically in ThreeD view depending on how far your navigation “eye” is from the scene. The ThreeD view also has a number of tools to adjust the appearance of the terrain:

Wireframe terrain

You can turn off the terrain texture (the images that are overlaid on the scene) and view the scene in wireframe as sort of a line drawing. To view the scene in wireframe, select Set All to Wireframe in the Display-¿All Terrain-¿Render Mode menu.

Textured terrain

To view the scene with images overlaid on the scene (as it appears when the view is opened), select Set All to Textured in the Display-¿All Terrain-¿Render Mode menu.

Terrain labels

It is sometimes useful to see the ID labels of each terrain wedge in the view, for setting a view center or correlating a terrain with an image in a Mosaic view. To view the terrain ID labels for each terrain wedge, select Show All from the Display-¿All Terrain-¿Labels menu.

Terrain bounding boxes

You can view rectangular box that surrounds each terrain wedge by selecting Show All from the Display-¿All Terrain-¿Bounding Boxes menu.

Terrain Level of detail

You can select the level of detail of the terrain geometry by selecting the following options from the Display-¿All Terrain-¿Geometric LOD menu:

Texture Level of detail

You can select the detail of the textures (images overlaid on the terrain) by selecting the following options from the Display-¿All Terrain-¿Texture Resolution menu:

Picking a Point of interest

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You can click on any point on the terrain in the ThreeD view to get more information about that point (see Figure 3.18). The Point of interest looks like an exclamation point with the point placed at the selected position. The cone of the Point of interest points in the direction normal to the underlying surface. (A perfectly level surface would have a Point of interest pointing straight up, where a sloped surface would show a similarly sloped Point of interest.)

Downlink info pane

The ThreeD view provides information about the rover’s position where the images in the scene were taken and about the selected point. (See Section 3.3.3 for more details on the selected position.) It also gives you details about the currently selected terrain wedge:

• Current Level of detail
• Level of detail mode (high, low, auto, or quad)
• Number of vertices and triangles in the current geometry
• Number of textures used on the current geometry
• Render mode (wireframe or textured)
• Texture version
• Texture resolution (width and height in pixels)

Disabling picking

Sometimes if you have selected a Point of interest it is useful to switch off picking as you navigate around to view it from different angles. To temporarily switch picking on or off, check or uncheck the Picking Enabled checkbox menu item in the Navigation menu.

Ruler

The Ruler tool lets you select two points on the terrain and measure the distance between them. To use the Ruler tool, select the Ruler menu item on the Action menu or the toolbar. To measure between two points, click and drag while pressing the left button from one point on the terrain to another. As you drag the mouse, the ruler will appear as a yellow line that follows your mouse as you move to the second point. When you release the mouse, the ruler will remain in place. The Downlink info pane will tell you the positions of the two ruler endpoints and the distance between them.

In Ruler mode you cannot navigate around in the scene. To restore navigation, select the Pick and Navigate menu item on the Action menu or the toolbar.

Open selected wedge

If you are viewing a scene that has a collection of terrain wedges, you can open a new ThreeD view with just the currently selected wedge in it. To open the selected wedge in its own ThreeD view, make sure you have clicked on the wedge you want to view and select the Open Selected Wedge menu item in the Action menu.

If your browser only has one view pane, opening a new ThreeD view from the current ThreeD view will replace the current view. To avoid this, configure your browser for multiple view panes (see Section 3.2).

Site axis display

The ThreeD view displays a site reference frame in the scene for reference. The site frame is positioned at the site where the rover was when the images were captured. The site axis display points north, east, and down with respect to the site. You can show or hide the site axis display by checking or unchecking the site axis checkbox menu item on the Display menu.