3D navigation

The Scene window and 3D Single Targets graph are 3D environments and have different navigation controls to echograms.

This page covers:

• Navigating in 3D space
• Navigation shortcuts
• Configuring 3D Navigation settings

Note also, that scenes model time as well as 3D space, and objects can fade in or out of view suddenly or gradually depending upon the scene time window and object valid times. See About scene animation. You can also record or automate sequences of navigational commands to play back a scene like a movie. See Movies for further information.

Navigating in 3D space

You navigate in 3D space by:

• clicking the left mouse button and dragging the mouse pointer, or

• pressing arrow keys and using keyboard shortcuts

All movements in 3D space are from the perspective of the viewer not the viewed object, i.e. it is as if you were moving through the scene holding a camera. It is always the viewer which moves never the objects in the scene.

You can record any sequence of movements and replay them as a movie.

The three possible modes of navigation are described in the table below. Each mode uses a distinct cursor to remind you of the mode you are in.

Mode	Description
Move	The camera moves in straight lines, left-right, up-down, in-out or combinations thereof. Objects and surfaces all remain fixed in space, and you move relative to them.
Rotate	A center of rotation is defined (at which the camera is looking), and three axes through this center – an up-down, a left-right and an in-out axis. The camera moves in a circle around one (or more) of these axes always looking at the center of rotation.
Pan	Three axes are defined through the camera – an up-down, a left-right and an in-out axis. The camera turns on the spot about one (or more) of these axes. The camera in effect looks in another direction from the same spot.

Move

To choose Move mode either:

• click Move in the bottom left corner of the scene, or

• press the 1 key

Three axes of motion are considered — an up-down, a left-right and an in-out axis. The camera can be moved parallel to any of these three axes as follows:

Axis of movement	Navigation action and description
up-down	Drag the mouse up or down - OR - Use the Up Arrow or Down Arrow keys Result: The camera moves in space parallel to the up-down axis.
left-right	Drag the mouse left or right - OR - Use the Left Arrow or Right Arrow keys Result: The camera moves in space parallel to the left-right axis.
in-out	Hold the Shift key and drag the mouse up or down - OR - Press the S (in) and W (out) keys Result: The camera moves in space parallel to the in-out axis, as does the center of rotation. Rotate the mouse wheel Result: The camera moves in space parallel to the in-out axis, while maintaining the center of rotation location. Note: In-out movements are not the same as zooming. It is not possible in Echoview to zoom on scenes. To zoom is to leave the camera in place and adjust the magnification of the view. To move in or out is to move the camera in space which appears to adjust the magnification of view (closer objects appear larger). The difference is significant only when considering subsequent navigation, especially rotation (in which the distance of the camera from the center of rotation is relevant).

Note: Dragging the mouse diagonally will have a compound effect of the component up-down and left-right motions expected.

Rotate

All rotation is performed about a center of rotation, a point in space, through which three axes are considered to run – an up-down, a left-right and an in-out axis. The camera moves in a circle around one (or more) of these axes always looking at the center of rotation. The position of the camera in space with respect to the center of rotation is of relevance (it defines the radius of rotation) and is the product of any earlier movements (moves or rotates).

To set the center of rotation (the point in the window around which you wish to rotate), either:

• double-click on the new center of rotation, or

• point to the new center of rotation and on the Shortcut menu (right-click), click Set center object

Note: Echoview actually chooses a point in 3 dimensional space about which to center subsequent rotations. You have selected a point in the 2 dimensional space of the screen. Echoview defines as a center of rotation the first point of intersection between a ray drawn from this point, into the screen (that is, along the in-out axis) and an object or surface in the view. The distance between the camera and this point will define the radius of rotation.

To choose Rotate mode either:

• click Rotate in the bottom left corner, or

• press the 2 key

Three axes are considered to run through the center of rotation — an up-down, a left-right and an in-out axis. The camera can be rotated about any of these three axes as follows:

Axis of rotation	Navigation action and description
up-down	Drag the mouse up or down - OR - Press the Up Arrow or Down Arrow keys Result: The camera moves in space around the center of rotation in an arc swept about the up-down axis. Note: The up-down axis rotation is conserved regardless of the status of the SHIFT key allowing fluid rotation in either direction (up or down) while the camera rotates on the spot (see in-out below)
left-right	Drag the mouse left or right - OR - Press the Left Arrow or Right Arrow keys Result: The camera moves in space around the center of rotation in an arc swept about the left-right axis.
in-out	Hold the Shift key and drag left or right - OR - Press (Shift + Left Arrow) or  (Shift + Right Arrow) Result: The camera does not move in space but rotates in place about its lens axis. This is effectively a pan. Press the S (in) and W (out) keys Result: The camera moves in space parallel to the in-out axis, as does the center of rotation. Rotate the mouse wheel Result: The camera moves in space parallel to the in-out axis, while maintaining the center of rotation location.

Note: Dragging the mouse diagonally will have a compound effect of the component up-down and left-right motions expected.

Pan

To choose Pan mode either:

• click Pan in the bottom left corner, or

• press the 3 key

Three axes are considered to run through the camera — an up-down, a left-right and an in-out axis. It is not possible to pan about the in-out axis, however, rotation about this axis is effectively a pan. The camera can be turned about the up-down and left-right axes as follows:

Axis of panning	Navigation action and description
up-down	Drag the mouse up or down - OR - Press the Up Arrow or Down Arrow keys Result: The camera pans to the up or down, it does not move in space, only the direction of view changes.
left-right	Drag the mouse left or right - OR - Press the Left Arrow or Right Arrow keys Result: The camera pans left or right, it does not move in space, only the direction of view changes.
in-out	Press the S (in) and W (out) keys Result: The camera moves in space parallel to the in-out axis, as does the center of rotation. Rotate the mouse wheel Result: The camera moves in space parallel to the in-out axis, while maintaining the center of rotation location.

Note: Dragging the mouse diagonally will have a compound effect of the component up-down and left-right motions expected.

Navigation shortcuts

Commands on the Scene window shortcut menu can be used to facilitate navigation in 3D space.

The locator in the top left hand corner of the window is also a useful orientation tool.

Configuring 3D navigation settings

Altering mouse sensitivity

3 dimensional graphics demand powerful graphics performance and can render at very different speeds on different models of graphics card. Echoview incorporates intelligent fine turning to detectable graphics card properties. Echoview also provides a means for adjusting the sensitivity of camera motion to mouse movements. These sensitivities are found on the 3D Preferences page of the Echoview Configuration dialog box.

Reversing the sense of navigation

Echoview uses "camera motion" as a model for 3 dimensional navigation. That is, the scene and all its contents are fixed in space, and the camera (observer) is moved through space and oriented to generate the desired point of view. Another common model for 3 dimensional navigation fixes the observer in space, and moves the scene (and all its contents) around the observer. The two models produce similar but opposite effects as outlined below:

Model	Drag left	Drag right
Fixed scene, moving observer	Objects move to the right on the screen	Objects move to the left on the screen
Fixed observer, moving scene	Objects move to the left on the screen	Objects move to the right on the screen

Software, such as Echoview, which works with full scenes, where objects can be in front of, behind and around the observer typically use the "Fixed scene, moving observer" navigation model.

Software which works with a single object at a time, often use the "Fixed observer, moving scene" navigation model.

The change from one navigation model to the other, similar to the change in driving on the right or left side of the road, can be initially disorienting. For those more accustomed to the "Fixed observer, moving scene" navigation model, Echoview provides a "reversal" option.

To reverse the apparent sense of motion:

1. On the File menu, click Configuration.

2. Click the Preferences tab.

3. Select the Reverse horizontal and vertical motion option.

Note: This does not implement the true "Fixed observer, moving scene" navigation model. It simply reverses the sense of inputs before processing them. That is, up motions will move the camera down and left motions will move the camera right. This is essentially the same as "Fixed observer, moving scene". The object is moved in space, rotated about the selected center of rotation (not about the camera), and the camera can still pan.

Default navigation mode

To select a specific navigation mode for new scene windows, use the setting Default navigation mode for new windows on the 3D Preferences page of the Echoview Configuration dialog box.

See also

Movies
3D window keyboard shortcuts
About scenes
Using scenes
3D Single Targets graph