Properties for the 3D Graphics Window - Advanced

Min Visible Distance. Specifies the minimum viewing distance in meters.

Max Visible Distance. Specifies the maximum viewing distance in meters.

Far/Near Ratio. A ratio that determines the visual quality in the viewing volume. Lower values increase the visual quality. The default value is 1000, and it is not recommended that this value be changed.

Field of View. Defines how much you can see, in degrees, in the 3D Graphics window. The larger the value, the more you can see. The maximum angle is 160 degrees. A large field of view is similar to a wide-angle lens in photography, where size differences are exaggerated due to proximity to the camera. A small field of view is similar to a telescopic lens.

Use WireFrame Mode. If selected, displays all polygons as wire-frames. This is useful for checking the complexity of the models in a scenario.

Hide Cursor. The cursor may display in output images on certain computers. In those cases, you can stop the cursor from displaying by enabling this option. If selected, the cursor does not appear in output images when recording and using window snap options.

Use Joystick. If selected, enables you to use a joystick, in addition to the mouse, to navigate in the 3D Graphics window.

Use. If selected, uses the depth cone for viewing from above the Crossover Altitude and the depth buffer for viewing below the Crossover Altitude. If not selected, uses only the depth cone.

The depth cone prevents items from sinking into the central body. This works well for surface items, such as latitude and longitude lines. However, it does not work well for below-surface items, such as a Terrain with negative altitude values. The depth cone also improperly displays the horizon when viewing from low altitudes. You can correct these conditions by enabling STK to use the depth buffer for low altitudes.

The depth buffer properly displays the horizon and prevents displaying below-surface items.

Crossover Altitude. The crossover altitude at which the depth cone or depth buffer is used.

Use. If selected, display and records in stereo.

Type. Specifies the type of stereo display.

• Red/Blue Stereo. Displays Anaglyph 3D in the 3D window. You will need red/blue 3D glasses to see the 3D effect.
• Side by Side.Displays left eye and right eye views beside each other in the 3D window.
• Left Eye View. Displays only the left eye view in the 3D window.
• Right Eye View. Displays only the right eye view in the 3D window.

The Left/Right Eye View stereo recording is for Advanced users only. They offer full color, full resolution access to the left and right views, which are not available in the other stereo modes. Using these options you can create a view path, and render two movies: one from the left eye of that view path and another from the right eye of the same view path. The two movies could be post-processed to be in virtually any format needed to drive stereo viewing equipment. Some additional handling is needed to get one video stream to the left eye and the other to the right eye.

• Virtual Reality Device. Allows you to use an Oculus Rift VR headset with STK.

If selected, this enables STK to display to the Oculus Rift headset and attach the Rift head-tracking to the STK camera. The scene as viewed through the Oculus Rift also is mirrored on STK's existing 3D window.

Head-tracking allows the user to turn their head to look around the scene with the camera in a stationary position. The oculus controllers (either the "Oculus Touch" or basic Xbox controllers) can be used to move the camera's position within the scene. The two analog joysticks are used for this purpose.

The left analog stick controls the camera's basic position. This is equivalent to a left mouse click + drag.

The right analog stick controls the camera zoom. This is equivalent to a right mouse click + drag or using the mouse scroll wheel.

• OpenGL View. This option is available only if your system supports the quadbuffer stereo mode.

  To effectively use the Open GL View option, you must first enable the Support Stereo Viewing option at the application level before creating the 3D Graphics window in which images are to be captured.

Eye Separation Factor. The default eye separation factor is 0.02. Increasing this number will increase the overall left/right eye separation, which makes the image appear to have more depth.

Care must be taken when increasing the Eye Separation Factor. If the value is too high, the separation between distant objects will be wider than the distance between the viewer's eyes causing the image to be put of focus. Also, if the separation is too large, viewers cannot focus on distant parts of the image and may experience eyestrain while attempting to do so.

Having too small of an Eye Separation Factor causes the image to appear not as "deep" as it should look and distant objects, such as stars, to appear to be very far away. But the image still appears to be three-dimensional.

The correct setting for the Eye Separation Factor is actually dependent on the physical size of the display on which the image is shown. A relatively large setting, like 0.08, might look fine on a small monitor where the separation works out to be only about an inch or so, easily less than the distance between the viewer's eyes. The very same image, displayed on a giant wall projection system, may produce a separation of several inches, growing larger than the distance between the viewer's eyes.

Auto-Stereo. If selected, the Projection Distance setting is disabled, automatically setting the value to the distance between the "From" and "To" objects in 3D Graphics window. When the camera zooms in or out, the object may appear to grow and shrink (staying in the screen) rather than move closer or farther from the viewer.

Projection Distance. When displaying in stereo there are two virtual cameras, one for the left eye and one for the right eye. These cameras both look in the same general direction, each aimed at a point a fixed distance away. This distance is called the Projection Distance. It should be about the same distance that the cameras are from the nearest visible object.

Objects in the 3D Graphics window that get closer than the projection distance will appear to pop out of your monitor in 3D. If this is done carefully, it can create a dramatic 3D effect. If it is pushed too far, the 3D effect will break down or cause eye strain.