Screen Camera Track Events

There are three events available on the Screen Camera track:

Set Layer View – switch to a particular pre-defined Layer View at a defined point or points along the Timeline.
Set active Camera – select a pre-defined Camera from which to view the simulation playback.
Add a Snapshot event – save snapshots of the simulation as image files at specified points along the Timeline.

To set a Layer View, at least one Layer View must be defined in the model using LEGION Model Builder; please see Layer Views.

Cameras must be created and named to be used in the Timeline. See the Cameras topic for details about how to do this. It’s also possible to create Cameras based on the current view, directly from the Screen Camera Track

Creating a Camera for the Current View Using the Screen Camera Track

Simply right click in the track area of the Screen Camera Track, and select Create set and Active Camera…
A new Camera is automatically created, based on the current view and the Camera default properties declared in the Cameras, Images, Videos and Maps tab of the Simulator Project Settings dialog. For more information, see the Camera, Image, Video and Map Defaults topic for details.
The Camera properties dialog appears.
- Confirm the preview area, camera centre, field of view and camera aspect ratio are correct, then click OK.
The Active Camera Event properties dialog appears.
- Confirm the new Camera is selected as the active Camera, and that the preview is correct.
- Select the transition mode to use when this Camera is activated. Options are Instant, Coarse and Smooth. See the later section Setting an Active Camera for more information.
- Click OK.
  Note: Clicking Cancel in either property dialog will stop the process and not create or activate the new Camera.

Setting a Layer View

If Layer Views exist in the model (created in LEGION Model Builder), events can be added to the Screen Camera track which display these views during the course of playback. For instance, a Layer View containing Presentation CAD for trains or other vehicles.

To make this Layer visible when passengers alight from trains in a simulation, the Layer View should be switched on at times which match the arrival of trains. To turn the Layer View off for the departure of trains, another Layer View and activation event is needed that revert to a view which does not contain the vehicle CAD lines.

Note: Layer Views are also visible in the saved image file.

To set a Layer View:

Right-click on the Screen Camera track at the time the event is to start and select Set Layer View.
- The Layer View dialog is displayed. The new event and time are displayed in the Registered events box.
If required, enter a name in the Event name box.
To run this event next time simulation is played back or recorded, tick the Enable this event box (or untick it to ignore this event in the next session).
From the Activate layer view drop-down list, select the relevant view.
Click OK to place the event on the track.
- To switch to a different Layer View, repeat the process at the required point on the track.

Setting an Active Camera

Having created Cameras, they are now available for use on the Screen Camera track and Record .AVI events. There’s no limit to the number of Camera events on the Screen Camera track.

When playing or recording a simulation and an active Camera event is reached on the Screen Camera track, Camera changes are visible on screen.

Note: Camera transitions just apply to video recordings and are not saved in Screen Camera track image files.

This procedure applies to Screen Camera tracks and Record .AVI events.

To Set an Active Camera:

Right-click on the relevant track at the time the event is to start and select Set active Camera…
- The Camera dialog is displayed. The new event and time are displayed in the Registered Events box.
If required, enter a name in the Event Name box.
To run this event next time simulation is played back or recorded, tick the Enable this event box (or untick it to ignore this event in the next session).
From the Activate Camera drop-down list, select the Camera to activate at this time.
- No Camera is selected by default. This will generate a QA error until an actual Camera is specified.
Use the Transition Mode drop-list to select who quickly the view changes from the previously active Camera to the one selected in this dialog.
Three options are available:
- Instant (1 frame) – the view changes immediately to the new Camera.
- Coarse (10 frames) – the view pans from the previous Camera to the new Camera over 10 frames. This can result in large positional jumps between each frame, especially when Camera centre points are significantly far apart.
- Smooth (50 frames) – the view pans from the previous Camera to the new Camera over 50 frames. This gives a smoother motion effect between the Camera views, but the transition can be slow for shorter distances between Camera centres.
Click OK to save the event.
Repeat from Step 1 for any other active Cameras that need to be set.

Adding a Snapshot Event

A Snapshot event is only available on the Screen Camera track. This event takes a picture of the simulation at a specified time and saves it as an image file. If there are no active Cameras on the Screen Camera track, the image taken will be of the whole model, otherwise it will use the current active Camera.

To Add a Snapshot Event:

1Right-click on the relevant Screen Camera track at the time the event is to start and select Add a Snapshot event.
- The Snapshot dialog is displayed. The new event and time are displayed in the Registered Events box.
If required, enter a name in the Event Name box.
To run this event in the next play or record session, tick the box labelled Enable this event (see also "Disabling and enabling events before playback or recording" in About the Timeline).
Set the Map image aspect ratio and dimensions:
- The default aspect ratio is 16:9 and the default dimensions are 1920 x 1080 pixels.
  - Select an aspect ratio option from the Image Aspect Ratio drop-down.
  - To enter an aspect ratio that’s not listed, select the Custom option. The custom aspect ratio box appears.
  - Sizes and aspect ratio can be linked when using a custom aspect ratio.
    - When the sizes and aspect ratio are linked, changing one dimension automatically updates the other dimension such that the aspect ratio is always respected.
    - When the sizes and aspect ratio is are unlinked, they are independent and changing a dimension automatically updates the custom aspect ratio. The other image dimension is not changed.
    - To link or unlink sizes and aspect ratio, click the button between the X and Y size boxes:
  - The icon or button here indicates whether sizes and aspect-ratio are linked:
    - this icon (not a button) means sizes are linked to the aspect ratio and cannot be unlinked.
    - this button means sizes and aspect ratio are linked, but they can be unlinked.
    - this button means sizes and aspect ratio are not linked, but they can be linked. Tip: Sizes are always automatically linked to preset (non-custom) aspect ratios. Only custom aspect ratios let you link or unlink sizes to the aspect ratio.
  - Set the preferred image size, remembering the above rules about linked/unlinked aspect ratios.
    - Only numbers can be entered.
    - Invalid values are highlighted by a red border around the input box.
Select one of the three Image Format options:
- JPEG
- Bitmap
- PNG – this is the default format.
  Note: Default sizes and format are declared in the Cameras, Images, Videos and Maps tab of the Simulator Project Settings dialog. See the Camera, Image, Video and Map Defaults topic for details.
To apply these image, format, and Layout settings to all Snapshot events on this particular track, click Apply to all Snapshot events THIS track.

Note: This button is only enabled when there’s more than one Snapshot event on the Screen Camera track.
- A selection dialog appears:
- Click on the items to reuse; hold <CTRL> while clicking to select multiple items.
- Click the OK button. Settings of the selected items are applied to all Snapshot events in the Screen Camera Track in the active Timeline. Selections are remembered and items are automatically selected again the next time this dialog appears.
To change the default Layout of the saved Map image, click the Layout button and make any changes to the Layout.
- The Layout Designer works in the same way as the avi Layout Designer, which is dealt with in Customising the AVI Layout.
Click Apply or OK to save the event.
Repeat from step 1 for any further Snapshot events required.