04: Working with Layers

Overview

This lesson introduces Content Layers. You will learn about the different types of Content Layers available in Chyron Weather and how to use them.

Prerequisites: Lessons 01 and 03

Types of Layers

There are two types of Content Layers: Screen referenced, and Geo referenced.

Screen referenced content layers

Screen referenced layers are layers containing content which is using Screen coordinates for positioning of objects. It is a Cartesian space (think x, y coordinates).

The position of a screen referenced object is fixed to the screen and will not move with a zoom or translation of the map.

Screen referenced layers are identified by a light blue color:

Image description: Lesson 11 Screen reference Content Layer

Geo referenced content layers

Geo referenced layers are layers containing content which use Geographical coordinates for positioning of objects. That is, latitudinal and longitudinal values are used.

The position of a geo referenced object is referencing a specific geographical location considering the projection. For example, if you change the map cutout, the object is moving with the map. The geo focus (see lesson 07 for more info) can also affect the position of the objects in the geo layer.

Geo referenced layers are identified by a mid-blue color:

Image description: Lesson 12 Screen reference Content Layer

Geo layer projections

Several projection types are available to transform the sphericity of the earth to a plane. Mercator is the most used, as it is very common but land masses near the poles appear much larger than near the equator. Therefore, a different projection might be necessary when showing a place near a pole.

Image description: Lesson 13 Changing the projection of a geo layer

By default, the projection of Geo referenced layer is taken from the Subscene or GeoBackground it was created from. However, it is possible to define a different projection by browsing to the Projections folder within the DesignModel and selecting an alternative projection.

Which projections are available is defined by the design. Usually the selection is limited to one or two. However, Chyron Weather supports all these projections:

Image description: Lesson 14 Projections configurable

Managing several Geo layers

Using a single Geo layer is like moving one map. You can define a different map cut out and zoom for each segment (see lesson 07). The transition between several segments can be an animation (pan and zoom on the map) or a hard cut.

If several types of projection are required for a presentation, several Geo layers must be used.

Lesson 4.5 illustrates two Content Segments. The first Content Segment shows a map using a Mercator projection, the second Content Segment shows a map using an Orthographic projection.

Image description: Lesson 15 Two segments with different projections

Pan and zoom between two map cut outs of different projections is not possible, only a fade or hard cut. It is not possible to show content of different geo layers within one segment – to switch from one to the other, one of them needs to be empty for that segment.

Note: Only one Projection can be used per Segment.

Image description: Lesson 16 Several Geo projections

Working with Layers

Creating content layers

Content Layers are automatically created the first time you add content (a Content Object) or a GeoBackground to the Storyboard.

For example, clicking and dragging a Subscene onto the content layer stack of the Storyboard will create a new Layer based on the type of object the Subscene contains (screen referenced, or geo referenced). In this way, the layer type reflects the content type.

If a layer already exists, Chyron Weather will ask whether you want to create a new layer or add the content to an existing layer. The former is indicated by a green bar, the latter by a grey bar.

Both options are visible in Lesson 4.7:

Image description: Lesson 17 Creating or adding Content Layers

Hide and delete a content layer

To toggle the visibility of a Content Layer, click the Hide button (the eye).

To delete a Content Layer, click the delete button or select a layer and press the delete key: Trash bin.

Image description: Lesson 18 Hiding a Content Layer

Hierarchy of content layers

Content Layers form a stack. As such, there is an order or hierarchy of layers.

The lowest layer in the stack can be thought of as the bottom or background layer, with additional layers stacked on top (or in front). Lesson 4.9 shows a Geo layer at the bottom of the stack, with a Screen layer on top. Likewise, the content of the layers appears stacked – in this example, the text is placed on top of the map.

Image description: Lesson 19 Content Layer hierarchy

There can be several Content Layers of the same type.

Lesson Activities

Quiz

Questions

Question 1: Which layer overlays the other(s)? A. The light blue layer B. The topmost layer C. The lowermost layer   Question 2: How many segments are needed to show two different geo layers? A. Exactly two B. At least two C. Any number   Question 3: Why using different projections can be useful, when different map cutouts are shown? A. To use two maps with a big latitudinal (north-south) difference B. To zoom into a map cutout C. To make a hard cut between two maps

Answers

1. The correct answer is B. 2. The correct answer is B. 3. The correct answer is A.