Layers

Layers in Builder are connected to data sources and are used to render features on a map by directly connecting to your data warehouse. Once a data source is added to Builder, a layer is automatically added for that data source. If the spatial definition is valid, the features will be rendered on the map. Learn more about defining source spatial data in this section.

Layer options

When working with layers in Builder, you have the following options:

• Zoom to: Zoom to the layer extent, taking into account any filtering applied in Widgets and/or Parameters when applicable.

• Show only this/Show all layers: Easily set layers visibility on and off.

• Layer style: Access the layer panel to set your layer styling configuration.

• Duplicate layer: Duplicate a layer with the same styling properties.

• Rename: Edit the name of your layer.

• Delete: Remove the layer and its corresponding source.

Visualization types

The spatial definition of the source linked to a layer specifies the layer visualization type and additional visualization and styling options. The different layer visualization types supported in Buider are:

• Point: Displays as point geometries. Point data can be dynamically aggregated to the following types:

  • Grid: Aggregated point geometry to grid.

  • H3: Aggregated point geometry to hexagonal cells.

  • Heatmap: Aggregated point geometry by density.

  • Cluster: Aggregated point geometry by circles.

• Polygon: Displays as polygon geometries.

• Line: Displays as line geometries.

• Grid: Displays features as grid cells.

• H3: Displays features as hexagon cells.

• Raster: Displays a grid of pixels.

Visibility by zoom level

Control the zoom range where a layer should be visibile. This is useful for combining different type of sources, such as aggregated data for lower zoom levels and non-aggregated data for higher levels or visualizing different administrative levels.

Aggregate by geometry

If you are working with point, polygon or line layer visualization types containing identical geometries with varying attributes (e.g., weather stations or buildings), you can use the Aggregate by geometry functionality to aggregate your layer based on a distinct spatial column. This allows you to:

• Aggregate geometries in your layer ensuring an optimal performance.

• Aggregate styling and interaction attributes to retrieve relevant information link to your aggregated feature.

• Maintain widgets functionality over the original source, enabling drill-down operations for deeper insights.

Layer styling

Layer styling is essential for making your maps informative and engaging. Below are generic aspects of visualization and styling options available in Builder. For more detailed styling capabilities for a specific layer type, we recommend to check each layer type as defined above.

Color palettes

When styling layers in Builder, you can choose a few different types of color palettes:

• Diverging: Highlight values that are above and below an interesting mid-point in quantitative data. This is a great way to show data values that differ greatly from the norm. For example, you may use a diverging colour scheme to show population change.

• Sequential: Ideal for data that follows an order, often numeric ranging from low to high. For example, you may use a sequential colour scheme to show counts within a H3 grid.

• Qualitative: Represents different categories of data. For example, a qualitative scheme is a good choice for showing different types of Points of Interest.

• Singlehue: Gradual transition of a single color from light to dark. For example to visualize the quality network coverage signal.

• Custom: Pick a new color either by clicking on the color picker or inputting HEX/RGB values. Color steps can be added, removed and shuffled.

When working with aggregated data sources, you will need to select an aggregation operation for your columns.

Connections to Redshift clusters only support aggregation of categorical properties by any value.

Admins can also create custom color palettes from the organization settings. These are reusable color schemes and they are available to the whole organization, removing the need to define a new custom palette every time a custom set of colours is used for styling.

For more information, see our article on custom color palettes.

Color schema by HexColor

You can also tap into the HexColor feature to style qualitative data using the hex color codes from either your table or SQL query source. To harness this capability:

1. Navigate to the Color based on selector and choose the text column you want to associate with the hex color code.

2. In the Palette section, select the 'HexColor' option.

3. Finally, choose the column containing the hex color code values.

For more information about how to leverage this functionality see this tutorial.

Pre-generated tileset layers styled with HexColor are not currently supported in the legend. If you require this functionality, please provide feedback through your CARTO point of contact.

Color Scale

Depending on the property selected to define your color schema, you have different color scale functionalities to define the color classification method.

For numeric columns, you can choose the following data classification methods:

• Quantile: A quantile color scale is determined by rank. A quantile classification is well suited to linearly distributed data. Each quantile class contains an equal number of features. There are no empty classes or classes with too few or too many values. This can be misleading sometimes, since similar features can be placed in adjacent classes or widely different values can be in the same class, due to equal number grouping.

• Quantize: A quantized color scale is determined by grouping values in discrete increments. It allows to transform an initially continuous range into a discrete set of classes. Quantize scales will slice the domain’s extent into intervals of roughly equal lengths.

• Logarithmic: A Logarithmic scale based on powers of 10 will be created automatically, based on the number of steps in the selected color palette. Logarithmic scales tend to work well with aggregated data sources.
• Custom: A custom color scale is determined by arbitrary breaks in the classification. A custom scale is well suited to tweak color ramps, adjusting the values to fine tune the visualizations.

For text columns, you can use the Ordinal classification method to set a specific category to each color value:

3D visualization using Height

Builders allows you to assign heights to build 3D visualization for both polygons and spatial index sources. You can activate this option in the Height section, using the slider to define a fix value or using a property to define the height.

When using the Height functionality, remember to activate the 3D view located in the toolbar above the map. Using this, you can achieve stunning visualizations as per below map.

Explore a map with 3D polygons whose height is defined by the number of floors.

Layer blending

Layer blending is a technique used to determine how overlapping features in different layers interact in terms of their visual representation. When two layers are blended, you can select the following blending options:

• Additive: This mode adds the color values of overlapping features. When two colors are added together, the resulting color is often lighter. This blending mode is commonly used to visualize densities or intensities.

• Subtractive: This blending mode subtracts the color values of the upper layer from the layer beneath it. The result is typically a darker color. In some contexts, this mode can help emphasize differences between layers.