Heatmap vector styling

A heatmap represents the spatial density of points that are visualized across a color ramp. The heatmap vector style can only be applied to point or multipoint vector geometry types.

As an example, the following screenshot uses a heatmap on a city population point layer to visualize the density and distribution of population in the United States of America:

To create a heatmap, open the style properties of a point vector file and select Heatmap as the renderer. The heatmap vector renderer has five settings (as shown in following screenshot) that determine how the heatmap will display:

Color ramp sets the color ramp that will be applied across the heatmap. The colors on the left-hand side of the color ramp will represent low density, while the colors on the right-hand side of the color ramp will represent high density. 

To reverse this, click on the color ramp. In the Select Color Ramp window, click on Color 1 and change this value to Transparent:

The following is an example of a heatmap rendering for population by cities:

Rarely is the default heatmap satisfactory, so it is recommended to iterate different values of the radius to create the most impactful, and meaningful, heatmap.