Request for documentation

From pull request qgis/QGIS#55332
Author: @wonder-sk
QGIS version: 3.36

Add "Render as a surface" option to 2D point cloud renderers

PR Description:

When enabled, we will do Delaunay triangulation of the points in the current map view, and then render triangles instead of points. For each point we keep its color for interpolation in the triangle.

Global map shading is also supported with the new option, when enabled, we also keep elevation of each point, and then rasterize triangles with interpolated elevations to the provided elevation map.

When "Render as a surface" is enabled, drawing order is ignored, because points do not obscure other points anymore - all input points participate in the triangulation.

There is also an option to filter large triangles (given by the maximum length of edge of a triangle), which is useful when one wants to see the actual holes in the data. Compared to the implementation for 3D rendering, the 2D rendering only provides filtering based on horizontal length of triangles. Filtering based on triangle size on the vertical axis seems irrelevant because the 2D view is always from the top.

Funded by: National Resources Canada

GUI

There's a new group in 2D styling tab - similar to the one that already exists in the 3D styling tab:

Screenshots

As expected, triangulation covers holes between points when zoomed in, but subjectively also gives nicer rendering when zoomed out.

Trencin castle

Disabled	Enabled

Global map shading when render as a surface is enabled:

With map shading	With map shading, only ground, filtering large triangles

Helsinki train station (RGB)

Disabled	Enabled

Commits tagged with [need-docs] or [FEATURE]