Guy Jeffries

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Well, why is... those things?

To support the posts that look closely at the Succession Maps , this series is about how these features got there.

In these posts are some development images. They are universally dreadful. They do give you insight into what a project like this looks like through 95% of its development life though.

Like the close look, we’ll start with beaches.

Beaches

The first attempt used existing beach solutions from the software. They did work but were not suited to landscapes of the scale I was after. I needed to be a lot more subtle.

Making the actual beach with sand using elevation and angle produced a result, but not a good one. Also the beached just bunged up the rivers, which they can do, but not exclusively.

It did make nice big sweeping beaches but it didn’t shape the land with the water interacting with harder rock and sliding up the shallows either.

On my mood board was a lot of Cornwall (UK) which has a fantastic crinkly coastline, if you don’t know it, take a look at Lands End on Google Maps and be charmed by the rock strata and beaches.

Back to making maps, this is what one looks like when you just add sea to the large maps. It’s like pouring water over a plastic toy of terrain.

Apart from just slipping into the water like it didn’t exist, the land also played havoc with the maps scale. If this was a crinkly coast of beaches and headlands, at this scale even small mountains dwarf Everest.

What I wanted was smoother coast so it was nice and crinkly but at a lower intensity, more like this.

As you can see this is only part of the solution. The land looked like it reacted to the water, but more like a uniform mud slide than a crinkly coast.

Taking these results and refining them allowed the smoothed edge to be used as a tool.

If you take a ragged edge and smooth it you end up with a softened straighter line.

Using the smoothed straighter line the crinkly one can be sliced, allowing selection of just concave or convex parts of the line.

A crinkly line becomes straighter when smoothed

In the context of a coastline, everything on the sea-edge of that smoothed line was boosted up a little and called headland. Everything on the land side was smoothed off and called beach. In this way headlands became more pronounced and beaches became flatter and softer.

Put them together and what do you get.

Because the beaches and cliffs are often a sub-pixel feature due to scale the beaches have been simplified and brightly coloured. If you look closely you can see grey rock poking out around the coast here and there between the beaches.

As a system it is not infallible and often fails to make beaches and headlands. However, though it fails often, it succeeds often enough to produce a pleasing result for a relatively small processing cost.

These processing costs soon add up doing work at scale and are a major decider of feature inclusion.

I hope this has been interesting. Reach out to @Leapin_guy on Twitter or Leap Interactive on Facebook and let me know what you think.