Luomu: Imported from GH wiki

2012-09-16T21:50:05Z

Imported from GH wiki

New page

Height maps live in data/heightmaps/*. There are currently two types. Each type has a different data structure and is modified by a different fractal height/color combo. Type is specified by the second argument to the <tt>height_map</tt> function in the custom system definition.

== Type 0 (eg Earth) ==

<pre>
struct HeightMap0Header {
Uint16 width;
Uint16 height;
};
struct HeightMap0 {
HeightMap0Header header;
Sint16 data[header.width*header.height];
};
</pre>

Notes:

* Traditional docs claim height is in metres, but the sign appears to be important. I expect that means 0 is actually some 2^16m (~65km) from the "surface".

== Type 1 (eg Moon) ==

<pre>
struct HeightMap1Header {
Uint16 height;
Uint16 width;
// height = height * scaling+minheight
double heightScaling;
double minh;
};
struct HeightMap1 {
HeightMap1Header header;
Uint16 data[header.width*header.height];
};
</pre>

Notes:

* Uses scaling and minimum height to provide a wider range of heights
* Data is ''unsigned'' (because of the minimum height)
* width and height are ''reversed'' from Type 0

Planet Heightmaps - Revision history

Luomu: Imported from GH wiki