L3DT v2.1 release announcement

The maximum map size in L3DT 2.1 has increased from 16 million pixels (4096 x 4096) to 1 billion pixels (32,768×32,768). That's equivalent to 107,000 sq km of map (~Tennessee) at 10m resolution.

RAM: The typical RAM requirement is about 50Mb with a maximum of about 100Mb for some operations. The new 'mosaic map' architecture manages the RAM usage by automatically caching to HDD.

HDD: If you have Tennessee-sized ambitions you'll want a Texas-sized hard disk drive. A gigapixel map will take 16 gigabytes of hard-disk real-estate (inc. textures, normals, etc). A more modest 1024 x 1024 map eats only 16Mb.

CPU: You don't need a workstation, but if you don't have a fairly-quick CPU you might need a lot of patience. L3DT 2.1 takes about 2 CPU-days on my home AMD XP2600+ to generate a 1 billion pixel map - including the heightfield, attributes map, water map, normals, light map and texture (the heightfield alone takes ~10 hours). It takes 1 minute 30sec to make a 1024 x 1024 map (inc. texture, etc).

L3DT now does pretty interpolated textures (example one, two). There is also support for user-defined climates & land types. It was all a bit of a last-minute addition and the climate stuff is fairly provisional, but I'll tidy things up in release 2.2.

I've broken the backwards-compatibility with older attributes map files, so it's a good idea to re-calculate the AM for any old maps from release 2. I'm going to re-write the AMF format for release 2.2.

Heightfields can now be imported & exported in a few useful formats:

• The Virtual Terrain Project '.bt' binary terrain format (v1.3).
• The Terragen '.ter' terrain file format.
• 8-bit greyscale bitmaps.
• ASCII text-files (export only).

If you're feeling adventurous you can make interesting terrain by importing photographs as bitmap heightfields (example).

I've changed the format of the L3DT heightfield and water-map files, and I've posted the new file specs on the Tutorial page (in Appendix B)formats page. The file formats are now officially:

• HFF v1.0 file format for heightfield files.
• WMF v1.0 file format for water maps.

L3DT 2.1 will still load the older HFF and WMF formats, but the new ones are much nicer and won't be subject to change for a long time. I therefore suggest you open any old maps and re-save them (2.1 automatically updates the files to the new formats).

Oops! The WMF file spec isn't posted because I haven't quite finished it yet - I still have to debug the run-length encoding.

A beta-version of the new L3DT Viewer (L3DTVi2), written by Stuart Gooding, is available on the downloads page. If you ask me, it's a masterpiece of Delphi / GLScene coding. Top work, Stu!

In addition to L3DTVi2 you can load the maps into Terragen, VTEnviro, or any 3D environment that can load greyscale bitmap heightfields.

I've done a bit of work on the UI (eg click-drag zooming).

Sea-flooding is now 9x to 10x faster than in release 2, but there is a little bug that stops mosaic flooding sometimes. I'm still searching…

I've thrown-in a lot of PeekMessage calls to keep L3DT responsive during calculations. While this does make L3DT a bit slower, it means you don't get the unpleasant 'Not responding' message.

Otherwise it's pretty much the same as L3DT 2.0 .

The tutorial and algorithms pages have been updated. In particular, the tute page has grown quite a bit and now includes a brief 'walkthrough' to get you started.