News for July 2005

Release 2.3b is chugging along nicely. The dev plan, recently updated, lists the features and fixes that are ready-to-go, and those still unfinished. Some highlights include:

I made a few mods to the erosion routine, and it now gives better results for the same calculation time. Although I could use this extra efficiency to increase the speed of the calculation, I'm leaning towards increasing the default erosion strength and preserving the calc time. Which would you prefer? Faster or better, or a little of both? (let me guess - you want an interface so that you can choose, right?)

The current release of L3DT produces really lumpy-looking terrain when you use large horizontal-scale values for the heightmap (eg 500m/pxl, 10km/pxl, etc). This is because the strength of the peak-overlay algorithm ramps-up linearly with horizontal scale - which is fine for small values (eg 0.1m…10m), but becomes ridiculously for large values (>100m). I've modified the strength equation so that it asymptotes to a maximum value for large horizontal scales (S = MaxVal × (1 - e^{-λ×HorizScale}), for the math nuts). It seems to work OK across the tested range of 0.1m/pxl to 10km/pxl.

Also, the standard climates bundled with L3DT don't work very well when you use very small horizontal scale values (eg 25cm/pxl). I've re-balanced the temperate climate to be better-behaved, and I've also made a new climate file specifically for these small-scale maps (again based on 'temperate').

The was a nasty intermittent bug in the 'Export to Enviro' feature that sometimes garbled the file paths and caused odd errors. I think I've now fixed this, but some serious evaluation is required.

There was also a bug in the progress display dialog box that sometimes spewed thousands of 'CMapWrap::GetPixel' errors. It was a concurrent thread access problem, which only ever showed-up on slower CPU's (eg 450Mhz). I think I've nailed this one, but I'm waiting for confirmation of this.

Some good progress has been made on the function to export the texture-blending alpha-maps as RGBA images. The difficult part was building an interface to allow users to combine different texture layers into the same alpha-layer. This is to allow users to reduce the number of alpha layers from the 16-or-so typically used by L3DT when generating textures, to something more manageable for run-time blending (eg 4 layers in an RGBA image). Like most L3DT interfaces, it's probably not very intuitive. I'll smooth the rough-edges once I have some user feedback…once it's ready, that is.

Probably 1-2 months from now. I want to debug this one thoroughly.

Release 2.3a is patches the known faults introduced with release 2.3 (see release history). In particular, there were a few bugs in the new 'wizard' dialog system and some of the underlying 'glue-code' scripts. These have been fixed.

I've also included a new presets bar at the bottom of some wizard dialogs. This allows you to store and recall your favourite combinations of settings for particular algorithms, and also change the default settings.

L3DTVi2 has been updated to support recent ATI graphics cards.

The installer has been re-written using NSIS. Aside from being less buggy, this installer also (optionally) installs L3DTVi2 and the off-line tutorial docs.

L3DT 2.3b is planned to include texture splatting and anti-aliased shadows (see dev plan). I intend to hold back on the release until at least October, so I may have time to indulge in some feature-creep.

I'd like to give a big cheerio to the members of the still-shiny-and-new L3DT users' group, who reported and helped diagnose many of the bugs now fixed in this release. Their perseverance and patience was great, and was greatly appreciated.

The wizard dialog rendering problem (see image) has been identified, and a partial solution is available (see bug list). Many thanks go to Michael H. and Andrea M. for their assistance in tracking down the bug (and for their patience). A more thorough bug-fix is on the way.

I shit you not. One of these little buggers [wikipedia] chewed its way through four coolant hoses on my beloved automobile. Not little nibbles either - there are big, big holes with teeth marks. I'm guessing the bastard was after the ethylene glycol [ibid], due to it's sweet sugary taste. Unfortunately for Mr. Possum - whom we may assume did not read the materials safety data sheet [www.sciencestuff.com] - ethylene glycol is toxic if ingested, and may cause disorders of the central nervous system. Damn shame, that.

Oh yes, a retrospective coarse-language warning applies to this post. If small children or the elderly are reading this site, please cover the offending words using a marker pen or equivalent. Thankyou.