Trouble with horizontal scale

[Mathius]

Hello,

I'm trying to create a custom heightmap for use with a particular game, but before I even get started learning L3DT I'm trying to get it setup for the parameters required by the game. In setting up the map, I'm required to use a horizontal scale of 1.8288221359252928. Now I don't know where this number came from or why it helps to be that exact, but I find that when I enter that into L3DT's field when setting up the map it cuts it off at 4 digits. When I go into operations>heightfield>change horizontal scale to try to change it after the fact, that field is grayed out and I can't select it. I'm using the newest L3DT standard version, v11.11.

Can someone help me out with this?

[Aaron]

Hi Mathius,

I apologise for this fault. The heightfield wizard should accept more decimal places. It will probably take me a few days to make these changes, but I'll post back here when it's done.

My guess for the origin of that number is that the game uses a horizontal scale of 6 feet, and someone has zealously converted that into metres without thought to the required precision (6ft = ~1.8288m). One of my first year physics lecturers had a good 15 minute tirade about that sort of thinking and calculation, but I'll spare you a recount. Anyway, I would be greatly surprised if there was any detectable difference between using the 16 significant figures you quote, and, say, 6 sig. figs. L3DT internally stores the horizontal scale as a 32-bit floating point number, which gives 8 significant figures, or about one part in 100 million precision. Over a distance of ten kilometres (~6mi), say, that format gives a precision of about 100 microns; the width of a human hair. The number you quoted looks like a double-precision float, which gives precision of about one part in 10 quadrillion. Over one thousand kilometres (~621mi), that's equal to roughly the diameter of an atom. It is difficult to see how a game could require the specification of positions to atomic precision over continental distances, or if a player could possibly discern the difference.

Moreover, what map file format are you exporting from L3DT into the game? Does it store the horizontal scale with 16 significant figures, or is the scale number going to get truncated when saved anyway?

Best regards,
Aaron.

[Aaron]

Hi Mathius,

The heightfield size wizard has been updated to accept more decimal places. The change will be included in the next release, and is currently available in the latest developmental build of L3DT Pro (v13.10 build 0).

Best regards,
Aaron.

[Mathius]

Wow, sorry. Your questions are way above my pay grade I'm way new at this stuff. Basically I'm trying to create a heightmap that I can use to create a world for the game Skyrim and I'm following a tutorial. Using the landscape editor in the creation kit to create everything from scratch was exhausting.

Thank you for looking at my issue. I'm sure I'll be asking more questions as I have zero experience using this program or even working with heightmaps. Do you have any kind of tenative date as to when the next release will be?

[Aaron]

Hi Mathius,

I'd like to get the next release out before the end of year, but I've not set a date yet.

The updated heightfield wizard, with more decimal places, is in the latest developmental build (13.10.0.1), which is on the downloads page now.

Best regards,
Aaron.

[Tamb0]

I'm assuming the OP is creating maps for Skyrim.

Just to clear thing up, it doesn't matter that much if the horizontal scale is not exactly 1.8288221359252928. You can just as easily set it to 2 and you'll never notice the difference ingame. Curves become more blocky when using a horizontal scale of 4 or 5, but these can be smoothed out using the CK Landscape Editor.

I've created dozens of maps for Skyrim using L3DT and I've found that you can use a maximum horizontal scale of around 5m before the terrain starts to tear.

The biggest test I done for Skyrim using L3DT was creating the British Isles from SRTM data. For this I had to use a horizontal scale of 5m (reduced from ~93m horizontal scale). To keep everything in shape, the mountains also have to be scaled down, so the map wasn't really usable. The highest peak (Ben Nevis) only ended up around 100m high

16384 x 16384 (the largest that the Skyrim engine can take) - http://homepage.ntlworld.com/tambos.turf/Skyrim/Britannia.jpg