Making Terrain without DEMs

[pagsab]

Terrain making in SF2 depends heavily on having a Digital Elevation Model to generate the height and tile fields required.  However, I have been frustrated by the geographical distortions produced in so many SF2 terrains by the mismatch between E-W and N-S distances in the underlying DEMs, especially at higher latitudes.  I hence decided to try doing without DEMs by making a terrain the old fashioned way, using maps whose projections minimise the distortions involved.  My Times Comprehensive World Atlas has a double spread showing the Baltic States at 1:2,500,000, perfectly matching the standard 1000 km terrain square in SF2.  I made a high resolution copy of this spread, including the margins so as to reduce the scale slightly and hence fit everything from the Pripet Marshes to Karelia within the 800 km playable area.  I then imported this as a reference map into Gerwin’s wonderful TFD editor, along with blank HFD and TFD files from the TW terrain editor.

To minimise effort, I cannibalised published tiles, objects and target files as much as possible, including the ice floes from Menrva’s Bering Straits terrain.  I tweaked and augmented my tileset to create more villages and towns and to allow smaller islands and sharper promontories than with the gently curving standard tiles.  Mue’s editor made it easy to amend TOD objects, but editing tile images and transparency proved maddeningly difficult until I finally found a way to do so through combined use of GIMP and an old copy of Photoshop Elements.  Gerwin’s editor allows a selected mix of countryside tiles to be pasted and then rotated at random, but overlaying this generic background with more specific tiles is a daunting task given that even a standard 1000 km terrain includes a quarter of a million tiles!  I opted to practise on the 130 km long Swedish island of Gotland, to perfect my techniques before moving to more central areas.

Modelling the island was a very slow process of toggling between the reference and tile maps and selecting and rotating each tile in turn.  Besides doing this along the coastlines (including an outer layer of coastal ice), I opted to model every settlement and small river shown on the Times map, though I drew the line at trying to add roads as well.  The many satellite images accessible on the web will help in guiding the addition of dense forest and small lake tiles in those parts of the region where these features are more common.  In this generally low lying terrain, it is easy to use Gerwin’s editor to add small height steps to entire tiles, to model the relief shown on the very useful elevation maps available at https://en-us.topographic-map.com/.  The picture below shows my summer and winter versions of Gotland, alongside the matching part of the Times map on which they are based.

If SF2 terrain creation were an all or nothing affair, I would give up now, since applying this tortuous process across the entire map would take an impossibly long time.  However, by shifting Gotland temporarily east into the playable area, I have already flown dozens of terrain checking and wingman experience missions in classic 1940 planes over this island alone.  Modelling western Estonia will allow recreation of air missions during the German assault on the Estonian islands in autumn 1941, and in due course I can add further parts of the region to allow my preferred short range real time missions to be flown there also.  My terrain will remain purely for personal use due to its dependence on third party components, so it does not matter that I am unlikely ever to finish this ongoing project.

The real benefit of my experience so far is that I now understand far more than I did before about the creation and modification of SF2 terrains.  The knowledge only increases my respect for the makers of published terrains, while giving me a welcome ability to address perceived deficiencies should I wish to undertake the considerable effort required.  I find maps and military geography especially fascinating, and making or amending SF2 terrains is a very satisfying way of studying the fine details of the real terrain over which the missions we model were flown.

[+Gepard]

Interesting way.

But how about the heightfield of the map? Do you set every single elevation by hand? What means 16 elevation points per tile in 500 m resolution or 64 points with 250 m heightfield resolution.

[VonBeerhofen]

I sometimes used shaded terrain maps if nothing was available for free, often on top of a hand drawn impression of what was visible on the map using printed elevation values. Although it was for a much smaller area in EAW it worked pretty well using advanced drawing options in Photoshop to smoothen or rough up terrain based on what I could gather on information.

It's great fun when you fly over something created from scratch using only one's imagination and a little knowledge. However a DEM is probably a much quicker method.

VonBeerhofen 

[pagsab]

Good question, Gepard.  As I said, I prioritise avoiding horizontal distortion over a detailed heightfield, especially in low lying areas like these where the small elevation differences matter little except to soften the jarring appearance of pancake-flat terrain.  Hence, I usually just raise entire tiles 1 or 2 steps above the default sea level, guided by side by side comparison with an elevation map like that shown below from the website I mentioned.  (I can't simply replace the reference map with this elevation map when setting the heightfield, since its projection differs from my Times map.)  Gerwin's editor does allow one to zoom in and adjust all 16 elevation points individually if desired, but I do this only to stop coastal hills lifting the sea, as seen below in the Hall peninsula or on the northern boundary of Visby airfield. 

My more impressionistic heightfield creation technique does not take that long compared to manually selecting and rotating tiles themselves - it is the latter which limits my method to small bespoke combat areas or isolated island bases such as Midway.  DEMs are undoubtedly far quicker as vonBeerhofen said, though I agree that there is a special satisfaction in creating a terrain manually, where one can escape the limitations of the automatic system and add details like those I have mentioned.  It should be entirely feasible in due course for me to fill out in my terrain the crucial 150 km wide arena between Oranienbaum and Lake Ladoga where the Nazis and Soviets confronted one another for over 2 years and where many bitter air battles too place.   

Edited 5 hours ago by pagsab

[+Gepard]

There was also a methode of using GLOBE DEM instead of GTOPO30 DEM. Something with making the GLOBE data to .raw file, which could somehow be transformed into a .hfd heightfield. But i cant remember how it was done. It's a long time ago.

I can not remember wheter the GLOBE DEM have the same warp effect like GTOPO30 DEM.

[pagsab]

The warping problem certainly seems to have been avoided in a few terrains, notably Baltika's North Cape terrain despite its very high latitudes.  Does anyone remember how?