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 Sunday at 08:37 PM 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? 

[pagsab]

As I said in previous threads, my discovery of how to fly as a wingman has hugely increased my enjoyment of SF2, and it is even more fun over my own detailed terrain.  I don't have any Swedish planes of the era, but I hypothesise that the Finns may have sent a few on detachment to Gotland in autumn 1940, to show solidarity with their Swedish allies from the Winter War after Stalin annexed the nearby Baltic States that summer.  Here I am in a Morane Saulnier 406, enjoying a low level circuit of the island with my leader as we cross back from Faro to Gotland itself.  The small port of Farosund is just above my wing, and to its right may be glimpsed one of the low hills I have added.  ShrikeHawk's Continuation War conversion in the downloads section of this site is a good source of relevant files.

 

[+Menrva]

On 1/11/2026 at 9:51 PM, pagsab said:

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? 

I think just by manually editing (resizing etc.) the heightmap bitmap, I did that for the Italy/Balkans terrain I released. Of course by doing so further raw details of the original heightmap are lost. I'm not aware of a better and feasible way to do it when starting from DEMs.

[pagsab]

Thanks for telling us.  I did wonder if editing the HFD bitmap to remove the distortion would work.  It is well worth trying this if I get the chance.  In the meantime, I am enjoying the freedom in my current manual project to create tiles which would stymie the automatic tile placement system.  I have now added a few dozen extras in total (all with summer and winter versions), by tweaking the existing tiles which I have cannibalised.  These additions make it a lot easier to model real features such as narrow peninsulas or lakes near the coast.

I realised today that Google maps are more useful than satellite images in identifying where to place lakes or dense forests.  (Zooming out a little helps with the latter, since it reduces the confusing welter of intermediate indications.)  I have now added some forests on the south and east coasts of my Gotland model, as well as 8 new single- or multi-tile lakes in addition to the one shown on my Times map.  The Times map is still better for showing rivers and for deciding which of the many settlements of varying sizes it is worth including in my terrain.  I will never approach the level of your gorgeous Italy terrain with its bespoke lakes etc., but I have now achieved enough in this initial trial of my manual technique to be able to move on to model real air battle arenas in Estonia and elsewhere.

I searched today for information on WW2 airfields in the Baltic region, and I was amazed by how much is available online.  Henry de Zeng has made a stellar contribution at http://www.ww2.dk/lwairfields.html by posting his encyclopaedic research into Luftwaffe airfields in every theatre.  This confirms that many more airfields existed than are modelled in SF2 terrains, but that the great majority were simple cleared squares of grass or dirt rather than big and elaborate constructions like those needed by the jets which are SF2's primary focus.  As an experiment, I placed a single grass tile without trees in my Gotland model, and created an airfield there in my targets.ini with no objects whatsoever, referring to a barebones airfield.ini with nothing except takeoff and parking info.  The field worked a treat, and it is easy to add minimalist airfields like this in any WW2 terrain to allow fighters and attack aircraft to operate from just behind the front lines.

[+Stratos]

That made me thought about an idea I had long time ago, where instead of huge maps try to create a smaller map of a single country but more detailed, you know modeling roads, villages, towns, etc. Seems you did something similar for Gotland.

[+Gepard]

2 hours ago, Stratos said:

That made me thought about an idea I had long time ago, where instead of huge maps try to create a smaller map of a single country but more detailed, you know modeling roads, villages, towns, etc. Seems you did something similar for Gotland.

The map cant be to small. You have the "invisible" wall of 80 km of the edge of the terrain, what means, that you lose 160 km airspace, which you cant use. If you give 200 km space for each side, then you have a minimum size of 560 km, lets say 600 km for the map.

My experience is, that 1.000 km maps are the best compromise between size and workload for creating a detailed terrain.

[+Menrva]

18 hours ago, Gepard said:

The map cant be to small. You have the "invisible" wall of 80 km of the edge of the terrain, what means, that you lose 160 km airspace, which you cant use. If you give 200 km space for each side, then you have a minimum size of 560 km, lets say 600 km for the map.

True, and it's not only about the invisible wall. I tried porting the very small maps of First Flight: The Wright Experience Flight Simulator (2003), a game based on the engine of Strike Fighters Project 1, but they crash the game, such small sizes simply are not supported by the game engine of SF1/SF2. There must be some hardcoded values about allowed terrain sizes in the game's code.

[+Stratos]

As small map I mean detailed area, you know, area populated with targets, roads, villages, etc. For example, populate all El Salvador, and play COIN there, even If the neighbouring countries are not populated.

Just a way to have a more detailed area for relatively low level fight. COIN warfare, dogfights with underdogs planes...

I even dreamt adding small low poly cars of the proper era as TODs on the roads to add the sensation of civilian traffic

[pagsab]

My experience with Gotland shows that one can fill in just a small proportion of a standard sized terrain, and have many enjoyable flights there.  The area can be kept nice and central, well away from the wall.  However, I am now discovering the severe limits of my old-fashioned Times map, through detailed perusal of the satellite view on Google maps.  I had naively assumed that the Times cartographers had selected settlements based on size.  It turns out that some are significant small towns but others are barely discernible in real life, having just a few scattered houses.  The ideal instead would be to have the Google satellite view linked to Gerwin's editor, so it could be panned and zoomed in conjunction with the tile map.  That way one could place town, lake and forest tiles exactly where appropriate.  Roads are clearly visible in this satellite view, but small rivers are far harder to spot, and in hindsight most of those marked on the Times map are unworthy of representation.

I clearly need to rethink my approach before proceeding with my manual terrain project.  I think I will ditch the Times map and patch together a reference map instead from screen grabs of the zoomed out Google map.  I will also narrow the width of Gerwin's editor so that I can run it side by side with an internet window showing the Google satellite view or the online elevation map I mentioned.  These may be panned and zoomed independently to focus in on the area I am currently editing.  That way I won't need to squint to discern the real terrain (except rivers), and I can gradually build up a representation which is as accurate as the severe limitations of an SF2 tileset allow.  I will probably take the opportunity to reduce the scale a little more so that the playable area extends from Warsaw to Moscow, giving ample scope for scenarios on the northern half of the Eastern Front.  Gotland has served a very useful purpose as a trial, but I have no intention of spending any more effort on the 36% of any SF2 map which is inaccessible - it will be hard enough to fill out more than a small proportion of the central area using my manual technique!

 

[+gerwin]

I assisted Wrench with this terrain at the time. 

Used Xplanet software to convert rectangular DEM format to a Spherical image.

October 20, 2013: "Here is Norway and the North sea in gnomonic projection. As a TFD file. Silimal to Germany CE in scale, and 1500x1500km.  A Part of  Iceland is still visible on the top left."

 

 

[pagsab]

Thanks for explaining how the lovely Norway terrain overcomes the warping problem.  I have flown over it often, but unfortunately, combat missions across the North Sea and back take much longer than fits with my real time approach.  My current focus on the Eastern Front stems in part from the greater proximity of the opposing forces at any one time.  I just read that Stukas sometimes managed 4 complete attack sorties within 2 hours.  I tried such sorties last night, and dive bombing is well modelled from my own pilot's perspective.  Getting my AI colleagues to do it is not so straightforward...   

[VonBeerhofen]

PAGSAB's efforts remind me of small battle areas created by some modders for EAW, like RAF_Roy's mini theatres which amused many online players. Like Stratos I also played with the idea of small and more detailed maps which crams all possible targets into this small area and allows the use of every possible tile to create the scenery. It can improve both target density and object density and may be more realistic to fly in. It's definitely an interesting approach but then again I don't think it will capture people's attention for very long unless more such detailed areas would be created. In EAW I soon lost interest attacking the same targets again and again as there were no dynamic changes which could surprise players, and on top of that part of the game's difficulty was lost relating to engine management over longer distances and flying over into danger depending on the front lines.

As for creating battle areas it's nice to be precise but you have to work with what you can get (for free) but when I got my hands on NASA elevation maps I converted them to my game and created a few appropiate tiles for it, just for fun. Wasn't to hard to create a few weird UFO's and wehey EAW's Martian Air War was born. In short, I use anything, even the above map if I have time to work on it. Thx for that.

VonBeerhofen

[pagsab]

Yes, the fun (and learning experience) lie at least as much in the terrain creation itself as in the resulting sorties.  Although I have barely scratched the surface of the huge range of missions which can be flown across the many published terrains, it is satisfying to do it oneself for a change.  As I said, I won't be able to post my own effort, and my aim in this thread was rather to inspire others to tweak terrains for personal use if desired, to create their own preferred 'sandbox' using the wonderful flexibility of SF2.

[VonBeerhofen]

Yeah, it is a lot of fun and educational in many ways, as well as a lot of work. Keep up the good work, perhaps one day you can instruct others on how it's done. Good Luck!

VonBeerhofen

[pagsab]

Many thanks.  My terrain projects are currently veering away from small but detailed full scale vignettes like Gotland, and towards reduced scale terrains which will make recreation of longer range missions more practical within my real time approach.  As I said, I have taken advantage of my shift to Google maps by extending the scope of my Eastern Front terrain south to Warsaw and east to Moscow, while retaining the standard 1000 km pattern.  For a possible follow-up project on the similarly low lying region of NW Europe I have gone even further, creating a Google reference map whose nominally 800 km wide playable area stretches from Brest to Berlin and from St Nazaire to Kristiansand.  This will allow much less protracted sorties than on the standard EuroWW2 terrain, whose 1500 km dimensions mean that it is actually full scale along the E-W axis (just like the Norway terrain).  The corollary is, of course, that my tilemap will have a much lower resolution, but this has the significant benefit that it makes it more practical for me to create each successive stage of the terrain, starting with short cross-Channel hops and building towards 8th Air Force raids on the Biscay U-boat bases and on Germany itself.  First, I will hone my approach on the Baltic, which is looking a bit less intimidating thanks to its own intermediate scale reduction.