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New European Freeware terrain meshes

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Anyone tried any of these new free European meshes ? I'm glad to see we have at last got some freeware mesh this side of the pond.I do like the UK mesh, however I see an odd effect on hillsides. It's like the hill is stepped. Is this a normal side-effect, or maybe a problem ?regards , Tony

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Hi Tony.I'm assuming you're writing about the LOD10 meshes from Josiah Haut.He used Martin Wright's FStrn program to create them. The data was from Gtopo30 data. He interpolated the data to create additional datapoints, and oversampled resulting DEM.What all this means is he took data that should have been LOD6 or LOD7 at most, and then created a bgl that was many times finer than intended. This is no different than commercial projects that use Gtopo30 data. The extra points are not accurate, but produce an exaggerated terrain effect. Some simmers like the effect.If you like the mesh, but don't like the stepping, then turn down some sliders in your display setting screen, until you like what you see.

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>What all this means is he took data that should have been >LOD6 or LOD7 at most, and then created a bgl that was many >times finer than intended. This is no different than >commercial projects that use Gtopo30 data.In case there's any confusion, can I just point out that not all commercial projects use GTOPO30 data. I'm fairly certain that Raimondo Taburet doesn't, and neither do Visual Flight. Take a look at the demos from either of these commercial producers (and probably others) and you'll see a big difference.JohnVisual Flighthttp://www.visualflight.co.uk

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Thanks for the replies. Yes I was talking about the meshes from Josiah Haut. Anyhow after much deliberation, I've finally decided to order the Visual Flight UK mesh and am very keen to compare the two.Regards, Tony

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Hi Tony.I haven't tried Visual Flight's meshes... I hope you like them. Don't get me wrong about Josiah's meshes. It was an awesome amount of work, and he deserves a big thank you from freeware mesh users. He was quite open about the LOD, source of data, and the process used in the mesh creation. Bravo, for him! His mesh may not have been an increase in accuracy, but it does have a great look to it... just play with the display sliders to minimize the distortion.Meanwhile, the commercial mesh providers seem to be quite mum as to how they produce their meshes, and what the sources of data are.Note:All mesh, commercial or otherwise, must be compiled with the same FS2000 SDK tools. The only differences would be in the topographical data type and source, the altering of that data, and whether multiple INF files ( of different LOD levels ) were used in the compilation.There is no magic to mesh creation, but commercially, there seems to be quite a bit of secrecy. If a commercial provider doesn't list his sources of DEM data, beware... the accuracy is probably no better than Mr. Haut's honest freeware meshes.

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rhumbaflappyIt's one thing for mesh providers in parts of the world where good quality terrain data is freely available to be open about their sources, but in most of Europe the situation is somewhat different. Four months of full-time research, development and testing went into the production of the Visual Flight scenery, which I think puts things into a different perspective.>All mesh, commercial or otherwise, must be compiled with the >same FS2000 SDK tools. The only differences would be in the >topographical data type and source, the altering of that >data, and whether multiple INF files ( of different LOD >levels ) were used in the compilation.In the case of Visual Flight, no data is "altered". All the processing is geared towards making the resultant mesh closer to reality by combining data from different sources, analysing the qualities of the data itself to provide intelligent feedback into the processing algorithms, and by fine tuning the processing parameters to give the best visual representation for the UK/Ireland. Incidentally there are no artificial terrain generation algorithms used - that doesn't fit into the Visual Flight ethos of only working with real data to produce real results.A big difference with the Visual Flight scenery is that we've eliminated the problem of airports sunk into quarries or perched on plateaux, so it's even more unfair in Visual Flight's case to say the only differences are as you describe.>There is no magic to mesh creation, but commercially, there >seems to be quite a bit of secrecy. If a commercial provider >doesn't list his sources of DEM data, beware... the >accuracy is probably no better than Mr. Haut's honest >freeware meshes. There's no need to beware - there are plenty of demos available so you can judge for yourself - there's two from Visual Flight for the Lake District and the Highlands and Islands of Scotland, and Raimondo Taburet also has two available for the UK, so you can get a good picture before deciding between all the available options.The accuracy IS better, both subjectively and objectively. Take a look at the height of the peak of Ben Nevis in the Visual Flight scenery and compare it to real life - the difference is just 18 feet. Then compare it to your freeware mesh which is 363 feet too low. You can repeat the exercise for other hill and mountain peaks.Subjectively, the question of how accurately the landscape itself is represented is a matter of judgement, but I really don't think there's any comparison. I'm quite happy to post comparative screenshots here if anyone wants. BTW I haven't seen any screenshots comparing the freeware scenery to the default yet.Please don't think I'm advertising, but I do think payware scenery producers have a right of reply. I'm quite happy to post comparative screenshots from other payware demos for completeness, and to be fair, I think anyone buying *any* of the more recent payware meshes will notice a big difference from the freeware scenery in most parts of Europe and elsewhere.JohnVisual Flighthttp://www.visualflight.co.uk

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John.If you have "processed" the data, you have altered it.My statement is correct. As consumers, we can only take your word that the combining, altering or massaging of the data is accurate. I'm sure I could come up with small samples of Josiah's work that could be used to attest to it's visual appeal or accuracy. I could come up with testimonials or cryptic references to "special" processes used to produce the Finest of all meshes....I hope your mesh is nice, and I hope the customers are pleased. I'm sure it all looks very good. I have no idea what data sources you used.

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rhumbaflappyI take your point about "altered", although if I were to be pedantic, I could argue that the data sets themselves aren't altered, just used as inputs to derive the desired output.The more important point really is that you don't have to take my word for anything. You can download the demos and assess the accuracy and visual appeal for yourself, but for some reason you seem reluctant to do that.Your skepticism about my description of the Visual Flight processing system is understandable given the nature of some of the claims that have been made for various other mesh sceneries, but there's probably not a lot more I can say to convince you. You're welcome to contact me privately to arrange a visit to see the processing system for yourself if you happen to live close by. (That's not an open invitation to everyone though - strictly a one-off).It's been very good having this dialogue. If you want me to post some screenshots let me know - or maybe I can send you them privately?JohnVisual Flighthttp://www.visualflight.co.uk

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I, for one, would welcome this screenshot comparison.All I want (and I'm sure this is true of all flightsimmers) is for my own back yard to be accurately realistic, I'm not too concerned about what it's like in the next county as long as it's pretty.As I've stated that everyone wants this, it seems it has got to be reasonably accurate everywhere. Tony

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I replaced my FSFreeware(send money).com UK Mesh with the one from Visual Flight because it met my requirements for accuracy.It's a no brainer, really.Starting with the DEM you make sure there's data for the tops of all the mountains, so your data is then "improved". "altered" isn't the word to use here, since that would imply changing the original points.Using other accurate sources, you fill in the gaps. It's not interpolation, it's more like bolstering. It's a good thing!I can produce a 10m DEM of the UK.Here's how,1. Open Photoshop2. Scan map3. Isolate the contour colour, (it's like a brown)4. remove everything else5. assign a color for each 10m elevation.6. Fill in the colors.7. Save as .DEMDone!Who needs NASA and the Space Shuttle?Seriously, it's not as daft as it sounds.Once you've defined the lat/long you have a source which your program reads the RGB value and converts it to an elevation.Bob's your uncle!I'm done! :-)I have a friend who once worked with maps in the Soviet Union. Now, he altered maps!

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Hi Tony.Good point! Accuracy is only a concern for our own back yard. Well put!My sparring with John, from Visual Flight dealt only with the accuracy issue. I, personally would weigh that more from his sources of data, than from a few screen shots or a sample. That's why I pestered him about it. Others may not feel that is important. I like public disclosure, if accuracy is claimed. Otherwise, just say it looks nice and hope somebody buys it.

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I think what Rhumbaflappy wants is just a statement, yes, we included some data from 'whatever' maps to increase the accuracy. I personally think its good practice the let the user know where the data comes from.I think the point not really adressed about downloading demo scenery for payware mesh is how does the user assess the quality? Sure they can give it a go, but how can they test the accuracy if they are not from that region. My earlier post about gaia and my NZ mesh comparison was targeted at the claim from the gaia creators that their mesh was 'very detailed'. It sure had more detail (accurate or not) than the default, but in the end the user had to believe the creators of the gaia mesh that it really is 'VERY detailed'. I think my screenshot comparison showed that the gaia mesh indeed was not very detailed. I think in the end most users want to know the answer to the following question:"How does the mesh compare to reality?"If you don't want to disclose your data sources, you can at least show some real photographs against some screenshots. That way people can really see how 'good' the quality of a mesh is. The standard of a quality of a mesh is not set by the default FS2K2 mesh, but rather by nature (and reality) itself. In the end we are trying to reproduce the existing topograpy of a place, and most users want to know how well a mesh reproduces the existing topography.This post is not meant as an attack, but rather a constructive advice...Ihor, you're completely right with "who needs NASA and spaceshuttle". Most countries have better data anyway, but that data is difficult to get hold of. I'm currently digitising Cook Islands and other offshore New Zealand islands. It really is a nobrainer to add data to GTOPO30 (or even digitise papermaps), but it would be good if the authors would at least say where the data is coming from, ie are the papermaps used 1:1,000,000 or 1:25,000 which is an enormous difference. And if they don't want to, they should show some real photographs as a comparison.Cheers, Christian

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Hi Christian.Yes, you understand my view. A simple public statement would suffice, and some photo comparisons may also help.How can a simmer like Tony, or myself, or you, judge if a commercial source of mesh is going to be a joy for us, or a regret? I can make my own mesh using U.S. government Gtopo30 data. I could interpolate it, or overwork it to a finer LOD level. I could use multiple INF files to "detail" different areas at different LOD levels, to achieve greater undulation in certain areas... But, I cannot get free access to more accurate source data for regions outside the US boundries.Freeware mesh designers are generally being quite open about their source data and how the data was "processed". It would be nice if commercial vendors were as open, especially if they are claiming greater detail or accuracy.As Tony stated, I might not mind if New Zealand mesh had a bit of fantasy in it, as long as it looks good, and the framerates are not overly taxed. It's not my backyard.But you care, because New Zealand is your backyard. And if someone tries to sell you New Zealand mesh, you'd naturally want to know 'how good is it?'. I've tried your mesh, Christian. Not only does it look great, but you've disclosed more than enough info about the source data, to convince me I needn't look anyware else for more accurate scenery. Commercial vendors would do well to emulate your openness, Christian, and I believe they could do so without risk of exposing any trade secrets they may be worrying about.

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Two comments from the above posts stand out for me.>I think anyone buying *any* of the more recent payware meshes will >notice a big difference from the freeware scenery in most parts of >Europe and elsewhere. and> How does the user asses quality?Well, the most realistic scenery I have and still use on FS2002 is Orlando Sotomeyer's Glacier National Park for FS2000. This was free and the readme contained loads of technical data and source material info.I know that it is realistic because I fly around it using a 1:25,000 scale VFR relief map. A solution that anyone can use if they are really interested in an area. The map was downloaded free.I have also flown around a UK Demo of the Scottish islands and without looking at a map I can see glaring omissions of lots of small valleys. Nobody can tell, visually, if a spot height is slightly out but whole valleys, naaaa. These valleys are on the 1:50,000 map so I asume that accuracy is below this level.Also, there are a lot of vertical rock faces (extremely close contours) in the Scottish Isles but the only place that these materialise in the UK demo's is on sea cliffs that actually mostly don't exist.So, for me things haven't improved, mesh-wise, for over two years. This post is not a critisism of anyone's mesh because at least I have had the opportunity to try and not buy.Baz

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BazI think you've taken exactly the right approach - I wish more people would just go out and try the mesh sceneries for themselves. You done that, reached your own conclusions, and that's excellent.I'd just like to comment on a few of the points you made:People in the USA are in the privileged position of having access to freely available high resolution DEM data. The same doesn't apply to the UK, so the comparison with the Glacier National Park Scenery isn't necessarily all that helpful.I appreciate you said "for me things haven't improved" and I guess this is because you're frustrated by the lack of detail at the 1:50,000 level. I fully understand this. We need be be working towards getting this sort of detail, and things are definitely moving forward in that direction. I hope it will be too long before you get a scenery for the UK which meets your expectations.However, things _have_ most definitely improved, mesh-wise, in the UK in the past few years. The latest generation Gaia mesh and Visual Flight mesh _are_ very significantly better than all previous mesh sceneries for the UK, and very significantly better than the current freeware offerings.I won't try and justify these statements, I'd far rather people took Baz's approach and judged for themselves from the downloads and the demos.JohnVisual Flighthttp://www.visualflight.co.uk/

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