GeoControl featured in article.

[monks]

Hello, The Middle Earth DEM Project is in the middle of publishing its workflow. The first part is up and deals with terrain modelling. It features GeoControl a fair bit and how we see it fitting into to what we're doing there.

http://www.me-dem.org/content/view/52/33/

Hope you enjoy, :)

Cheers,
monks

[cajomi]

Very interesting article.
I am thinking about a option to set real world units. The accuracy is internally 32bit, so that is not the problem.

[monks]

Hi Johannes. The lack of real-world units support I think is probably the main distinguishing feature between (for example) Leveller and GeoControl. We recently had an enquiry on the ME-DEM boards regarding GC's real-world units support, so it's clearly important to some users.
There are still a number of features that I've not learned with GeoControl, but I hope that the article gives some insight into the problems and solutions. ;)

Cheers,
monks

[cajomi]

okay, please tell me, in the feature request forum, what do you need! I will see, if I can implement it in the next update.
The brush is done, only documentation must be updated.

[cajomi]

Hope, you do not misunderstand my last post, I meant:
Do you need mostly a correct height, so that the height is real world scale, in the terrain panel.
Or most a working height spam in the project panel, so that there the height is set.
Or a additional dialog for export to terragen, with the settings for grid and so on.

Working with real world scale all over would cause a lot of work, because all filters would have to be rebuild, to take in account the different angles.
So it would be nice, if you would tell me, what the most important you need, so I can add it to this update or to the next, what will definitly be the last change before start of version 2.

[monks]

Thanks Johannes ;)
imo the first priority would be to have the vertical span set in real world units in both the Project and Terrain Panel. For eg, I wanted to use the Project layers to merge the terrain, but it could not work correctly. Also, to have real-world units (vetical and horizontal) in the Terrain Panel would enable more precise modelling.

imo real world units support throughout all of GC would be desirable as a long-term goal. There has been (something of) a shift towards real-world units (and georeferencing). Leveller is now firmly established concerning r-w units support and may even have more support than Wilbur. In our (ME-DEM's) view terrain apps need to move towards GIS-like features (r-w units support, georeferencing, contours, polylines as .shps import/export). I realise though that ME-DEM is a specialised user ;) but TG2 will apparently have more GIS support.:)

monks

[cajomi]

real world units in the terrain panel are not so easy to realize, I would have to change all algorithm, but height span working another way in the projectpanel is realizable for the next update. At time I am doing still a lot of small fixings.

A may be silly question: As far as I know middle earth was drawn flat, not projected on a planet. I really do not understand, how you will project it on a globus, without the typical great! distorsions?

[cajomi]

I have taken a closer look, how to implementate this, and it is not so easy as I thought, even only for the project panel.
This would cause a format change for projects, projectsettings and terrain settings.

So, a format change in the last update is a bad idea. So, no real world heights in version 1, sorry.

I have thought a while about the problem. It is a workaround, and not as good as real world, but you can use the height correction filter in the last level as last filter ,with correction value 100, to adjust the terrain in min and max height.
Only problem is the calculating: You have to calculate for example:
First you have look for the highest terrain, for example 5000 m.
Now 5000 equals 3760 m, and for example 2000m = 3760/5000*2000.
For min the same, if the base height is not zero.
If you now combine the terrains in the projectpanel, keep there the 3760 / 0 setting, and you get correct results.

Sorry, that version 1 will stay without real world units.

Johannes

[monks]

Sorry, that version 1 will stay without real world units.

Ok ,it's no problem.;) In fact I didn't expect it at all, to implement it for version 1! I realise that it must be a major architectural change. For example, World Machine might be also be looking at it in the future but it's not so easy. It uses its own internal 0-1 scale.

The workaround you gave sounds like the approach that I thought about using. It is difficult but it could work.

A may be silly question: As far as I know middle earth was drawn flat, not projected on a planet. I really do not understand, how you will project it on a globus, without the typical great! distorsions?

O-oh- this is a can of worms :lol: I have written many pages on our justification for treating M-E as a globe; we have many discussions on ME-DEM as well.
The root justification is that Tolkien wrote in his letters (it's very well known to those interested more deeply in Tolkien) that M-E was in fact Earth, but at a different time. M-E was a made into a globe before the time that we have maps for (Numenoreans of the early Third Age).
As for tha maps. Well, the whole of Tolkien's creations were presented as not being written by himself, but that he was merely translating them, or presenting them as 'archeological' findings. So, if his maps were not drawn by Tolkien, they were drawn by Bilbo. So, in theory Bilbo could have made errors- indeed his cartographic skill was not that great.
The final hurdle is that Tolkien made sure that the measurements given in the books by the characters (and in narration: ie Bilbo) matched his maps- he checked with a ruler.
There will be some small distortions in our reprojection, though not as great as you might think, because the maps that you and I know from the books only represent a very small proportion of the planet. In fact Tolkien gives us two georeferences in his Letters as Hobbiton = Sarehole (Birmingham) and Florence=Minas Tirith. Therefore you can overlay the maps exactly onto a map of Western Europe.
Also, and this is really hard to swallow, (but this is exactly how Tokkien intended it to be), Bilbo made mistakes, therefore Tolkien made mistakes. Any innacuracies (as long as they are not requiring impossible things such as travelling distances), are absorbed into this 'rationale'.

There is also the notorious objection to a globe that Legolas could not have seen as far as he saw if the Earth was a globe because of the curvature of the Earth. This is incorrect, but you need to go into Tolkien quite deeply. Elves did not preceive the M-E as a globe because they have the Path that is Straight. It's as if the Elves and Men both have different projections in their heads :) flat vs globe.

...you did ask hehe

monks

[cajomi]

my special science interest is meteorologie. I would calculate the radius of the planet by comparing the climatic datas. If the descriptions fit, then the radius might be the same than earth, but I think, there are not so great climatic changes, what would mean, the radius must be greater than earth and so the curvature lower.

But with such a low curvature, I would plan the world flat and project it only in the final overview to a sphere. The distortions are small.

[monks]

That's one, more or less reliable way of approachimg it I guess. As you're interested in meteorology. here's a shot of Middle Earth from space :)
http://www.me-dem.org/component/option,com_zoom/Itemid,32/catid,2/PageNo,9/

The land masses are not necessarily to scale- (they are too large I think) it was just a mock-up. It was done in Fractal Terrains.
Yes, Tolkien regretted his lack of geologic knowledge (though he did have some) and he also regreted his overall strategy of making Middle-Earth. He very much worked his ideas out as he went along. It was only in the later stages of writing and publishing that he realised that he perhaps should have made more of an attempt to get the geology and science, etc correct. I think that his climates may have been incorrect to some extent, but it is categorically known that his intent was M-E to be Earth. So one has to forgive such errors.
The problem was how he worked- he was an extreme revisionist- going back all the time to re-do things. Also another problem was that the surprise enthusiasm (and it's subsequent publication) of the Hobbit, forced his hand. He didn't expect anybody to be interested. After that he was more trapped into standing by things that he had previously said, whereas before the publication, he was not. He did have his 'way out' though: 'I am merely the messanger', and he even changed a couple of details in the original Hobbit in a later print. That's very unusual for fiction!

monks