Large-scale terrain modification. Advice needed.

[Rockdoc2174]

To help with the Friargate Line I'm trying to learn how to lay assets, particularly roads, as realistically as I can. I live in Oakwood, on the edge of Derby, and I drive through Breadsall quite often so it seemed like a good place to begin as I know it quite well. Brookside Road has a varying downhill gradient from its junction with the Derby-Heanor road (A608) and I struggled to get the terrain to match the gradient until Brian Yeomans made a suggestion that cracked that one. However, I've now hit a major snag and I have no real idea how to get round it and keep the scenery looking realistic.

Beyond a row of bungalows and houses the road falls steeply to the valley floor and then falls only gently through the village itself. The terrain DEM data works well enough up to the end of the buildings but it appears that the DEM has subsequently taken the heights of trees in heavily-wooded areas and used that as the datum instead of the land surface. The result is I can make the road reach the valley floor at the right point and gradient but, instead of rolling countryside to my right and the valley into which the village sits in front of me, I face a 10m cliff.

How on earth can I lower and re-shape very large areas of terrain and keep things looking sensible?

Keith

[Pauls]

Sorry I don't have an answer for you - I have the same problem in areas of my Charnwood Forest Railway route - so I await THE answer with interest !

I was considering laying a OS Map decal that showed contours and laying track along the contours and then setting the track at the correct height for the contour and snapping the terrain to it - but this sounds too clumsy ? - you probably already know that you can set terrain to a specific height with the World Editor tools ? - I sort of need a tool that would change the height of the terrain by a given amount - say minus or plus 25 ft rather than for all the terrain to go to a specific height - say 300 feet which forms a flat plateau where you use that tool. Perhaps you could lay a OS contour decal then run the terrain height tool along each contour with the height of the contour set ??

Hopefully one of the route building guru's will give us a very cunning answer !!??

Cheers
Paul

[Stone75]

If your road as in the right place, can you snap terrain to the road level leaving you a trench with the road in it, then use smooth terrain on a broad brush size to get common heights. Probably repeat again as the road becomes covered and follow with your own touches.

Stephen.

[Rockdoc2174]

Although roads have much in common with tracks and use track rules, not all of the track tools can be used on them. I'm getting the road level and gradient right by laying a track to the road's track rule, snapping the terrain to that and then replacing the track with a road. I guess I could lay many such lines of track to lower the terrain more widely but I think there's a risk it would look too uniform.

Keith

[Stone75]

Aye did not realise roads don't snap too, sorry about that. I still think the smooth tool will help you though. I usually drop the level of the area with quite a broad brush depending on size of the valley. Then with a very broad smooth tool, run it over the edge of the area brining surrounding terrain into line with the contours. I think trial and error on settings but I do love the smooth tool for making contours. I know not much help but good luck getting it done.

Stephen

[Nobkins]

Steve is right in the post above. By playing around with the values for the various terrain height adjustments and particularly the smooth tools you can achieve a good similarity with real life although it is by no means easy.

Although, as a route builder my self, I know it is hard to settle for something you know is not 100% accurate. I have found it one of the hardest lessons to learn that the game is not capable (particularly with the terrain grid of 8m x 8m) of that level of accuracy. Sometimes a close match is great and perfection has to remain elusive.

Hope that does not sound discouraging. Not meant to be just trying to help pass on something that took me a long time to learn and still I often forget to put into practice.

Cheers

Jim

[longbow]

I assume you are using the Panorama DEM data from this site? It's much more accurate than other DEM sources.

Large scale OS Maps often show road spot heights as of course will points where the road crosses a contour line.

[Rockdoc2174]

Thanks to everyone. I have no idea what data Chris Baker has used for the route. I'm just playing with his baby! I'm using the Google Earth overlay to give me a decent approximation to the position of the roads, which have changed in places in the last 60 years as you'd expect. I'm also using period OS maps for height benchmarks, as longbow suggests.

I have tried using larger nets and so on, as Steve suggested, and it does help a lot. I'm much happier with what I can do now, though it's still likely to be quite a long slog just for one of the small villages along the route. Finding the limits of the Editor is part of this exercise for me. I need to discover what I can and can't do and what's worth the effort and what isn't. There's clearly little point in spending a lot of time on something that's a mile or more away, for example.

I don't yet feel either competent or confident enough to do this "for real" so I'm experimenting on the last version of the route I have and not worrying too much if I make a Horlicks of it. I can always reinstall it if it gets too bad and the more of this I do the quicker I'll be able to get it done when Chris is ready for me to get stuck in.

Two more questions:
At the moment I'm working close to the line and trying to put in the things that have to be put in to give it atmosphere while driving. How far from the line should we be looking to do some degree of scenic modelling to cover the helicopter (Key 7) view?
What sort of distances from the line can we start to use lower-poly models and scenery flats? From looking at the scenery while driving my car, my gut feeling is that 100-200 yards is enough to lose a lot of the impression of depth on a building so simple assets would be ample and flats could be used from half a mile away or perhaps a little more.

Thanks again,
Keith