Smoothing terrain

[Thai1On]

As work is going well on my route I found I need to fill in a valley from the DEM I made. It is a fictional route based on real topographic maps in on the Kentucky/Virginia border. The problem is I laying tracks where "they should have been" and not using existing grades in this area. Using the tools in surveyor I can "fill " the valley but I want the ground to be smoothed and weathered without steep or pointy spikes. Is there a way to give the ground a smooth/ rolling look?

Dave

 

[mezzoprezzo]

Tidying up the terrain

Two methods I use:


For larger areas lay a long length of temporary track spanning the whole area you wish to “correct”. Place irregularly spaced spline points in between the two ends. Lift and lower the spline points to mould the terrain into the smooth profile shape you want, switchback style. Move the spline points left or right as well. Then fill in the terrain using Smooth spline height button.

Move and adjust the same, or additional, track and repeat as required, then simply delete the track/s.


With smaller spiky peaks/depressions I go into wireframe mode and use the topography Height up and Height down buttons, usually with the radius set to minimum. I find the sensitivity control a bit to fierce when set at anything much more than two stops up, when it tend to make things worse! I also use the Adjust height button a lot with the sensitivity set bit higher because the user has more mouse control.

If your version has alternative wireframe mode (when in wireframe mode press Alt-W) it can be a bit easier to see what is happening. The grid squares become finer and they sub-divide into triangles which hinge across the hypotenuse. It then gives slightly better control over final terrain adjustment.

 

[cascaderailroad]

Please post a screenshot.

Even a high quality DEM can be way off of in excess of +/- 20' in all dirrections (due to high trees and buildings throwing off the terrain heights).

Generally a gradient should be between -2%, and 2% at a maximum steepness.

Most areas will have shallow cuts, where the RR carved the terrain ... or shallow fills, and bridges.

I can tell you from my own personal experience ... While a DEM is a blessing as it creates the terrain for you ... but a DEM can be an absolute nightmare, making an otherwise simple route a massive chore.

Sometimes you just have to fudge terrain by hand in wire frame mode (darkening the time of day to a chocolate color), or using the terrain up/down tool to smooth out inconsistencies.

There are various quality DEM's (1/9th arc, 1/3arc data ... etc ...) some being more accurate than others.

Once you get bill-dings' and twees' on a route, you can hide he flaws in a DEM.

Never pet the sweaty things ... I mean sweat the petty things.

 

[Thai1On]

Good advise and its working. Yes, using sections of rails and smooth spline then moving the track and repeat has filled in the valley as needed. I should add I also used the ground tool or what ever its called to give the ground a random look. Next I used the plateau tool and that seems to "smooth" out the terrain and give it a more rounded look. Weird tool and took a lot of trail and error but seem to have done the trick.

Cascade you're right. Once I add ground textures, trees and stuff most of the problems will disappear. Besides if I keep trying to tweak the ground into being perfect I'll never finish this monster.

Dave