Help please: massaging topology in Surveyor

parsifal300

New member
Hi All,

I am attempting to lay track next to a water channel in a Miami Florida layout. There are sections where the rails parallel a 20' wide channel. Due to the close proximity of the rails to the channel whenever I attempt to lower the elevation to create the channel it screws up the track elevations. This is especially challenging when the channel and rails are at an angle to the board.

Any ideas on how to prevent track elevation changes and keep the topography looking decent? Any design tips from the experienced would be appreciated.

Thanks
~P
 
I think what you need to do is to apply a vertex height to each spline point along the track first which will effectively set the track elevation at that point and determine the gradient, if any, to adjacent spline points. You should then be able to modify the terrain at will without the track moving. If the track is on a gradient and the spline points cannot all be set to a common elevation, in turn use the Get Vertex Height tool to determine the height of any given spline point, followed directly by the Apply Vertex Height tool to the same point to confirm its height which in turn will set it. Peter
 
You might also use some sort of embankment spline and slide it under the tracks so it hides the jagged edges of the terrain squares. using 5M resolution will aid this even more.

BIll
 
I had attempted to lock in the gradient of the track before dropping the terrain but I got into this chicken-and-egg issue: The terrain would drop below the level of the track so I would attempt to smooth the grade whereupon the channel would fill in.

With your help I found two solutions. Filtering on the work "embankment" with type spline revealed all sorts of assets. I'm using a "river bank" asset if the channel is only on one side, and a double bank that the track can float on if the channel is on both sides.

Thanks for helping with the discovery.

So many assets, so little time ....
 
Happy to have helped. On the top flyout tab (Terrain) there are three buttons at the top which I'm sure you found. If you click the right one, set the dials to minimum size and a small increment, put the mouse pointer near the junctions of each 5 or 10M square. Holding the left button down, drag the mouse forward or backward slowly. The terrain corners will either move up or down slowly, allowing a very fine adjustment of terrain under the track. I only use the track smoothing tool when I am well away from any interference with streams, rivers, or other indentations or embankments.

For urban areas, do a search for items with "retaining" in it (like Retaining Wall). Those will give you great ways to make the track rise from pavement up to an embankment without the "jaggies" you want to cover. It takes practice, but that can be mastered in a short time.

Bill
 
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