keithhe

What Is Chief Doing To Terrain?

Recommended Posts

This terrain has proven difficult. I thought having the DWG for it would have made things easier, but not the case.

Can anyone explain what CA is seeing that I can't in its interpolation of this terrain? Specifically the rows of divets (very deep) it is adding automatically and nothing I can do to get rid of them. Nothing I've seen on a terrain before. See attached photo and plan.

Suggestions to "smooth" this terrain while keeping the overall slope nature of the lot?

Thanks,

Keith

post-489-0-27757700-1450413565_thumb.jpg

Costa Rica Test.plan

Share this post


Link to post
Share on other sites

Thanks Mark !! That looks a lot smoother.

I'm of the opinion that too much elevation data lines in CA just messes things up. Just always too choppy I find, but curiously sometimes I have fairly busy terrains with quite a few elevation lines that look fine, and smooth. If I can just figure out the right combination of elevation data and other parameters to make them all work.

Share this post


Link to post
Share on other sites

Less elevation data will always produce a smoother terrain.  Also consider some small (strategically placed) elevation regions which will tend to make smoother transitions from level to sloped areas.

Share this post


Link to post
Share on other sites

Thanks Joe. I'll do some strategic removal of elevation lines, as Mark did, which looks pretty good, and see what I can get. I think I will keep the lines, as non-elevation though, for any site work later, but not to generate terrain. Less is better.

Share this post


Link to post
Share on other sites

There is some errant elevation data in the plan that I can't easily find.

 

I copied the elevation lines into a new plan, and everything looks good.

post-62-0-00579000-1450418533_thumb.jpg

post-62-0-10364300-1450419096_thumb.jpg

Share this post


Link to post
Share on other sites

Bill, you did this without removing any lines? From what I can see of the thumbnail, that looks great. Can you explain how you did that?

Share this post


Link to post
Share on other sites

Here it is with no lines removed.  I may have missed a few lines.  It was my goal to avoid the gremlins.  There is some un-selectable elevation data that is affecting the topography; causing the divots.

 

post-62-0-20824300-1450421463_thumb.jpg

Share this post


Link to post
Share on other sites

Bill,

I thought that some of the CAD import data may have been wrong, and checked lines in and around the divots (primarily the secondary contours) and could not find anything inconsistent with what should have been there. No other elevation data brought in, so no idea where the divots are coming from, although you got rid of them. Still not sure what you did ??

Share this post


Link to post
Share on other sites

I'm not sure what I did, but it works.

 

I thought it was errant elevation data, but now I don't think that is the case.

 

I've done larger properties with steeper slopes without problem.  I usually use two foot contours, but will sometimes use five or even ten foot contours with larger properties.

 

There are some minor divots in this plan, but it's behaving much better that the original plan.  I notice it behaves much better when I use fewer contours although this plan has all of the contours active. 

metric topo 2.plan

post-62-0-04271200-1450427815_thumb.jpg

Share this post


Link to post
Share on other sites

Thanks Bill !! No idea how you did this, as I could never get the oddities out of it. I have found that terrain is one of those difficult to understand features of CA, if you are trying to get a real world situation correct. Some of the things just don't do what you would expect. Must be a cake walk for the flatlanders. :)

Share this post


Link to post
Share on other sites

Just wanted to thank the guys that helped with this (Mark, Joe and Bill). Lots of good answers, so hard to pick anyone "best", as all helped.

Share this post


Link to post
Share on other sites

Keith,

You have several Elevation Regions that are causing most of the problems.

There is one main culprit in the top left corner of the site and several down in the lower left.

 

The easiest way to delete them all is to select one, click the Match Properties tool, check Object Type (make sure it is an Elevation Region), OK.

This will select all (well, most of them) the Elevation Regions in the plan, hit Delete.

Rebuild the terrain.

 

There are other weird things going on with the plan as well - but the above is the main cause of your problems.

 

Here is a video:

 

http://screencast.com/t/IiVcGgbeI

Share this post


Link to post
Share on other sites

Glenn,

 

Curious as to how this may have happened. I added no terrain regions, and simply imported the CAD DWG that as far as I could tell only had the contour lines and the terrain perimeter. The rest, was I though text file related. I will go back and try what you say, but would never have occurred to me that somehow terrain "features" or regions were there. Great catch, and has me curious to figure out where it was coming from. 

 

Thank you sir, as this was really frustrating to see the odd things happening that normal interpolation between elevation lines should not have caused.

Share this post


Link to post
Share on other sites

Keith,

 

The Elevation Regions were probably created automatically from closed polylines (contours).

That's all an Elevation Region is - a closed Elevation Line.

 

If you draw an closed Elevation Line (polyline) and open it's dbx, it is actually the Elevation Region dbx that opens - not the Elevation Line dbx.  

Share this post


Link to post
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now

  • Member Statistics

    27612
    Total Members
    6254
    Most Online
    kBdesignND
    Newest Member
    kBdesignND
    Joined