topic Re: How to mask or exclude everything outside the contour line shapes. in ArcGIS Mapping and Charting Questions

How to mask or exclude everything outside the contour line shapes.

RickCheney — Fri, 30 Dec 2016 16:34:31 GMT

The images below are kind of crude but I hope they help explain what I am trying to accomplish. The blue background is a TIN and the star shapes are from a shapefile with contour lines. How can I get the TIN to only show the data inside the contour lines? Do I mask the TIN or re-create the TIN? Or, extract by mask? The contour lines represent lake depths and there are actually many more lines within the shapes/lakes. The TIN shows the depths which are negative. The blue area outside the shapes is identified as having a depth of -5 so that area might be lowland or swamp or something but I want to exclude it from the TIN. If I try to change the color of any area that is -5 then I loose the color inside the shapes as well as outside the shapes.

what it looks like now above and what I want it to look like below

Re: How to mask or exclude everything outside the contour line shapes.

JayantaPoddar — Fri, 30 Dec 2016 17:36:23 GMT

Are the contours, closed lines. Then you could convert lines to polygons.

Then do a Copy TIN followed by Edit TIN (Hard_Clip).

(Doing a Copy TIN, since Edit TIN makes changes in the input TIN data)

Re: How to mask or exclude everything outside the contour line shapes.

RickCheney — Fri, 30 Dec 2016 18:33:45 GMT

I should have included screen shots of the contour lines. Most are closed but a few are open. I should have mentioned that there are two layers, one with the contour lines and another that is a TIN which show the depth inside of the contour lines. Converting the contour areas to polygon removes the depth data.

Maybe my question should be, how can I clip or re-create the TIN so that the TIN only shows the area within the contours. Maybe this is happening because some of the contour lines are not closed? If that is the problem, is it possible to edit the contours to "close" some of the lines?