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Question

Contour generator - problem with breakline

  • May 10, 2022
  • 5 replies
  • 69 views
B

Hi guys,

 

I have DTM files in ASCII GRID format and I need to generate contours from this files. Everything works fine untill last step.

 

When I am generating contours with contours generator transformer everything works fine, but I have in the area few lakes where I don't want to generate contours.

 

I've tried to use breaklines but when I am using it generally nothing change - contours still looks the same.

 

I have layer with lakes where I don't want to generate contours. Before connect it to Breaklines arrow in ContourGenerator transformer I am using geometry coercer and 3DForcer.

 

Can you guys tell me what I am doing wrong? I have no idea how to manage with this.

 

Screnshot below. Brown polygon is a lake.

 

Thank in advance.

 

5 replies

redgeographics
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  • redgeographicsCelebrity
  • Celebrity
  • 3699 replies
  • May 10, 2022

I don't think you're doing anything wrong per se, it's just how the DTM interpolation works. What you can try is using a Clipper to remove the contours that fall inside the lakes.

FME rocks! \m/
B
  • bukakalke
  • Author
  • 3 replies
  • May 10, 2022

I don't think you're doing anything wrong per se, it's just how the DTM interpolation works. What you can try is using a Clipper to remove the contours that fall inside the lakes.

Thanks for your answer. Is there any chance to remove also two nearest contours generated out of this brown polygon?

B
  • bukakalke
  • Author
  • 3 replies
  • May 10, 2022

I don't think you're doing anything wrong per se, it's just how the DTM interpolation works. What you can try is using a Clipper to remove the contours that fall inside the lakes.

Generally what I want to do is generate contours but I don't want to get them (contours) in lakes/rivers areas and contours located on the edge of this lakes/rivers.

M
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  • markatsafe
  • 1891 replies
  • May 10, 2022

@bukakalke​ Have you tried experimenting with the Surface Tolerance? If you have the lake polygon, try adding that as a breakline (if you knw the Z value).

B
  • bukakalke
  • Author
  • 3 replies
  • May 10, 2022

@bukakalke​ Have you tried experimenting with the Surface Tolerance? If you have the lake polygon, try adding that as a breakline (if you knw the Z value).

@Mark Stoakes​ Hey! I added lake polygon as a breakline and I added Z value with 3DForcer - you can see result on attached screenshot.

I've tried with surface tollerance like 0.5, 1, 2 etc. but nothing change...


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