Author Topic: Surface Cross-Section problem  (Read 320 times)

pinbot

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Surface Cross-Section problem
« on: December 20, 2019, 04:11:06 PM »
Hello Lars and friends!
As a land surveyour I use many CADTools commands and simply love it! ;)
I'm trying to set workflow for bridge rehabilitation projects, and have few questions and problems.

Right now my workflow looks something like this:

1. I survey road with total station in intervals 5-10m which include; left and right bridge edge, curb, travelway, left, right and middle line
2. In Autocad I connect all this points with 3dpolylines
3. I make CADTools surface from mentioned 3dpolylines, and use them as breaklines.
Then I inspect surface to correct any inconsistencies, and save surface again.
4. I use middle line as alignment, and create longitudinal profile by using Profile 3d polyline
5. I make Surface Cross-Section and now things complicates little bit.
When I look at surface in plan view, it looks as it should, but when I make surface profile, it interpolates crossections, and I get something really weird (screenshot below), so they are useless. I added Reference lines (RED polyline) to profiles, so you can see how profile should look like, and surface (YELLOW polyline).
Am I missing something, or doing something wrong?
Would it be possible to crossection just 3dpolylines, to completely avoid surface?

Lars

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Re: Surface Cross-Section problem
« Reply #1 on: December 21, 2019, 09:29:19 AM »
Hi,

I think you get a better triangulation if you survey lines along the bridge not cross the bridge.

As for now you can try to clean up the input data. Use the CadTools Simplify command with a tolerance of zero to remove vertices that isnít contributing to accuracy and only will generate extra triangles.

When triangulating use all lines as breaklines and remember that breaklines is not allowed to cross.

As for the curb lines, triangulating points (vertex) with same coordinates but different elevation is not allowed. You have to supply lines that is will try to create vertical triangles. However you can offset one of the lines horizontally a very small distance to avoid that scenario.

pinbot

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Re: Surface Cross-Section problem
« Reply #2 on: December 23, 2019, 04:14:11 PM »
Thank you for all suggestions, but simplify process didn't work. I get same scattered crossections :'(

I survey along the bridge stopping at every station, and survey characteristic points left and right, and I get pretty nice bridge/road 3d model, but problem is that I can't make usable crossections  :(
Since I generally have 30+ sections, I do alot of manual work. I'm trying to simplify some steps, and maybe you could help with little bit of CT modifications.
If it would be possible to drape crosslines/polylines to surveyed (and connected) longitudinal 3dpolylines, instead to a surface (which scatter sections), I would get precise crossections.
I could then use ''Surface Cross-Sections'', or maybe you could modify ''Profile 3d polyline'' a bit, so you can select multiple 3d polylines and profile them. Modification of ''Profile 3d polyline'' would be great, because it has height, distances, slopes and height differences, which is very very usable. I red whole forum, and I saw that I'm not the only one who would benefit from such modifications, so I hope you can spare little bit of your free time to help.

Thanks in advance!

Lars

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Re: Surface Cross-Section problem
« Reply #3 on: December 24, 2019, 01:31:31 PM »
I'll check if there is something wrong in the code for creating cross section.
What version do you use (Build)

/Lars
« Last Edit: December 24, 2019, 02:49:26 PM by Lars »

pinbot

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Re: Surface Cross-Section problem
« Reply #4 on: December 25, 2019, 12:37:23 AM »
Version 730
Merry Christmas! :)

ish0000

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Re: Surface Cross-Section problem
« Reply #5 on: December 25, 2019, 09:15:25 AM »
I am also waiting for cross section (option) from 3d polyline. before i also upload image for that.
would it be possible to cross section just 3dpolylines, to completely avoid surface?

thanks

Lars

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Re: Surface Cross-Section problem
« Reply #6 on: December 26, 2019, 03:27:07 PM »
I've refined some of the codebase involved in creating cross sections. Hope this will work better.

As for cross section from 3DPolylines you have to create a surface based on your 3Dpolylines.
However you can populate your cross sections with 3D lines from current drawing. In the cross sections you may add all your 3Dpolylines as Display Reference lines (plan lines). When you plot your cross sections all reference lines will be placed on same layer as they have in current drawing.

pinbot

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Re: Surface Cross-Section problem
« Reply #7 on: January 07, 2020, 05:03:22 PM »
I've refined some of the codebase involved in creating cross sections. Hope this will work better.

As for cross section from 3DPolylines you have to create a surface based on your 3Dpolylines.
However you can populate your cross sections with 3D lines from current drawing. In the cross sections you may add all your 3Dpolylines as Display Reference lines (plan lines). When you plot your cross sections all reference lines will be placed on same layer as they have in current drawing.

Dear Lars, thank you for investing your time in resolving the issue, but I still can't get usable crossections, surface doesn't represent road as it should. I use dummy surface and add display references to section them. Problem is still alot of manual work, I need to connect all little circles in crossections with polylines, and align text to the bottom (band). It would be helpful atleast if there were command to connect circles with polyline according to X axis.

Lars

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Re: Surface Cross-Section problem
« Reply #8 on: January 07, 2020, 06:30:40 PM »
Plot your cross-sections as real 3D sections (with a short distance), then use orbit to get a good view and then connect your curbs or other points with a 3Dpolyline. Finally use them as breaklines in a new triangulation. You may also filter your survey points of interest and connect them.
« Last Edit: January 08, 2020, 06:55:24 AM by Lars »