Wishes
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Linework simplification

Anonymous
Not applicable
I have some topography lines that I want to convert into a site mesh. The problem is that they are way too segmented. I tried using the linework consolidation tool, but what I would have drawn with a single line manually exists as a series of segments barely different in angle. Short of redrawing every contour line, does any one know of an existing method for simplifying this?

It would be nice if you could enter a minimum angle and then ArchiCAD would go through the polyline:
if (angle ABC is less or equal to the minimum angle)
then (delete segments AB and BC. add segment AC. repeat for AC and the next segment)
else (repeat for BC and next segment)

This would work well as an option in the linework consolidation tool.

pardon my pseudo-programming
18 REPLIES 18
Chazz
Enthusiast
Mr (or Ms.) Dmn, I agree that that deviation angle would be an effective and welcome option of the magic wand. There is a wiki article on this exact contour line problem and I would have even searched for the link if you had included a sig in your post --as is the custom 'round these parts. A name and a city is also appreciated by us curious folk.

welcome aboard.
Nattering nabob of negativism
2023 MBP M2 Max 32GM. MaxOS-Current
Thomas Holm
Booster
dmn wrote:
I have some topography lines that I want to convert into a site mesh. The problem is that they are way too segmented.
A number of tips on this subject:
http://archicad-talk.graphisoft.com/viewtopic.php?p=105587#105587
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1
Anonymous
Not applicable
Thomas wrote:
dmn wrote:
I have some topography lines that I want to convert into a site mesh. The problem is that they are way too segmented.
A number of tips on this subject:
http://archicad-talk.graphisoft.com/viewtopic.php?p=105587#105587
Thank you.
Anonymous
Not applicable
On second thought, it doesn't solve my problem. I thought the method in the ArchiCADwiki link would work, but if you're not careful, or if the terrain is complex, it results in overlapping lines. It really needs to be according to angle. So my request stands.
Anonymous
Not applicable
mmm, and if the script could also limit placing a new segment by detecting wether or not it's overlapping another segment (checking against the adjacent contours) that would be even better
Chazz
Enthusiast
dmn wrote:
mmm, and if the script could also limit placing a new segment by detecting wether or not it's overlapping another segment (checking against the adjacent contours) that would be even better
It could be that taking a completely different approach is the answer, nice though the angle segment tweak might be to the magic want tool. What about using Architerra. I haven't used it in ages but it seemed to be moving in the direction you would like.
Nattering nabob of negativism
2023 MBP M2 Max 32GM. MaxOS-Current
Dwight
Newcomer
Whenever the discussion of contour lines being difficult to manage or that contour lines create too many mesh nodes, I fell obliged to recommend a simplified method of terrain modeling that takes only a few minutes and speeds 3D imaging.

Contour lines are abstracted interpolations from samples. This data is converted into what is supposed to be a horizontal slice through a site. When we model a site, we seek to conform our model to the true shape of the site, but the contours are simple interpolations of this data and can't be totally accurate.

My method of site modeling is to create an adaptive grid. It is adaptive because the grids get smaller in steep or complex areas and larger in flatter areas. You place this grid over the site plan and add mesh nodes elevated to match the nearest contour height. Prominent outcroppings get higher detail.

This method creates a plausible site form with a fraction of the nodes, but in doing one, you must be aware of the general location of building areas.
If you do have an idea of the building plots, you can level these areas as you work.
Dwight Atkinson
TomWaltz
Participant
why not just turn down the resolution on your magic wand?
Tom Waltz
Thomas Holm
Booster
Dwight wrote:
My method of site modeling is to create an adaptive grid. It is adaptive because the grids get smaller in steep or complex areas and larger in flatter areas. You place this grid over the site plan and add mesh nodes elevated to match the nearest contour height. Prominent outcroppings get higher detail..
Dwight, could you please link to (or write a brief tutorial on how to do this? Or perhaps just an exampla of an adaptive grid in plan view?
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1