topic Re: Mesh over site plan in Modeling

Mesh over site plan

Tom Krowka — Thu, 25 May 2023 15:09:31 GMT

Need to create a site mesh on a plan that has quite a bit a vertical of change on a five acre piece of property. What is the most effiecient way to do this. Am not interested in purchasing Architerra.

Re: Mesh over site plan

Anonymous — Wed, 10 Dec 2008 22:41:46 GMT

make a mesh of the boundary shape

then space click the contour lines with the mesh tool on
hit "fit to user ridges" each time the dialog box come up as you do this

then with the mesh selected click each of the contour lines and change the Z values to suit (tick the "apply to all " box each time)

then set the heights for the corners to suit.

Re: Mesh over site plan

Anonymous — Wed, 10 Dec 2008 22:43:05 GMT

theres a detailed how to here under "tips and tricks"

u might need to redgister on the site to view it tho

http://archicadselect.com/

Re: Mesh over site plan

Tom Krowka — Fri, 12 Dec 2008 21:32:43 GMT

Would that be "quick tip 2006#2, Stamping meshes". That seems to be the only one I can find that relates at all to this process.
Tried your short method.....doesn't seem to work quite the same. Do the contour lines have to be contained within the mesh boundary?

Re: Mesh over site plan

Thomas Holm — Fri, 12 Dec 2008 21:51:13 GMT

http://www.archicadwiki.com/TechNotes/Handle%20huge%20surveyors%27%20drawings?highlight=%28CategoryJapanese%29

Re: Mesh over site plan

Karl Ottenstein — Sat, 13 Dec 2008 00:06:50 GMT

GeNOS wrote:
make a mesh of the boundary shape

then space click the contour lines with the mesh tool on

Tom,

I have yet to encounter a survey dwg in the US (Tom's question) that allows magic wanding of the contours because of (1) the major contours are not continuous - breaks for in-line elevation annotation and (2) the contours have way too many points, and magic wanding adds all of that unnecessary data to the mesh, adding too many polygons.

In my experience, tracing over the contours (snapping at reasonable points) is fastest and gives the 'fastest' (low polygon) mesh. I'd trace pretty precisely and include minor contours at the actual building site in your 5 acre parcel - and do just major contours and somewhat looser contour hugging for the rest of the lot.

Generally, I trace over with polylines and then magic wand them (again, because I have yet to receive continous surveyor contours).

Sounds like in the lands down under they get better files than I've seen here... 😉

Karl

PS The article that Thomas links to is useful for magic wand settings, etc.

Re: Mesh over site plan

Karl Ottenstein — Sat, 13 Dec 2008 00:14:47 GMT

I see Roberto's Italian survey had continuous contour lines as well... so I'm posting what I have found to be typical, at least in the mountain west of the US. Notice that the major contours (red) are broken to display the elevation text inline. This is not a masking thing. There really is no line there - so you have to recreate a continuous contour that spans the text to get the mesh ridge entered properly.

Is this what other people in the US see as well? I've assumed this is how all US Civils are trained...but maybe it is a local thing...

Cheers,
Karl

Re: Mesh over site plan

vfrontiers — Sat, 13 Dec 2008 00:51:30 GMT

Same here Karl.... It's a bummer to have to FILL IN these little lines.

Re: Mesh over site plan

Anonymous — Sat, 13 Dec 2008 00:53:04 GMT

Hello Karl,
This is what I have seen here in the Northeast.
I understand that many surveyors use the same
cad application to produce their site survey drawings
as a DXF or a DWG file.
I don't remember if the last hand drawn survey I saw
used this convention but I have seen survey drawings
done by architects that had no break in the contour line
and the elevation text was only at the ends of the contour line.
Peter Devlin

Re: Mesh over site plan

Dwight — Sat, 13 Dec 2008 01:10:43 GMT

The key is that the Archicad operator must, as Karl observes, cleverly build the mesh from extrapolated contours to minimize polygons in unimportant areas and carefully place nodes in critical areas to best model the true slope.

A blind reliance on tracing the contour plan guarantees an excessively high polygon count and creation of artificial horizontality in a situation that does not possess it.

Re: Mesh over site plan

Brett Brown — Sat, 13 Dec 2008 10:14:30 GMT

Tom wrote:
Would that be "quick tip 2006#2, Stamping meshes".

Tom, the tip sheet is 31/5/2007 "Site Modeling" , could be helpful in explaining the process.

Re: Mesh over site plan

rocorona — Sat, 13 Dec 2008 13:52:02 GMT

Karl wrote:
... Notice that the major contours (red) are broken to display the elevation text inline. [...]

Is this what other people in the US see as well? I've assumed this is how all US Civils are trained...but maybe it is a local thing...

Only when representing a "small" piece of land, the lines are continuous, with the numbers written only on one or both ends. For large maps, here too the numbers are in some points (one or more, depending on the drawing size) inside the major lines.

And yes, I fully agree that the points wisely chosen by the user are far more efficient than any automatic procedure!

Re: Mesh over site plan

Anonymous — Sat, 13 Dec 2008 17:23:57 GMT

Karl wrote:
I see Roberto's Italian survey had continuous contour lines as well... so I'm posting what I have found to be typical, at least in the mountain west of the US. Notice that the major contours (red) are broken to display the elevation text inline. This is not a masking thing. There really is no line there - so you have to recreate a continuous contour that spans the text to get the mesh ridge entered properly.

Is this what other people in the US see as well? I've assumed this is how all US Civils are trained...but maybe it is a local thing...

Cheers,
Karl

Yup, the broken main contours seems to be typical practice in the US. Sometimes I just punt and leave them broken. It means more spacebar clicks and elevation adjustments but that's often easier than tracing over it all. But then some of the DWGs are thousands of tiny line segments and then there's no choice but to trace. All depends on the situation.

Re: Mesh over site plan

Link — Sat, 13 Dec 2008 21:39:55 GMT

I've found that usually you can just insert a line to bridge the gap(s) and then magic wand the contour quite successfully. But sometimes even the individual lines that make up the contour can overlap by a tiny amount making the whole process very frustrating indeed.

it would be nice to understand why that happens.

Cheers,
Link.

Re: Mesh over site plan

David Maudlin — Sun, 14 Dec 2008 14:58:47 GMT

Matthew wrote:
Yup, the broken main contours seems to be typical practice in the US. Sometimes I just punt and leave them broken. It means more spacebar clicks and elevation adjustments but that's often easier than tracing over it all. But then some of the DWGs are thousands of tiny line segments and then there's no choice but to trace. All depends on the situation.

Link wrote:
But sometimes even the individual lines that make up the contour can overlap by a tiny amount making the whole process very frustrating indeed.

Is it possible to select all the lines in one contour and use the Intersect command to have them all join properly? Just a thought.

David

Re: Mesh over site plan

Anonymous — Sun, 14 Dec 2008 22:43:46 GMT

i usually just open the survey in auto cad. remove everything i dont need, keeping only the boundary and the contours. then make sure the contours are all continuous (removing the elevation text etc...) and triming them to the boundary.
from that i make my mesh in the steps from my 1st reply

Re: Mesh over site plan

Link — Sun, 14 Dec 2008 23:01:32 GMT

David wrote:
Is it possible to select all the lines in one contour and use the Intersect command to have them all join properly? Just a thought.

That's a good thought David - can't say I've tried it, but it should work for most cases I would say.

GeNOS wrote:
i usually just open the survey in auto cad.

Why do in AutoCAD what you can do in ArchiCAD? Seems like an antiquated approach to me.

Cheers,
Link.

Re: Mesh over site plan

Anonymous — Sun, 14 Dec 2008 23:14:51 GMT

the survey is an autocad drawings.. autocad has better 2d tools to get it done quicker. i find the 2d side of archicad pitiful.. but i have only been using it for 4-5 months, so maybe im missing something

Re: Mesh over site plan

Karl Ottenstein — Sun, 14 Dec 2008 23:19:44 GMT

Link wrote:
David wrote:
Is it possible to select all the lines in one contour and use the Intersect command to have them all join properly? Just a thought.
That's a good thought David - can't say I've tried it, but it should work for most cases I would say.

Well, maybe if it was easier to select the contour lines than in the files I get.

See attached screenshot. Arrows point to the inline elevations of a single contour and the grouping dots are a few of the random line segments that I selected. If the dwg converter could magically join the hundreds of short segments into a single polyline, then David's idea might work... but just too much work here.

Karl

Re: Mesh over site plan

Anonymous — Mon, 15 Dec 2008 19:49:53 GMT

Karl wrote:
Notice that the major contours (red) are broken to display the elevation text inline. This is not a masking thing. There really is no line there - so you have to recreate a continuous contour that spans the text to get the mesh ridge entered properly.

I used to fill in the gaps, but more recently, I've found that leaving the gap there and having two seperate non-continuous contour lines made no depreciable difference.