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Site model from topo data


burgcj

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Hi all,

 

Does anyone know if it's possible to create a site model from the topo data I have, all of the tutorials I have watched have had contours across the whole document, mine doesn't appear to have as many. I may well be reading it wrong, as it's the first time i've tried to do this. The document does contain plenty of elevation info as text and 2d shape but there doesn't appear to be any contour lines throughout the entire document as I've seen with others. The only contour lines is has are for either side of the 'track', top/bottom edges and the dry stone walls surrounding. I've attached a series of images of parts of the topo to give an overview.

 

Images

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It looks like you need to do some pre-processing to get this to work.  Note, I am not a DTM (Digital Terrain Model) expert, so others may give you much better information.

 

In my understanding, it does not look like the drawing you have has data in a format that the DTM can use.  It appears to have the information you need, but not in the right format.

 

The little crosses are locus points, but they are 2D.  Next to each locus point is a block of text that appears to be the elevation at that point.

 

What you need are 3D locus points with the Z position of the locus set to the value of the text. 

 

If you can, I would go back to whoever generated the drawing and ask for a spreadhsheet of the locations with X/Y/Z coordinates. There is a command to import this data and generate 3D loci that can then be used to make a DTM.

 

The alternative is a long day of manually placing a 3D loci at the point of each 2D loci and manually changing the Z Value. I recommend you do this on a separate layer with Show/Snap layer options.

 

I thought there was a script at one time that tried to look at local text and apply that as a Z value, but I can't find it.

 

Good Luck.

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Hi all,

 

Sorry for the delayed reply, I've been occupied with drawing bridal gates and stiles before I can get back to this model!

 

All of the info/options you've provided look spot on, I'll have a look through all of the various links and also try to go back to the topo contractor for the spreadsheet of info as I'd like to try both methods if I can.

 

In case anyone is interested, the topo data is of a Byway (BW) which i'm tasked with repairing/ resurfacing and installing sufficient drainage (working with drainage team) to mitigate the water erosion and damaged caused by 4x4 vehicles. I've floated the idea of bringing the levels back up on the BW to a similar gradient as the natural slope of the hillside to allow the water to run off in the direction it would have prior to someone bench cutting a big track down the middle of it.

 

Thanks again for all of the great advice, i'm sure i'll be back with another question regarding 3D modelling existing terrain and layering proposed improvements clearly.

 

Cheers

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This is what i'm getting, you can just about make out the track that cuts through the land. most of the data is supposed to represent drystone walls and verges that i'm not quite getting.

 

I ran the data validation and removed duplicate points. It seems to want me to have my lower elevation set at 0.

 

Not sure why i'm getting the spikes in the bottom left either!

 

Any help would be greatly apprecaited. Happy to attach a file

Terrain snip.png

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Also you might want to add some of your own points around the perimeter to fill in the gaps where the survey data is absent, so that the site model isn't spanning the outermost points + creating unnaturally stretched areas between them (probably could be explaining this better).

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  • 1 year later...
On 1/25/2023 at 9:13 PM, Tony Kostreski said:

Hi @burgcj,

You can certainly place stake objects manually if there aren't too many but if you want more of an automated way you could use a marionette script as @Nico_besuggested. It looks like you have an object representing a spot elevation (x) and a text value next to it. The following Marionette is quite valuable to automatically place a 3d loci on the (x) marker and use the text value for it's "z" parameter.

 

Instructions:

  1. Use "Test Proximity" to make sure the text value is pointing to the right marker (x)
  2. Use "Text to 3D Loci" for placing a 3d loci on the marker (x). The "z" value will automatically use the text value pointing to it.

 

I covered this in a webinar https://university.vectorworks.net/course/view.php?id=2434  you can fast-forward to 22:30

 

 

 

When I run this i get lines all over the over 80 meters apart, is there a way to reduce the distance between text and level point to say 1 meter ?

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1 hour ago, Stu Wilson said:

 

 

When I run this i get lines all over the over 80 meters apart, is there a way to reduce the distance between text and level point to say 1 meter ?

All sorted... numbers of points and text didn't match

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  • 1 month later...

Wouldn't it be nice if VW just imported a DTM surface that was already created and in a CAD file like every other CAD package? Rather than badly recreating a site model from points.

 

I'm a surveyor and it baffles me that VW can't just import an already created surface with 3D faces from a CAD file like a DWG DXF or LandXML. (Please point me in the right direction if they can)

 

When I do a survey, I make a surface that is the best representation of the existing site using spot levels and break lines. I know that you can create a terrain using points in VW, but that is making a bad surface from good data as it doesn't take into break lines, so the the way the triangles are created cant be controlled.

 

The surface in general wont be correct unless it has no real features like tops, toes, kerbs, retaining walls, batters roads, drains etc. The DTM cant be controlled either like the above example.

 

I have uploaded two screenshots. One has the surface created correctly using breaklines (note the retaining walls and drains etc. The other one is the same data but the surface has been created without breaklines. I have also uploaded an example dxf with just a surface (3d faces) already created if you want to play around with it.

 

I want to be able to send my clients a dwg, dxf or LandXML with a DTM terrain surface in it and have them import it into VW as a site model with a couple of clicks and start designing, not have to have them trace contours or have to send them an ascii points foil so they have to create their own bad surface .

Screenshot 2024-07-10 134005.png

Screenshot 2024-07-10 155521 Points.png

Example Surface.dxf

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On 7/10/2024 at 8:08 AM, SimonF said:

Wouldn't it be nice if VW just imported a DTM surface that was already created and in a CAD file like every other CAD package? Rather than badly recreating a site model from points.

 

I would be happy to learn about another CAD program that imports a surface from another program with its original, program specific modifiers! I have been working between AutoCAD/Civil/Vectorworks/Archicad/Rhino/Sketchup, and barring some decent interplay between Civil and ACAD, none of these can do much of anything with an imported mesh, without a lot of work. Though I haven't worked much with Revit yet, it notoriously does not play well with others.

 

I should point out that Revit, Archicad, and Rhino also do not support geolocated drawings and coordinate transformation, or GIS service connection, which I am sure you can appreciate as a surveyor is very valuable feature in Vectorworks when we work with surveys/import/export.

 

While Vectorworks is adding full LandXML support in the upcoming version (i believe), as Jeff points out, most site models we make, or recieve from surveyors, are used either as early input or as verification for our own site models for specific features/areas.

 

It seems like the only thing you are missing is the direct import of breaklines, but if you are exporting a survey file, you can also export the points as well as the breaklines in the form of 3d polylines. Both breaklines and polylines are, after all, a series of connected points.

Edited by Poot
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Thank you for your reply Jeff and Poot. You are correct, I am not a native to VW

 

I have a couple of ArchiCAD clients and VW clients. I have been investigating this based on what my clients have asked for and told me.

 

I get paid to do a good survey that i take pride in and then send it off, and how the client uses it is up to them. However I was so confused when they told me that they were tracing contours to create site models or asking for xyz points files to create site models. I want my clients to love the service and data that i provide and knowing that they were badly recreating something that was already created was haunting me. I have spent far too long at various times searching the help and forums for importing dxf for site models with all i could come up with being the points import posts like this one.

 

Im much happier knowing that it can be done and once my my clients work out the required steps (or if you can post them below for everyones benefit that would be amazing) I wont have to create xyz point files and know everyone is using a good DTM

 

I had stripped everything else out of the previous file for the example except the 3d triangles, but normally my DTM layer has all the points and breaklines to create a surface.

 

I have included a file this time with no 3D triangles, but just the 3D points, breaklines and extent that i use to create the surface, so as per Jeff's comments above, I assume this is what you would use as best practice to recreate the DTM in VW? If so, would you mind sharing which commands and steps do you use to get this file in and setup as your site model?

 

Ideally I like to supply:

- a CAD file with the DTM points and breaklines and the other features such as existing buildings, services, windows, trees, property boundaries etc

 

I also fly the drone when required and ideally like to produce and supply

- A high resolution georeferenced ortho image .tiff created from drone imagery great planning, site understanding and for digitizing ancillary information that wasn't necessarily requested or thought of. 

- Point cloud file (supplied in any common point cloud format) from the drone which is great for rendering existing neighboring buildings next to new designs, basic modelling of neighboring buildings or identifying features such as solar panels or complications when designing extensions to existing buildings.

 

 

Example DTM points and breaklines.dxf

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9 hours ago, Poot said:

I should point out that Revit, Archicad, and Rhino also do not support geolocated drawings and coordinate transformation, or GIS service connection, which I am sure you can appreciate as a surveyor is very valuable feature in Vectorworks when we work with surveys/import/export.

 

I agree, I have spent time with Rhino I love the design features, but as a spatial data person, having to block shift spatial data to then use it and then block shift it back to output it so that it can be used alongside other spatial data was time consuming and frustrating

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10 hours ago, SimonF said:

have included a file this time with no 3D triangles, but just the 3D points, breaklines and extent that i use to create the surface, so as per Jeff's comments above, I assume this is what you would use as best practice to recreate the DTM in VW? If so, would you mind sharing which commands and steps do you use to get this file in and setup as your site model?

 

 

there are tutorials on Vectorworks University can teach you how to do that and do much more.  There are also lots of threads on this forum covering the use of drone photography for site model texturing.

 

you’re going to find that the vast majority of people don’t actually know what they are doing with site models.  They will insist on using contour instead of points (too much data), oftentimes do not know how to use break lines as site modifiers, and struggle with georeferencing and origin issues.  This is not unique to Vectorworks.  The reason this problem exists is few learn about these things in school or during apprenticeship.  Most of these topics are fairly new for seasoned professionals who have recently moved to 3D and were previously satisfied with inserting a PDF of a survey into their drawings for context.  Surveyors and Civil Engineers usually get it because their work depends on it…. Archies and Land Archies not so much.

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On 7/10/2024 at 5:10 PM, Jeff Prince said:

 

 

Welcome to the forum.  I don't what your experience with the software is, but I'm guessing it's extremely limited based on what you have posted.  As a surveyor using different softwares, you should know that each package can display data in different ways and it is always just an interpretation of real world data that can be skewed to suit a variety of purposes.  Vectorworks does a pretty nice job of taking in a DTM such as the one you provided and replicating it exactly, you just have to set the site model setting correctly.  By default, Mesh Smoothing is turned on because that's what most people want to see, a nice smooth surface.  If you want it to look like a TIN, just turn the mesh smoothing off.

ScreenShot2024-07-10at07_34_27.thumb.png.11b5ce0c47736f7cdfbabe416a124ea3.png

 

So here's an example from Vectorworks using the DXF you provided.  One of these objects is your DXF simply imported as 3D polygons.  The other is a site model generated from that data.  Can you tell which is which?  No, you can't visually, because it is the same data and I choose to display it accordingly.  The only refinement I did to it was to add a crop boundary to the site model so VWX wouldn't connect the edge conditions of the model, turn off 3D contours, and change the fill color from green to white.  I also modified the Render Mode setting by decreasing the Crease Angle so it would be easier to see the facets in the VWX site model.  This took all of 1 minute from start to finish as it is common skills and practice when dealing with site models.

 

ScreenShot2024-07-10at07_37_22.thumb.png.75c17fa0eed4eafaf8597deb1a77f89a.png

 

But here's is the really important thing you need to get.  If you give your client a survey for use in vectorworks, you better include the DTM (existing conditions model) AND the points, breaklines, retaining walls, stairs, etc.  that help define that DTM.  Why?  1st it allows me to recreate the DTM from the primary source data which should result in a very similar DTM to the survey version.  Then, when a Landscape Architect like me wants to reshape the site, I will be using site modifiers to control the DTM and will probably end up needing to modify your breaklines, etc. to create the proposed condition.  If I'm limited to working in your mesh of triangles, my work becomes tedious compared to points and lines.

 

Attached is the model I made from your DXF if you wan to see how thing behave.

 

yes you can.vwx 747.73 kB · 1 download

Hello Jeff Prince, thanks for your reply.

you can still spot some differance and problems in recreating the triangle, sometimes it missrepresent it, and sometime it create more than is already there.

 

i totally understand what SimonF is talking about, since i personally had the same problem when importing a 3D mesh, and convert it into DTM, somehow Vectorworks doesn't use the same Triangles from the mesh, and create its new one, resulting in problem in represnting what is already been created, either from a surveryer data, or from another 3D modelling program.

 

i can't figure out why vectorworks is doing that.
 

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32 minutes ago, Moe_90 said:

Hello Jeff Prince, thanks for your reply.

you can still spot some differance and problems in recreating the triangle, sometimes it missrepresent it, and sometime it create more than is already there.

 

i totally understand what SimonF is talking about, since i personally had the same problem when importing a 3D mesh, and convert it into DTM, somehow Vectorworks doesn't use the same Triangles from the mesh, and create its new one, resulting in problem in represnting what is already been created, either from a surveryer data, or from another 3D modelling program.

 

i can't figure out why vectorworks is doing that.
 


You need to visit the example i posted and all should be clear.  If you upload a properly triangulated DTM, vectorworks is going to use each verticie in that model to reconstruct the surface, it’s not going to invent new data, except at the edge of a non rectangular site, which is why you need a crop.  If you use a different display mode like “smoothed mesh”, then sure, it’s going to look different, but that’s how all the other DTM software behaves too.  The underlying data is the same.

 

Do you have an example file where you can demonstrate otherwise?  Post it and I’ll take a look.

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On 7/12/2024 at 5:04 AM, SimonF said:

I agree, I have spent time with Rhino I love the design features, but as a spatial data person, having to block shift spatial data to then use it and then block shift it back to output it so that it can be used alongside other spatial data was time consuming and frustrating


Since I have often meant to ask - what program do you primarily use to make and output your survey data (into DWG for example)? Is this something like Civil3D?

 

I am just curious as I often get survey files where the coordinate point + height data do not import into Vectorworks correctly - arriving as either 2d text and 3d lines of the X mark (instead of loci). The same files look like they have 3d blocks in the autocad viewer, and I dont currently have a copy of Civil I can use to check.

 

It may be a problem on the VW side, but it would be nice to find a way for us to avoid this issue.

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13 hours ago, Poot said:


Since I have often meant to ask - what program do you primarily use to make and output your survey data (into DWG for example)? Is this something like Civil3D?

 

 

Hi Poot

 

I use a combination of Trimble Terramodel and Trimble Business Centre for producing my surveying work. I generally export as a DWG unless asked otherwise. There will only be 3D points and sets for breaklines and DTM edge (no 3D blocks, text, crosses etc) for surfaces.

 

I think you can still download a copy of Trimble Business Centre and use it without a license to view data in 2D and 3D (just cant process, draw export etc) which would be a good option if you want to look at supplied files.

 

Also 3DR Viewer is a good 3D viewer for point cloud and 3D data

Edited by SimonF
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