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Jonny31

Extrude from DTM

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Hi All,

On my digital terrain model, I have draped areas from my 2D plan and want to extrude these surfaces so they follow the landform. So far I have only been able to send the 2D polygon to the surface and then extrude it from there. Is there anyway of showing a 3D shape that has a constant height that matches the contours? Any help would be much appreciated.

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You can create a shape over the site model and convert to a nurbs and then use the 3D tool "Project' to project down to the model.

HTH

 

Site Model.vwx

Capture.JPG

Edited by Alan Woodwell
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Hi,

Sorry for the slow response. Thank you for that advise Alan, very useful but not quite what I was after. These aren't specific objects but rather just 3D shapes that represent a block of houses.

Cheers

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Not sure why the extrude is needed?  Thickness = max height of the houses?

•A texture bed would work if you just want a shape with color fill that follows the terrain.  In the Texture Bed OIP, turn off the 3d component.  You can still put pads and houses and other stuff on this part of the terrain.

 

•If some thickness is required, several steps are required:

  1. Select the Site Model
  2. Model>3d Power Pack>Drape Surface.  Accept the defaults in the dialog.
  3. Add color fill to the Drape.   Adjust U/V point count in OIP if more detail needed.
  4. In Top Plan View, Create outline of the housing block with 2d tools.
  5. Extrude the poly so it passes through the Drape.
  6. Select the poly and the Drape
  7. Model>Intersect Solids. Result is a patch of surface following the terrain.
  8. Engage the Shell Solid tool (3d tool set). Hover/Click the patch to highlight it. Press the green checkmark (or press Return/Enter)
  9. Adjust the height of the Shell in OIP.

Or did you mean something else?

-B

 

 

 

 

Terrains.png

Edited by Benson Shaw
Clarity
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Have you considered using your 2d polygons to create Massing Models and then Landmark>Send to Surface?

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Benson, thanks for your advice. The second option you have provided is exactly what I want to do. Have tried the steps you suggested and I can get up to step 8 however when I try and shell solid the solid intersection, it just locks the solid intersection. When I unlock the solid intersection, the shell solid tool still doesn't seem to work - because it isn't changing the name of the solid to a Shell Solid I guess. I can get to tool to work on an extruded rectangle. Any suggestions as to why?

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Should work with the Solid Intersection, but here is something to try:

Select the intersection (it should a shape that mimics the surface of the site model). , Then Modify Menu>Convert>Convert to Generic Solid.  Try to shell that.  Mine shows locked Generic Solid for a moment, then completes the shell operation.

 

-B

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Also, just to be complete about working with the Shell tool:

•Engage the Shell tool (3d tool set).

•No need to have any selected object(s), but it's ok to have object(s) selected.

•Hover over the object to shell (eg the Solid Intersection). It highlights as a red surface.

•Click to select the highlighted area. It stays red when cursor moves away.

•Move cursor to green checkmark in upper left corner of VWX window.

•Click the green checkmark. The Shell dialog appears.

•Accept defaults and wait. Usually, after a few seconds, the Shell is displayed.

•Adjust the resulting shell parameters in OIP as needed.

•If the Shell fails, try again, but in the dialog, reverse the direction, and/or reduce the thickness.

•Note: zero thickness is usually accepted. But sometimes not.

 

OK, good luck!

 

-B

ShellTool.png

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OK, just tried three new Solid Intersection shapes on the same DTM.  Lower one shelled OK. Upper two failed to shell.  Not sure if scale is an issue.  This DTM is 50' x 100' with 20' rise.  Shells are 4" thick.

 

So, tried one as Menu>Convert>Convert to Generic Solid.  Still fail on Shell.   But then convert the Generic Solid to NURBS was successful.  I used the MacOS key command for Convert to NURBS (opt Cmd N). Or Modify Menu>Convert>Convert to NURBS should produce a NURBS Surface.  Then, that shelled as expected.

 

Another I converted from Solid Intersection directly to NURBS.  That also shelled as expected.

 

Not sure why some shapes shell directly from the Solid Intersection, but others need the conversion.  NURBS usually best choice.

 

-B

Shells.png

Edited by Benson Shaw
Just horsing around
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Old post, but similar problem here. I am trying to figure out best workflow for creating a hedge that follows the terrain. 

 

I don't need to display individual plants,  I would be happy to have just a 3D block and add texture.

 

@Alan Woodwell , I followed your steps several times but I get stuck after converting to NURBS. 

 

If I convert to NURBS, Extrude and then send to surface, the 'hedge' doesn't follow the terrain. 

 

If I convert to NURBS and send to surface, the 2D 'hedge' follows the terrain but I am unable to extrude it using the Push/Pull tool, which is what I assume you refer to when you mention the 'Project' tool

 

Must admit I am new to site modelling, Perhaps I am missing some important passages. Any suggestions? 

Screenshot 2019-08-20 at 14.23.01.png

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Posted (edited)

Could you „Thicken“ the Nurbs after sent to surface ?

 

Edit :

It is called Shell Solid,

as said above.

Edited by zoomer

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@zoomer and @cberg Very useful video and tip...but it didn't work 😞

Perhaps something with my model/workflow. Will keep trying and keep you posted. By the way, does anyone seems to remember you can create a fence and replace it with plants? I am making it up?
 

 

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Posted (edited)

Drape surface is kind of finicky. 

 

I might create a copy (in place) of your DTM into a clean file to do the drape, and any of the 3d solids stuff and then paste the results back into your real model. 

 

 

Edited by cberg
clarity

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The solution is to use the Foliage tool. just draw the shape of the hedge over your DTM set the configuration to Area-Hedge and in the preferences set the height. you can also set the leaf image to anything you desire.

 

Super powerful and super easy.

 

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Posted (edited)

@bgoff  Ummm Area-Hedge is not working for me.

A. Top/Plan. Select the Foliage tool, draw a closed shape over the site model. In tool prefs or OIP, assign Area-Hedge, with send to surface, adjust height or not.

Or

B. Draw a closed shape with the polyline tool and apply Create Objects with Shapes>Foliage>Area-Hedge

 

Result either way is a shape on the ground plane identified in OIP as Foliage Area Hedge with no thickness/height or foliage. Not sent to surface.  Changing class or attributes does not affect. Update DTM does not affect

 

Linear Foliage object seem to work, sort of.

Draw a line with the tool, choose Linear.

A long "render" process ensues, with a dialog, until a hedge is created.

However, during the render, the dialog offers a Cancel button which fails to cancel. I have to wait for thousands or tens of thousands or hundreds of thousands of symbols generate.

 

What did I miss?

 

-B

Edited by Benson Shaw

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Benson, I just saw your post. I will reproduce and send video for you to see.

 

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Ahhh.  Thanks @bgoff .  I was properly executing the steps.  Seems my system balked at the large "automatic" count.  The dialog with symbol generation never appears if the count is past some threshold - maybe 100?  I didn't chase it except to find that a smaller area (automatically fewer symbols) or non automatic count (eg 20 or 50) for a large hedge area produces the dialog and ultimately the 3d hedge object.

 

Couple more comments:

1. The Cancel button on the dialog does not work.  Progress is suspended while click/hold the button . . . but  . . .  Process resumes after mouse release.

2. I see many of those darned clipped/flattened contours on your site model.  What's your method for correcting them?

 

Thanks!

 

-B

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Its in the source data. Adding modifiers where needed help. Let me know which ones you are specifically referring to and ill show you how to fix. 

 

Man I love DTM's.  !!!!!!!!!  🙂

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@bgoff 

Thanks for your attention to this thread! I love DTM, too!


In your video showing process for creating Foliage>Area-Hedge, your underlying DTM appears to have areas of clipped/flattened contours. Or, does the site have walks, walls, excavation or other condition forcing those straight line segments and pointy ends amidst the curves?  Attached image indicates a few apparently flattened contours and also some of the jaggy contour lines.

 

I don't know what causes the jaggies. Any preventative?  Fix seems to be OIP>Edit Contours>Add/delete/move as nec.  Can be time consuming and inaccurate. And may reappear when site mods added.

 

The clipping problem is mesh segments connecting sideways to same contour rather than up or down to next contour. Or sometimes even skipping a grade limits or other mod. DTM used to have access to alter the source data, eg add new 3d loci or short contours placed at elevations between the original contours/points.  This forces the mesh points to connect up and down to the new data.  New (since v2017?) versions have no access to the source data, but have at least 3 other approaches:

•  Save a set of source data, eg on dedicated layer, or in another file. Add intermediate points as needed, then delete/recreate the DTM from the altered source - and possibly lose site mods or other work.

•  OIP>Edit exist/proposed contours can help, but often requires move/add/delete many points on each affected contour. Or add new contour, eg at intermediate elevation. 3d loci have no effect and auto delete when exit the edit.

•  Add new site mod contours or stakes over the problem areas. But, Site mods usually need separation from other site modes, so limits on this approach.

 

Any comments, tips or workflows appreciated.

-B

Clipped contours?.png

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I've ended up at this thread whilst trying to solve similar problem for myself.

 

But if it's just a portion of the site model to be extruded up from the underlying surface... doesn't the "spoil pile" modifier do the job?

 

1923782517_ScreenShot2019-10-09at20_08_28.thumb.jpg.5c8a341a6b517aadde95ae4526417f4a.jpg1832960972_ScreenShot2019-10-09at20_08_50.thumb.jpg.bf6dff882a8fc561a664017656ba7391.jpg

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@line-weight Well spotted. Your knocking them out of the park today!  So, yes, the spoil pile provides part of the need.  A spoil pile can be made via polyline drawn over site model, then Create Objects from Shapes>Site Mod> then in OIP choose Config> Spoil Pile. Add negative or positive value in Elevation, Update the Site Model.  The resulting mod raises or lowers that area of the surface, preserving the surface shape. Multiple piles can be added to any site model.

 

Other parts of this Thick Texture Bed are not quite provided by the Spoil Pile.  The pile is integrated into the site model, so attributes - color or texture - are limited.  A texture bed can be applied to the top, or portions of the top of a spoil pile, but, as far as I can tell, the sides remain site model color.  If multiple spoil piles on same site model, there may be a way to calc actual surface area and volume for each pile, if that's important, but I didn't work it out. 

 

OK, whine whine whine.  But at least this is another workaround.

 

-B

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