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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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