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Creating a surface from 3d polys


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Hi Ok a nubie here so be gentle! Here is what I want to do....

Create a model in 500mm blocks of a hillside in aberdeen... (long story).

I can get terrain via google maps/ sketchup. The problem is the resulting terrain is pretty useless in VW its a series of 3d polys. I want a shape I can project onto and or shell. The best I can do so far is drape it but the resulting nurbs surface wont shell and you cannot project onto it a solid either. I have no idea why.

I should add that the result I want is a scale model of the hillside not at 1:1 so the file I uploaded could be one 500mm block

Many thanks Will

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Here's a wild idea. It may or may not actually work, but it's worth a try... First create a Site Model (which I think you have already done). Then create a 3d (or hybrid) Symbol of the 500mm Block. Next, on a discreet class (just for sorting purposes later) and in Top/Plan View, use Duplicate Array to populate the entire hillside with the Block Symbols. Then Select all the Block Symbols (easily done using Custom Select command) and then run the Send to Surface command.

If it works (and I'd love to know whether it does!) you should end up with all of the blocks sitting ON the surface of the Site Model. At that point you might want to select them all, then go a front (or side) view and move them all down a certain amount so that their tops are more closely coincident with the terrain...

NOTE: I suggest experimenting with a small number of blocks first, as proof of method... Have fun!

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Hi Peter thanks that's a good plan excep I cannot send even one block to the surface as for some reason the send send surface command won't work on the 3d poly or the draped surface I took off it! The thing is I don't want to have to draw the surface of each hill I want to grab them of google earth via sketch up. The problem is changing the sketch up surface to one that will accept the send to surface command. Or can be shelled?

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Ohh I should say this is me working it out. I imagine the hills will be over one or two 500 mm blocks (to be carved in china). The whole hillside will need to be collected from google earth via sketch up chunk at a time as its restricting the amount of terrain I can grab at a time. Then I reckon I can fit it together. Next I need to make it into something I can work on in VW cut it into blocks with gaps between and rescale to a decent size? Maybe I can trick VW by adding a dim layer in another scale to fool VW not sure if that will work but could do?!

Cheers Will

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The point was to make a SITE MODEL in Vectorworks. The Send to Surface command is designed to work with Site Models, and only Site Models... You can use the TOPOG LINES from a map (or a survey) to create the Site Model. The rest should works as outlined above...

Oh ok ill try that if I can rip the lines out of the draped surface then use the loft surface or whatever it's called to create the surface ?



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Well what works sort of is redrawing the contours on the 3d polys with the 3d curve curve tool this seems to snap to them even in top plan so boring but doable. Then create a loft surface then duplicate an array convert to nurbs and project to surface. Thank for the heads up about the loft surface being the only thing you can project to Peter I will get cracking now!


Edited by Utectok
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Well what works sort of is redrawing the contours on the 3d polys with the 3d curve curve tool this seems to snap to them even in top plan so boring but doable.

If the SketchUp surface can be imported into VW, maybe the contours for a Vectorworks Site Model surface (also referred to as a DTM or Digital Terrain Model) can be generated by the Contour Tool. It's way down near the bottom of the 3d Tool Set. This would save the effort of tracing contours.

The Contour Tool produces NURBS curves. Convert these to 3d Polys, run the Simplify Polys if needed, Create the new Site Model via AEC>Terrain>Create Site Model.


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Ok so I should be able to convert the imported 3d poly straight to a site model saving all the boring bit? BTW the loft surface accepts the project onto command so maybe it works with them and site models ?

Listen also a big thanks to the posters it's really helpful stuff guys I'm usually ok with 3d stuff but Nurbs are new to me!

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Ok I tried to create a site model and I just get the spinning beach ball of mac doom.

Application not responding.I tested the 3d polys and it seems the I have overlapping 3d polys although I am unable to see which ones or why? I tried importing again from sketchup in case I moved any accidentally but its the same.So basically I cannot create a site model from the 3d poly file it seems?

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Another way which we have started using is to get SHAPE files from the local authority. These are often in the public domain or can be obtained free of charge.

Make sure you get the 3d polygons which you can then use to create a site model. When you have done this create a drape surface and texture with the Google image.

The shape files will cover a larger area than you want but simply cut and paste what you need. Shape files are also geo referenced so can fit to a geo-referenced layer.

Shape files contain a huge amount of data for councils and will - for instance have polygons for all building footprints. Using the modify by record field we recently produced a 3d model of the city centre of Wellington in about 2 minutes!!!

Edited by BillV
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Maybe this from OS would help?


Data type: Vector (Contours), Grid (DTM)

Supply format: DXF [Contours],

ASCII grid [DTM],


Version: 04/2010


This product is supplied both as a set of contours and spot heights (Contours) and as a gridded digital terrain model (DTM).

Panorama data was collected between 1970 and 1980. This product has not been updated since this date

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