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Site survey data - do I have the correct data?


Nathan_UK

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Hello all,

 

I am unable to correctly use survey data to create a usable 3D terrain. I have attached a screenshot and file of this exact data and I would appreciate your help.

 

I have watched many VW videos showing how to correctly import and clean the data, this is what I am stuck on...

 

1: The lines shown in the uploaded image are simply that, lines. They are not polylines or polygons.

2: The crosses shown are not loci and the OIP shows they hold no z-value data

3: All of the learning material I have seen show a polyline/polygon as holding one z-value (i.e. 110 metres). Looking at the data I have, one of these lines can vary from 112m to 121m so I don't believe the lines could be successfully converted to a polygon to convert to 3D data.

 

So, how do I turn this data into a 3D terrain?

 

I do have further questions regarding modifying the terrain but I should get the basics done first! I appreciate your help

 

Screenshot 2019-01-21 at 16.12.38.png

 

Edited by Nathan_UK
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Guest Wes Gardner

Hi Nathan,

 

If you have 2D polys that represent contours go here and do this:

AEC > Survey Input > 2D Polys to 3D Source Data

 

You'll then get a dialog that asks you for a starting elevation and then asks you to establish a height for each of the soon-to-be contours.

Once done go here:

 

AEC > Terrain > Site Model from Source Data

 

You should be able to build your site model from that...

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Guest Wes Gardner

@ line-weight

true dat....

 

So the options are to either compose all the individual line segments into a polygon ( Modify > Compose  -hold down the shift key and select lines that are touching end-to-end to create your contour) OR trace over them with the polygon tool...

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3 minutes ago, Nathan_UK said:

Thank you @Wes Gardner & @line-weight for your comments, however, I cannot see how I can attribute a z-height to the lines after conversion to a polyline. Only a handful of the lines have a height value directly on them, whereas all of the crosses have values written next to them, are these crosses what I should be converting? 

 

 

 

You just have to infer it from the spot heights. It looks to me like the red lines are at 1m intervals, and the blue ones at 0.25m intervals.

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I imagine the survey company will have infered the contours from the spot heights. The spot heights will be the actual data they measured. I think you could also generate your site model by making the spot heights into loci and giving them exact z-values. In theory that ought to give you the same model and if you extracted contours from it they would be in the same place. Can't remember exactly how you would go about that but I think it would be possible.

 

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Using the 3D modelling toolset (I am using the architects VW license) I can choose '3D locus' and simply put one on-top of the existing spot heights. Your z-value can be input directly into the OIP. As an experiment I shall take both courses of action in two different models and share them here so they can be compared ongoing incase someone else comes across this decision in the future.

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Guest Wes Gardner

Additionally, you can use the Stake Object tool inputing the number next to the "X" and create a site model from them...and you're probably correct in that "close enough" will work...it's certainly good for horse shoes and hand grenades as they say  🙂

 

 

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Hello all,

 

I have found manually putting in 3D loci at each of the spot heights I could not create a site model, this is definitely an error on my part. I have had better success with the polylines. I encountered the same issue as I previously have which was the z height written was not actually the z height of the model. To overcome this I manually moved (command-M) to the correct height to make it workable. @Wes Gardner I could not find the stake object tool in my 'architect' license, other resources on Google appeared to be historic, can you advise me where I could find it please?

 

Many thanks

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Guest Wes Gardner

@Nathan_UK - the few site models I've created,  I used the polygon approach and then modified it with site modifiers.  I know there are folks here and in the Landscape group who have many more tips than I...

 

Wes

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