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cberg

Terrain Model Datum?

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Is there a way to set a datum elevation of a terrain model? 


For the past year or two, I've been making terrain models by using 3d loci that have actual 3d elevations (above sea level).  This means that that site models are hundreds of feet above the Z=0 Plane. 

 

Architecturally one typically sets first-floor elevation at 0'-0".  And typically architectural model layers are set up much closer to the ground (so to speak).

 

To bring a building and a terrain model together, I typically establish an arbitrary datum elevation and move a copy of all the site model elements (including modifiers) down to meet the building.  However, once doing so, none of the topo labels are accurate and making any changes to the site or its modifiers is tricky (requiring math). 

 

How do others handle this?  Is there a way to recalibrate the terrain model labels so that actual topo labels read correctly?  Or are there other techniques for bringing these two design elements together?  I have found referencing a terrain model present problems with section viewports, so I don't do that.  Maybe there are functions in the program that I don't fully understand. 

 

How do others bring site and building together?

 

 

 

 

 

 

Edited by cberg
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How about using a Design Layer Viewport of the Site Model and placing it on a design layer with an elevation that matches the elevations of the building? Then, just keep your original site model design layer hidden in your viewports.

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Let me experiment a bit with this idea that to see how everything works. 

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Maybe I don’t understand fully but why not just set the design layer elevation(s) for your floor(s) at the height above sea level. Your Bldg model will then sit correctly with your dtm and the dtm contour tags will be correct. This is how I set up my models. 

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Let me think about that as well.  In the past, we've had issues with models set at the height above sea level.  Maybe this was with older models that were started before 2018.  But the unified view options acted super funny.  Zooming to the model extents became problematic.  Or maybe there was user error.


 

Edited by cberg

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Most of my work is relatively close to sea level so maybe I don't get those issues because of that. I understand modeling too far from the user origin, (including in the z direction) can cause some issues, though I haven't experienced any probs because of that to date.

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Another way to do this is to create the building in a separate file, and reference it into the site model file, (using a Design Layer Viewport), or, reference the site model into the building file, again using a Design Layer Viewport.

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@Tamsin Slatter Sorry to revive this thread but I'm going through this now and am curious to explore the two recommendations that you've made. Is there a tutorial that would show me how to apply these two suggestions? I'm not sure how to go about to use viewports as you've described in your two recommendations. Can you elaborate or guide me through the process?

 

Thanks kindly!

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I may be missing something here but just set the layer elevation of the design layer to match.

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On 8/29/2018 at 8:28 PM, Tamsin Slatter said:

Another way to do this is to create the building in a separate file, and reference it into the site model file, (using a Design Layer Viewport), or, reference the site model into the building file, again using a Design Layer Viewport.

 go create viewport, for where to place the vp choose a design layer. You will then get the option to choose a referenced file. You won’t get this option if you choose to place the vp on a sheet layer. Browse to and choose the file you want. then you can choose which design layers you want to view from the referenced file.

 

Tweak other settings to suit and go ok. 

 

You up will get a refencenced VP. You can now crop rotate or move this viewport however you want. You can change class and layer setting also just like any other vp

 

You will need to update the reference if You make changes in the referenced file. The reference tab in the navigation palette shows out of date references in red.

 

that’s a quick summary!

good luck!

Edited by Boh
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No! it should not! To double check I created a basic terrain at 200' Elev then set the layer elevation to -200' and all is fine!

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You could also set the building elevation layer up to match the DTM

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1 hour ago, bgoff said:

No! it should not! To double check I created a basic terrain at 200' Elev then set the layer elevation to -200' and all is fine!

@bgoff I'll give it a try. Thanks for the info.

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1 hour ago, bgoff said:

You could also set the building elevation layer up to match the DTM

@bgoff That potentially creates a lot of headaches keeping track of storey and layer elevations, etc. If possible, I'd like to keep my first floor at 0'.

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2 hours ago, MaltbyDesign said:

@bgoff That potentially creates a lot of headaches keeping track of storey and layer elevations, etc. If possible, I'd like to keep my first floor at 0'.

i use the same techniques as bgoff. set your building stories with your datum at Z=0, then set your site model layer to the negative eleveion required. When you are placing a site modifier in the site model layer, use the correct elevation, ie. ignore the fact that you have set a negative layer elevation. 

 

however, if you want to use the correct elevations, for example with the elevation benchmark tool, then it is best to set all the layers and stories to the correct elevations. I know you can get around this, but using the correct elevations for everything means less work with the elevation benchmark.  

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Jonathan, so true. The fact that there are a few workarounds can make it a bit confusing. I try to tell people to play with a few and find what works for their workflow.

 

However to all those reading this Jonathan is a master at all Vectorworks so he may have a number of tricks Im not even aware of.

 

Thanks for jumping in here Jonathan. Always glad to get your tips and tricks!

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Posted (edited)

Have yinz (you all) explored keeping the DTM at it's true Z elevation and referencing it back in using a site model snapshot?  I've been thinking of setting up a model like this and was wondering whether this has any advantages or benefits...

Edited by cberg
language localization

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10 hours ago, cberg said:

Have yinz (you all) explored keeping the DTM at it's true Z elevation and referencing it back in using a site model snapshot?  I've been thinking of setting up a model like this and was wondering whether this has any advantages or benefits...

I havent tried that.

The reason I wouldn't use this is that all the site modifiers would have to be in the site model layer, or at the correct Z level in other layers. My method keeps the site model information at the correct elevation in the site model layer and at the recorrect relative elevation in any other layer. 

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