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zoomer

Site Model - Z height shift (Sea Level vs Building Level)

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1.

My building is located at Z-Height first Floor = 0.00

All Building data I get is for that Height Level.

 

The Site Model Data is over Sea Level and away from VW Origin.

Also all further data and changes for site will come at Sea Level.

 

 

Of course I moved my Site Models to the Building as always.

But this time for this project, when Editing Site Model Data, Existing or Proposed

I want to keep the Sea Heights inside of my Site Model.

 

One Site Modell already is completely off but the Second works this way.

(Aligned to Building but Sea Levels inside)

Looks like I aligned its Z-Height by setting a "Start Contour Offset"

Other people mentioned one should move it by adjusting the Site Models Layer height.

 

Which is correct ?

Adjusting "Start Contour Offset" or "Layer Height" ?

 

Or is there even another better way ?

 

 

2.

For the XY offset for source files,

beside modified user offset when importing,

does it make sense to "georeference" a Layer with Site model Data to position along your Building,

although you have no clue which, or if there is at all a projection ?

(but because there is also such a nice Angle setting option)

 

Or would that distort/destroy the Geometry ?

Edited by zoomer
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I'm not an architect @zoomerhowever I usually build the model and drop in any structures. Exact elevations are not as critical for me as others but when a floor height is given, once the building is placed I usually select a front or rear view, select the building and set the floor to align with given height using place by points. Probably a bit rough for your application. Not sure of your second question as I haven't had to geo reference anything yet.

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Yes, that is what I normally do.

 

Now it is just laziness that I don't want to recalculate between Sea and Model Level

when I get a few new Stake Positions.

 

With VW 2018 testing I tried Start Contour Offset which may not have worked and

Layer offset. When moving the contours up I forgot to also move one proposed

Pad Modifier which stretched my Site Model. That brought greater havoc to it.

Now half of my Texture Beds are destroyed too.

In fact the whole Site Model is corrupt now.

All in all, Layer Offset may have a lot of drawbacks.

 

And I do not know what is user error and what might be VW 2018 bugs.

I redo everything in VW 2017 now.

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Easiest thing to do is raise your building to use real-world levels, but you say in your original post that all the data you get for the building relates to 0.00?

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Yes, and I would say that the 0.00 from 1st levels finish floor is my main height level.

Important from an architectural view.

 

I would like to work with my Site Model in the same way as it is easier to understand

where terrain heights are. But the LA works at sea level (and 2D only ?) so I get his

stake markers in sea level some 5xx meters off.

So not very illustrative, from my point of view.

 

And to re-create and update his stakes, I would like to keep an option to temporarily

work somehow in his sea level.

Edited by zoomer

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1 hour ago, zoomer said:

Yes, and I would say that the 0.00 from 1st levels finish floor is my main height level.

Important from an architectural view.

 

We could with the ability to display two Elevation levels, levels relative to sea level and levels relative to a local datum (e.g. ground floor level as 0.00). So you could raise Storey levels to work to sea level but also display levels relative to ground floor 0.00.

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On 9/19/2017 at 11:44 AM, zoomer said:

I would like to work with my Site Model in the same way as it is easier to understand

where terrain heights are. But the LA works at sea level (and 2D only ?) so I get his

stake markers in sea level some 5xx meters off.

So not very illustrative, from my point of view.

 

And to re-create and update his stakes, I would like to keep an option to temporarily

work somehow in his sea level.

 

The 5xx meters off, is that for the x coordinates and is 5xx actual meters in the 500 meter range or even 500+ km? If the latter then the stake markers are probably in a UTM coordinate system as they have a false easting (x) of 500 km, though it could be another coordinate reference system as well.

Regarding sea level, and not trying to open a can of worms :ph34r:, is that mean sea level (MSL) (most likely as that is common), another sea level or chart datum?

What kind of file is the LA supplying you for the stake markers? And what makes you think it is in 2D?  I've seen such drawings in 2D with elevations next to the marker, but there can be various reasons why it ends up as two 2D in VW.

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No, XY are far ofF, it is the Heights that at 5xx, xx meters from my 0.00 finish floor.

 

Sea Level normally is North Sea in Germany while Switzerland uses Adria Sea Level.

But it looks like the surveyors DTM and the DTM from the City use slightly different Levels :)

 

No stakes.

2D Text only points data from surveyor but a 3D Mesh model and a larger 3D DTM from the City.

The LA ships PDFs and DWG in 2D.

LA working 2D only is just an overall conclusion :)

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O.oO.o

It looks like the surveyor and the city didn't communicate too well with each other 9_9

 

Now the big question is whether the heights are correct. But in any case they should have specified the coordinate system, so you could use that as the basis for your georeferencing to put your building at the right spot. The surveyor should be able to provide you an x,y,z file for the coordinates. I'd use the city's DTM file in this case. In your case I'd use layer height for your building and keep your DTM layer at Z=0 so that your DTM will not get compromised if you have to do any calculations, modifications etc., unless you have a "bottom floor" defined by setting the datum elevation. If only for visual purposes the start contour offset might work as well if you find that easier to do, but that is for the 2D contours.

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Thanks Art V but georeferencing isn't important from planners and my side.

The surveyor set a fix point. This our start of the building grid, slightly tilted from north.

The given terrains are already positioned and rotated.

 

DTM is just entourage for Visualization and personal ambition.

But it should contain what the LA's work.

 

My important main level is Arch 0.00.

When I do some pads and retaining edges for the buildings I would prefer to do this from 0.00 Level,

but that's not so important.

It is just that I will get height definitions from LA from time to time - at sea level.

I would like to reference his 2D plan and create some proposed stakes or draw over some texture beds and

pads without the need to re-calculate.

 

Currently DTM is still moved up to 0.00

I will have all my Modifiers on the DTM Layer. I think it is a good idea if these share the same DTM height level.

So far I think offsetting the DTM Layer may be the best idea ?

 

Beside that drawing 2D geometry for Modifiers will then happen 500 meters below my DTM.

 

 

 

 

 

Edited by zoomer

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Thanks for clarifying, my workflow is definitely a bit different from yours in this case, but then I don't do architectural things. In my case 99+% of DTM use also involves contour lines and data that have to be exchanged back and forth with GIS users so it's almost always georeferenced etc.  There have been maybe two cases where I had a "standalone" DTM like yours over the past decade. Given the increased use of GIS I assumed you would be working within a real world coordinate system as well with a DTM instead of a local project coordinate system.

In your case then I would probably do the same as you described.

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Yes, I asked about (misusing) georeferencing because it has a nice angle setting :)

But found that under projections settings there is no "none" to choose.

 

I think I can't georeference my whole file because I get all Arch data on 0.000 anyway.

but maybe that would help for a single Layer only to import contours.

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On 9/20/2017 at 9:27 PM, zoomer said:

Yes, I asked about (misusing) georeferencing because it has a nice angle setting :)

But found that under projections settings there is no "none" to choose.

 

I think I can't georeference my whole file because I get all Arch data on 0.000 anyway.

but maybe that would help for a single Layer only to import contours.

Can of worms alert :ph34r:

There is a way to "georeference" your site but it would require you to define your own coordinate reference system (CRS). If you happen to know a friendly geodesist you could try to ask him to do that for you, create a shapefile with the projection etc. info, import that into VW and then you will have your "georeference". You could have it somewhat linked to the actual CRS being used by having your friendly geodesist create conversion parameters to bring it back to the original CRS. Now how to make the latter work within VW is something you will have to ask Jim. Of course there will be other things to consider, but your friendely geodesist should be able to explain that.

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Ufff :$

 

I think offsetting user origin + rotating may be a way that I can remember a bit longer  :)

 

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4 minutes ago, zoomer said:

Ufff :$

 

I think offsetting user origin + rotating may be a way that I can remember a bit longer  :)

 

Yes, probably a lot easier :)
Just remember to unrotate when reading out coordinates if you have to.

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Oh no,

Layer shifting does not work here.

VW 2017 but I had the same havoc in VW 2018.

 

Site Model was at 0,00 like Architectura Data.

 

1. I lowered the Site Models Layer by -Sea Level

2. Contrary I moved my Source 3D polygons up by +Sea Level

 

Everything looked good.

Site Model is at correct 3D height from Building Level,

Top Plan Contours and its Height Labels are fine.

 

But as soon as I enter the Edit Source Data Mode

(btw Site Model Plane as the only choice)

my 3D Polys show a wrong Z-Height ! (Maybe double height ?)

 

This way I can't really edit them nor add any stakes with my given height information.

 

 

 

Additional to this height issue,

I want to mention that when in any VW orthogonal Side View

(which VW calls a "3D" View),

snap to an Objects Point to read out its Height,

the Coordinate Fields at the right bottom of the View Pane show arbitrary offsets in Z :

for the right column = relative height from current active Layer height.

(Overall VW height in left column is ok)

 

There is always an arbitrary Offset in Side Views.

While it works correct in a "real 3D" View like Isometric.

Edited by zoomer

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I found a workaround.

 

You shall not lower the Layer :)

You have to keep the Layer on 0,00 m but move Source Contours up and afterwards

your Site Model's Z value down again.

So Site Model Surface has correct height and 3D Poly Editing has correct Height.

 

But generated Contours Height Labels are off now in 2D.

I can have an additional Start Contour Offset = + Sea Level or not, but I can't see that

it does what you expect or even anything.

 

Edited by zoomer

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Err.... I guess I'll have to try sometime, but for now I'll stick with aligning my stuff with the site model instead of the other way around. :)

But I'll save this topic for reference.

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