How to CHANGE the topography survey level ?

[juha-pekka.rindell]

Hello everyone !

As a rule there is to have a level called "Sea level" at 0, when importing survey data. Well I did not have that active when importing data and now the level of the terrain is too high. When tried again (after REMOVING all old surfaces and dwg) the system still remembers the wrong level (1st Floor with absolute level) as the basis of the terrain no matter what I do. How can get rid of that information and redefine the surface to start from the sea level ?Importing again at the Sea level view did not help. ( I am using worksets. I did not try remodeling in central file yet. Could it matter? )

[aggockel50321]

If your re-importing the data in a site view, check to see what level the site is associated with, via the view properties dialog.

Rather than recreating the surface, you could go to an elevation view, select the surface, & use the move command to move it down a fixed distance. That might be the safest way.

As far as worksets go, once you've made the change it should save back to central with no problems. The only problems you should have with either option above are with objects constrained to the surface, or objects constrained to the surface's associated level, that you expected to move with the surface.

[juha-pekka.rindell]

Thanks Andrew,

Yes ,
I did move the surface to the right level, but the problem is that when editing the surface points, the elevation is given always as the distance from my First Floor Level (+11 500 mm), not from the Sea Level. And that makes the editing phase a bit complicated to do all the math with elevations like -800 mm etc. Re-importing at Sea Level does not change the reference level at all. Of course I could move down the reference level of the surface if it was not the First Floor, where all the seven floors were built on...
Maybe I will try again re-importing in central file...

[aggockel50321]

Re-importing at Sea Level does not change the reference level at all.
What steps did you use when re-imprting the data. Did you delete the imported .dwg or .dgn used for the original topo on the upper level, and then import the .dwg on the lower level & then remake the topo? If you left the original imported .dwg on the upper level, that might be the problem.

[juha-pekka.rindell]

Yep ,

I made it just like you described.

I removed everything (topo survey dwg + the Revit topo surfaces).
Then saved to central.
Then started from the beginning.

I also tried to make it in central file - no effect.

Now I am suspicious that my elevation base chosen does not sync with the topo system. I am using the shared location and I have relocated the project up. Topo seems to show only project based elevations in editing mode. Any idea how to correct the situation? Do I have to move all the levels with the move command up-wards? Seems to me that then I will have to move separately at least all the section boxes in 3d views and all the linked vertical dwg files (neighboring facades) also? And correct some crop regions .... And some openings in walls ..

[aggockel50321]

Sounds like your problem is the shared location you set up between the imported .dwg & your project file.

Try this:

Start a new project and set the site view's associated level (default level 1) to your sea level elevation (0.00 or whatever it is).

While in the site view import the dwg.

Create your topo, using the above imported dwg.

Once created, take a look at the topo in elevation & see if it's where you expect it to be.

From the site view, import your project (.rvt) file into the topo & align it to match your topo.

Go to an elevation view, & see where your project landed in elevation. It should be correct.

[ita]

I may be mistaken but this is an issue with levels that generally that causes some angst. My good friend Parkinson has discussed this issue a number of times with me and I have taken upon myself to make a suggestion resulting from our chats.

In normal workflow process, many projects are started as sketches at Datum 00 - because the survey is not available, or not warranted . . . or whatever the reason! Later in the project (assuming the project proceeds), when the datum is finally set or the survey becomes available - we have a need to adjust the Datum 00 to a new configuration. Then the fun begins.

:idea: Perhaps an added function in "Locations & Coordinates" - called say Default Datum which is set at a default level of 00 and when the project datum is established, the default level is changed to the new RL and the base level Datum 00 revises accordingly.

And. . . if there were other datum adjustments/changes in the course of the design and documentation, the default value could be reset - avoiding all the issues noted in this thread.

Or is there something the Parkinson and I have missed?