Creating topography with real elevations

[patricks]

I have a renovation project with the existing building modelled in Revit, and I have relocated the project to the actual elevation above sea level, finished floor 342.5'. So my elevations show the floor elevation line with 342.5.

Now, when I try to create the existing topography and enter points based on the existing grades, it creates the toposurface 300+ feet above my model, instead of directly below the model. I'm working with a scanned site plan of the original building imported into my site plan, so am I going to have to actually do math for each of my contour lines and enter -17.5' instead of 325' for my 325 contour line? Is there not a way to make the toposurface go by the "shared" elevation, which is what my levels are set to display?

*edit* also along with that, being that my finished floor is between incremental feet (342 and 345), if I place points at -17.5 ft (which would really be 325), Revit is putting contour lines between my points, because it thinks there should be a line at -17 and -18 below the building. This is not the case, I need a line at -17.5, -16.5 etc. below the building because that's really 325, 326, etc. So what should I do?

Also another question, since all I have is a paper/scanned site plan with actual contour lines, what is the best way to create a toposurface that will have contour lines that match the ones on the drawing? Even though I'm creating the toposurface by placing points all along the contour lines, the lines that Revit draws on the surface don't match the ones that are on the drawing. Why is this?

[patricks]

I also tried creating the toposurface by just inputting the grade elevations shown on the site plan, which made the surface 300+ feet above the model, and then moving it down by 342.5 feet to put it under the building, but then that changed the contour lines because the points that were on incremental feet before are now halfway in between incremental feet. What to do??

[ejburrell67787]

I don't think you'll ever get the contour lines to match the survey exactly as they are interpolations between survey points and Revit's interpolation is unlikely to be exactly the same as the surveyor's.

I think the topo is created relative to the active workplane so you need to be using a workplane set at the actual elevation zero. Otherwise you can do it on another workplane and move it down the correct amount in elevation once you have drawn it all.

Similarly (and maybe helpful?), in one project I am working on I created a level at the correct survey level zero (at something like 27m below than ground level!) so that when I place spot elevations in plan I can set them relative to this level rather than the floor level.

There is a way to control where contours are shown but I can't access Revit at the moment to remember where!

[iru69]

Great questions - I've run into some of these issues as well - unfortunately I don't have any answers.

Not being able to enter in the shared elevations and resorting to having to do the math is excruciating laborious - there's got to be something we're missing?

That Revit doesn't create the contour lines along the points is extremely frustrating - this seems to be related to how Revit also does splines in general, which is equally frustrating (the spline should run through all points - when you move a point, the line should adjust accordingly - like in *AutoCAD* - the Factory needs to fix this).

[ejburrell67787]

Actually scrap that point about a topo being relative to a workplane, I was completely wrong!!

However, if you go to Settings > Site settings you can contol where your contours appear - ie at what intervals and passing through what elevation.

[iru69]

I don't think you'll ever get the contour lines to match the survey exactly as they are interpolations between survey points and Revit's interpolation is unlikely to be exactly the same as the surveyor's.
Well, you could get it extremely close by picking as many points along the contour as necessary - if the contour lines followed the points rather than following the current "formula" which appears quite arbitrary to me. This is a case of poor implementation of contour line generation by the developers.

[ejburrell67787]

Not sure how you have 'relocated the project' to the correct level above sea level, however, I just had a go changing Level 1 to be 1000 instead of 0 and then creating a topo by placing points at an absolute elevation of 1000 and the topo showed up as being at level 1.

Have you got more than one topo and are placing points relative to one that is already there?

[patricks]

Not sure how you have 'relocated the project' to the correct level above sea level, however, I just had a go changing Level 1 to be 1000 instead of 0 and then creating a topo by placing points at an absolute elevation of 1000 and the topo showed up as being at level 1.

Have you got more than one topo and are placing points relative to one that is already there?

Nope just one toposurface. When I relocated the project, I went to an elevation view, selected Relocate This Project, and then moved it up a distance of 342.5 feet (which is finished floor elevation).

*edit* I tried making a level called Base Elevation at 0.0 (sea level) and then I created a new plan view based on that level. I then made another surface using an absolute elevation of 375, and it created the surface 375 ft. above the building and not above the base elevation level! :evil:

[patricks]

So I ended up doing away with any base elevations, and just selecting the entire model and moving it up 342.5 feet. Now the building sits on top of the topography as intended. Of course I had to adjust all the crop regions in my sections and elevations. I also no longer have the option of making the level elevations read 0.0 for finished floor if I want it to. It will only read 342.5.

But to me, it seems like I shouldn't have to do all this. In order to be able to switch your level line elevations back and forth between absolute or project-relative elevations, you have to use Relocate This Project. However, it would seem that topography does not work correctly if that is used. What is the consensus on this issue (shared project coordinates/location vs. topography)?

[iru69]

What is the consensus on this issue (shared project coordinates/location vs. topography)?
It's inherently confusing in my opinion (in the same way that Project North/True North is) - it doesn't work in an intuitive way that "architects" would understand. I may need to only set something like this up a handful of times a year, and even when I think I've got it figured out, by the time I use it again, I've forgotten how it works.

I hope the Factory understands that the architect doesn't always have all the topo information when first laying out a building, and Revit needs to be flexible enough to accomodate changes in elevation as more detailed topo information becauses available. While it may be more flexibility than I realize, it's not intuitive to me.

My 2 cents.

[patricks]

It's inherently confusing in my opinion (in the same way that Project North/True North is) - it doesn't work in an intuitive way that "architects" would understand. I may need to only set something like this up a handful of times a year, and even when I think I've got it figured out, by the time I use it again, I've forgotten how it works.

I hope the Factory understands that the architect doesn't always have all the topo information when first laying out a building, and Revit needs to be flexible enough to accomodate changes in elevation as more detailed topo information becauses available. While it may be more flexibility than I realize, it's not intuitive to me.

My 2 cents.

You are right of course, but in this case, I have all of the existing building and topographical information, as I have the original building's construction documents here as scanned images of the sheets.

The shared coordinates system is a good thing to have, so you can relate the building to the rest of the world, but it seems like that something like toposurface, which is obviously supposed to represent part of this earth, should be able to also reference shared real-world coordinates... but I guess that's something it can't do.

Yet another thing to add to the list of needed site tool improvements... although I'm sure it's already there.

[sbrown]

Ok, I'll see if I can clear this up.

1. Create your building at 0'-0" or 100'-0" whatever your office standard is. Don't worry about site or topo.

2. Now you get site data. Bring it in, create the topo surf. Again don't worry about where it is.

3. Once its created, move the topo to your building location.

4. Now set up the civil height. do this with the Tools/relocate project. From an elevation view click this tool, then move up or down as necessary to the proper elevation. Now you can modify your level tags to display either the civil elevation or your project.

In revit its allways easier to move the site, then the building. Now the only problem with all this is that as one post said, when you get updated site data from civil there is no way to automatically update. especially if you've spent hours spliting surfaces etc.

I hope this helps.

When you label your contours I believe you can set that tag to display either civil or relative too. Not sure on that one.

[jwilhelm]

creating a level at 0,0 and loading your survey file into it then create your site model and the contours should be at the right elevation, then build your floor levels relative to the site, this has worked ok fo rme

[patricks]

creating a level at 0,0 and loading your survey file into it then create your site model and the contours should be at the right elevation, then build your floor levels relative to the site, this has worked ok fo rme

Yes that's pretty much what I've ended up doing, but it would still be better to have the model relocated to shared coordinates. For one thing, you don't have to reposition all your elevation and section crop regions, and you also have the option of displaying level elevations as either relative to the project or absolute.

[Tobie]

I have done this before. Did the building and relocated it. Created the Topo end then moved it manually in elevation. the problem is that when you want to grade the Topo you have to work with the new level points.

[kparks140020]

The factory needs to address this issue as previously stated. I had a similar problem where a building was nearly completed before the topo info. was available. I did find that importing the DWG topo plan and positioning it in relation to the building was less problematic than moving the building. I did, for experiment, create a site.rvt file and imported the building.rvt and positioned it on the site plan. This worked well and did not change any building settings, but now I have two RVT files.

Just a question, is the factory developing a Revit Site package?

[patricks]

Just a question, is the factory developing a Revit Site package?

If they do, I sure hope they incorporate the tools into Building, because our firm quite often does our own civil site plan and detail sheets on smaller projects.

[shaunamorain]

Has this issue been addressed yet by Revit?

[Steve_Stafford]

I wrote a blog article (http://revitoped.blogspot.com/search?q=true+elevation) about this awhile back. The most flexible way (imho) to manage this stuff is by linking the building into a master site file. Set up your building project so it is easy to put on paper, project north is assumed by Revit in all plan views so don't worry about true north yet, or elevation for that matter.

Make a site project file and create your topography there at true elevations. To get contours to look right over scanned data you are going to need to add more points along each contour as well as fine tune the Site Settings. If you use an imported dwg file with 3D elevated contours Revit does a pretty good job of matching them, so you'll have to manually do the same sort of work to get the results over a scanned imaged.

Import/Link the building project file into the site file. It comes in at zero so you'll just move it up to the correct elevation in an elevation or section view. It is a trivial task to move a building when it is linked, much easier than doing this in the project file after you've gone "down the road" a bit. Not to mention repositioning it. Also move/rotate it according to your design intent.

Now you'll need to share its position in the site project with the building file itself. Select the building, edit properties, click Not Shared and click Reconcile. Then save the file and accept the prompt to save the changes to the building file as well.

When you reopen the building project file you'll find nothing has changed, or has it? Take a look at the view properties of the site plan and change Orientation to True North. If you rotated the building you'll find the rotation will change according to what you did in the site project.

Now take a look at the elevation and specifically the levels, edit properties and notice the Base Elevation parameters is assigned to project, change it to shared and you'll see the true elevation.

Hope this helps...even though its pretty late.

[shaunamorain]

Thanks Steve! :)

[Chad Smith]

However, it would seem that topography does not work correctly if that is used. What is the consensus on this issue (shared project coordinates/location vs. topography)?I haven't needed to use this tool until now and I have just spent the past hour doing my head in over this until I found this thread, and would agree that there is some kind of 'bug' involved. The topo is indeed taking on the coordinates of the 'Project' coords, and not the 'Shared' coords.

In fact, I would prefer the topo didn't move at all, when using the Relocate this Project tool.

Ed: Just playing around with this some more, and this is a major blow to this tool. I'm continually amazed at how much stuff doesn't work correctly in this software, while new features are still being added.

[Chad Smith]

This is a support request which I plan on sending off to Autodesk. Does it make sense, or have I just completely missed the point on how relocating a project works in relation to topography?


There seems to be a major flaw with a topography's reference datum. It is using the Project coordinate system instead of the Shared coordinate system.
The problem is, as soon as you "relocate" a project the topo moves too, and the readings of the topo's levels then become incorrect.

In reality, a topo is a FIXED piece of earth which cannot move vertically. The concept of relocating a project vertically, is to move it to a height which is relative to the fixed earth.

If for whatever reason users actually need it to behave this way, then that's fine, but at least give us a topo instance parameter so we can define which coordinate system the topo uses.

This problem really requires some immediate attention.

[chodosh]

yes and no, perhaps. here is the answer you will receive most likely: "relocate this project" does not discern between elements in the given file, it cannot discern the semantic difference between the building and the topography since the Revit "project" = the *.rvt = the database, etc. e.g. if the topo is in your active project file, your active *.rvt, then it will relocate with the building since it is all in the same "project." this is exactly why Revit recommends that you have a separate site file created from acquiring coordinates from the CAD file from the engineers, then link your building file(s) into that file, place accurately, and then publish coordinates to your file(s). i agree wirth steve's advice:

...Make a site project file and create your topography there at true elevations...
Import/Link the building project file into the site file. ..move/rotate it according to your design intent. Now you'll need to share its position in the site project with the building file itself.

[Chad Smith]

...it cannot discern the semantic difference between the building and the topography since the Revit "project" = the *.rvt = the database, etc. e.g. if the topo is in your active project file, your active *.rvt, then it will relocate with the building since it is all in the same "project."Revit already knows the difference between a topo and everything else, so would it not be a matter of when the relocation changes are made either in the current project or for a linked file, Revit is "intelligent" enough to know which objects to relocate?

The concept of having to work inside two different RVT files (building and site) for a single building project is just insane. Revit should be smarter than that.

Ed: If Autodesk do expect us to work from two files, then the current solution still causes too much confusion and can easily get users into trouble with incorrect site plans if they aren't aware or pick up on this. While Revit thinks it may be creating correct information from a programmers perspective, it is in fact creating visibly incorrect drawings.

[chodosh]

Revit already knows the difference between a topo and everything else, so would it not be a matter of when the relocation changes are made either in the current project or for a linked file, Revit is "intelligent" enough to know which objects to relocate?

You are theorhetically correct, however acknowledging that the term "Project" = the File itself, not a set of elements within any given file, instead what you are asking for is an additional tool within the Project to relocate elements by their mathematical positioning? That would be very nice potentially, although I am not sure how much more complicated we can make Shared Coordinates.

-LC

[sbrown]

The reason the topo is getting created wrong is due to the dwg import process. Before you create the surface move the dwg down, if you look at the dwg in autocad you will notice information drawn at 0 elevation as well as real elevation so what happens when you bring the topo in, is it places it like model geometry and if center to center is checked the link isn't going to come in the right z and needs to be moved up or down prior to creating the surface.

[Chad Smith]

The reason the topo is getting created wrong is due to the dwg import process.Not using a DWG import.

I'm just looking at this again this morning with a fresh head, and it seems everything is working fine. The levels, spot levels and contour labels all have a parameter to change between Project and Shared, the only problem is that the topo itself doesn't.
We need the ability to enter in datum based on the Shared coordinates, not Project. We shouldn't have to calculate a spot level height based on how far we have relocated the project.

[Chad Smith]

This is the example that I sent to Autodesk.

[Chad Smith]

So using this convoluted process, I have created a 'site' file and a 'building' file. The building is linked into the site, and the site linked into the building.

In the site plan all is good and I can work on my site based objects as such, but in my building model how do I go about labeling my contour levels of the linked site using the Label Contour tool? I have a few views in which I need to show this.

Switching constantly between the two files/models truly is a royal pain. Not to mention having to update the project information between the files as it trickles in.

[luigi]

I tried the process of having a linked file and a building...it is a royal pain to switch, especially if one needs to be unloaded before one can work...

But, Chad you are an advanced user, so forgive me if what I say you obviously know, I tried my best to understand the issues that have been recently raised (since the thread is old) but there are 2 flaws I see in dealing with shared/project and topography.

1. After moving project's elevation, one needs to immediately lower/raise the topography the same amount in opposite direction - minor nuissance
2. When the elevation is at the shared elevation, if one modifies the points it only gives you the options of project elevation, not shared - huge nuissance

Take care,


So using this convoluted process, I have created a 'site' file and a 'building' file. The building is linked into the site, and the site linked into the building.

In the site plan all is good and I can work on my site based objects as such, but in my building model how do I go about labeling my contour levels of the linked site using the Label Contour tool? I have a few views in which I need to show this.

Switching constantly between the two files/models truly is a royal pain. Not to mention having to update the project information between the files as it trickles in.

[chris.needham]

2. When the elevation is at the shared elevation, if one modifies the points it only gives you the options of project elevation, not shared - huge nuissance

Take care,

I agree, I've just come across this limitation in the last couple of weeks.

Surely the points can be shown as the shared elevation. We can label the contours as shared, so why can we edit the topo in shared coordinates?

[Chad Smith]

1. After moving project's elevation, one needs to immediately lower/raise the topography the same amount in opposite direction - minor nuissance
2. When the elevation is at the shared elevation, if one modifies the points it only gives you the options of project elevation, not shared - huge nuissance


I agree, I've just come across this limitation in the last couple of weeks.

Surely the points can be shown as the shared elevation. We can label the contours as shared, so why can we edit the topo in shared coordinates?

Exactly. With my discussions with Autodesk, they seem to think this is acceptable.

[Chad Smith]

OMFG, we just had an office meeting here instigated by the office manager (who doesn't use Revit) about levels and topos. The office manager and the rest of the users are oblivious to the underlying issue which makes this whole concept of moving a project flawed. I just wanted to stay out of this meeting, so I chose to keep my mouth shut, for fear or having to explain the details.
I'm not going to detail the ludicrous workaround that they have come up with, but it involves overriding intelligent data with dumb text replacements :roll:.

Autodesk, you HAVE to do something about this. Release a build which addresses just this if you have to. This is a major point to manipulating an entire building/site and it doesn't work. It comes close, but this one issue brings the whole concept to it's knees.

For anyone considering moving to Revit, take very careful note of this issue when demo'ing the software. It will cause you headaches too.

[Chad Smith]

I've also noticed that when a project is relocated, the contour labels don't represent properly anymore. They show the correct value, but are no longer located on the whole numbers, e.g. 1000, 2000, 3000 etc.

Is there a way to offset this problem, or is it another issue to add to the whole project relocation dramas?

I've tried explaining this to support, but they just don't seem to get it. Example RVT file attached.

[mruehr]

You can adjust this in Site Settings Passing Through Elevation Instead of 0.0 make it-153 or whatever the Difference
I really don't see the Problem with working in 2 Project Files The Site File and the Building file
you can open them at the same time with 2 sessions of Revit
the Trouble you had with the Topo is strange
we get here the Civil File and the 3D Polylines are at the Proper Height
so importing them center center then using them to make the Topo works fine for us
the editing is fine too as we work with real Heights and the Site File is in Project Coordinates and the Building Project in Shared coordinates
My sense with a bit of adjustment of your work flow this troubles should be easily overcome

[Chad Smith]

You can adjust this in Site Settings Passing Through Elevation Instead of 0.0 make it-153 or whatever the Difference.
This only adds more contours lines that go through the new offset value. The odd contour labels still remain visible. Screenshot attached.

I really don't see the Problem with working in 2 Project Files The Site File and the Building file
you can open them at the same time with 2 sessions of Revit
Because you shouldn't have to. This is an application where all the information is in one file. Not to mention the extra system resources you chew up when running more than one instance of Revit, and constant switching between the two files blows.
One problem with linking a site into your project is that you can't add contour labels on the linked topo in your project file.

[mruehr]

ah yes ... It does not when deleting the Additional lines in the Site Properties(which i have in my Template)

As for the Linking Guess it depends what kind of projects you do anything bigger than
a big Family house i would like to link anyway
Computers just seem not yet keeping up with revit(or Revit with multiprocessors)
and for scaling in to really Big Jobs there is no way around File Linking
Agreed we should have better interaction between Project and linked Files
but it got already much better than it used to be,my sense is there will be more development to linking just to provide Scalability

I see your Point as for my mind it works well the way it is

[Chad Smith]

ah yes ... It does not when deleting the Additional lines in the Site Properties(which i have in my Template)
Ah... gotcha. What a pain. This is something Revit should be adjusting for us when a project is relocated.


As for the linking. I totally agree separation is necessary for large and multiple building sites, but it shouldn't have to be so complicated for single building projects.

[tomnewsom]

Just a quick note - I always insert a 'Datum' level into my project, so that I can craete Existing objects with absolute height coordinates, and not worry abou them moving around if I alter the main project's levels.

[Andre Baros]

Fighting with this issue again after avoiding it for a while... but every project goes through this mess.
1. The linking option falls apart when you get into pads cutting things. Drives people nuts that the cut doesn't update until you edit the site file and when you're exploring options this is a problem.. we don't only work above grade. If everything was figured out and all we were doing was documenting the project we would be fine with multiple files, but we're not. The other issue is where to draw the line on elements in the linked file. Trees are hosted to the topo so you put them in the link, but what about the retaining wall, or the walkway that someone drew (as a floor) because they didn't want to take the time to open the linked file.

2. Elevation. Two concepts which work but are mutually exclusive. Pick your poison. If you work with absolute elevations than you draw a building at 345'-6" (or whatever) and you can accurately enter points for your topography using the absolute elevation function. This works, but you can't report shared elevation on your levels... our office standard is to have the first floor at 100'-0". The topo works but the levels don't. Poison 2 is to use the "relocate this project" shared level tools. You can work at 0' or 100' and have nice round numbers to work with, but then your topo points are useless. You have to do the math each time that you place a spot elevation. Both systems work, just not together.