project elevation and toposurface

[Ning Zhou]

i created Level 1 whose elevation base is 0.0 for project and 100.0 for shared, and assume the real elevation of Level 1 is 100.
then i added toposurface using points whose elevation are all 100, i assume that toposurface will level w/ Level 1 instead of way top of Level 1, but it seems not the case (see attached rvt).
did i miss something here? looks like topo point elevation always "refer to" project instead of shared, shouldn't it be reversed?
i tried using rolocate project, also not work, i know i missed something here, very appreciated if anyone can give me a hint.

[Alfredo Medina]

I think the elevation of the topo points is measured from the project elevation. Therefore, topo points at 0' will be at the project elevation.

Now, when you add your Label Contour tags to the toposurface, click on the tag, then > Edit type > Elevation base > (select Shared). By doing this, the label contour tags will show the correct values of 100', 101', etc. as per your project's shared coordinates.

[patricks]

Correct. Toposurface points when editing the surface only display the project elevation values. This has been a long-standing issue with topo editing in Revit.

It can be solved by using separate site and building files linked together. The toposurface can be modeled using the real elevation points and then placed at the correct elevation in the building file, with the projects' coordinates shared between each file.

[d.stairmand]

If you look at the display when adding the points in it says "Absolute Elevation"
Project Based not Shared

[Gadget Man]

Correct. Toposurface points when editing the surface only display the project elevation values. This has been a long-standing issue with topo editing in Revit.

It can be solved by using separate site and building files linked together. The toposurface can be modeled using the real elevation points and then placed at the correct elevation in the building file, with the projects' coordinates shared between each file.

Although I really support the version with linked files and use it every day myself, there is a simple way to create it in a single file.

1) Create your DATUM LEVEL and name it something like "Sea Level" (in Australia is called "AHD" - Australian Height Datum) or any other name that you will know it's a DATUM.

2) Create your SITE PLAN based on this DATUM.

3) Create your topo in the Site Plan.

4) Create all your required separate levels for your building (Ground Floor, Top Plate, Upper Level, etc.) that are NOT based on Datum (Datum = 0!!!)

Then you have independent and true toposurface and contours and independent (should be locked together) building levels.

Really easy!

[patricks]

Although I really support the version with linked files and use it every day myself, there is a simple way to create it in a single file.

1) Create your DATUM LEVEL and name it something like "Sea Level" (in Australia is called "AHD" - Australian Height Datum) or any other name that you will know it's a DATUM.

2) Create your SITE PLAN based on this DATUM.

3) Create your topo in the Site Plan.

4) Create all your required separate levels for your building (Ground Floor, Top Plate, Upper Level, etc.) that are NOT based on Datum (Datum = 0!!!)

Then you have independent and true toposurface and contours and independent (should be locked together) building levels.

Really easy!

How would that work if you're already well into schematic design by the time you get your site survey? That's typically how it goes around here.

[Gadget Man]

How would that work if you're already well into schematic design by the time you get your site survey? That's typically how it goes around here.

Simply! CREATE a new level, call it DATUM and make sure its elevation is 0.00. You can even pin it and make it invisible, so nobody messes around with it. After all, this level NEVER changes, does it? Make it shared though...

Create view SITE PLAN view based on this DATUM (NOT Level 1 or Ground Floor or any other level).

Create site plan in your view SITE PLAN. I even go further and create EXISTING SITE PLAN and NEW SITE PLAN (for obvious reasons) - both based on DATUM LEVEL

Then all other levels can be moved independently of your DATUM and your SITE.

It really is very simple - I used to do it like that for years, before I convinced myself to linked files. I even teach how to do it at school and all other Revit teachers adopted this technique. It's a good technique for beginners, who are too "green" to comprehend linked files concept.

[Ning Zhou]

thanks all for your input

my issue here is when i create toposurface using points, i want to use "real" (shared) elevation instead of project elevation, for instance, points of 100.1, 99.2. 101.1, 99.3, i have to input as =100.1-100.0, =99.2-100.0,=101.1-100.0,=99.3-100.0, it's really stupid.

why Autodesk cannot give an option to use "real" (shared) elevation, or at least make it clear it's using project elevation when creating toposurface using points, normal logic thinking willl be using "real" (shared) as default because points info. is always from survey drawing

[Alfredo Medina]

I guess the only way it works as you want is when your project base point is at 100' and the levels of your project are actually at 100', 110', etc. Then you can have in your site your topo points at 100', 101.5' , etc.
Please see attached image.

[mthurnauer]

The one thing that I am not clear about is with the Datum method you suggest, are you saying that you could still have Level 1 indicate an elevation of 0'-0" even if its true above see level elevation is say 792'? or do the levels have to indicate their true above see level elevations?

[Alfredo Medina]

For this example I posted to work as shown the project's Level 1 elevation should be 100', and the Level family's Elevation base parameter needs to be set as "Project".

The other option is to change the Project Base point to 100', move the levels 100' up and set the Level family's Elevation base parameter to "Shared" so that it shows 100' and not 200'. Both options will let you work your site plans with the actual elevation of the topo points, as you want, such as 100.0' 101.0', etc.

Do you have 2011? I could post the same file back to the forum, with the changes.

[Gadget Man]

The one thing that I am not clear about is with the Datum method you suggest, are you saying that you could still have Level 1 indicate an elevation of 0'-0" even if its true above see level elevation is say 792'? or do the levels have to indicate their true above see level elevations?

That will depend what you want to show!

If you want Level 1 to show 0.00 whilst being on RL 120.00 you simply have to change the level line to project based.

If you want to show real RL you change it to shared. That is why you should make your DATUM shared...

If you want to show... BOTH (yes, you can) you can make the level line show the project based elevation and attach a spot elevation set to show shared value. Or the other way around - if you prefer that way... :) (see pictures below)