Revit topo/Civil collaboration

[cliff collins]

Is anyone using Revit to develop grading plans, sharing with Civil Engineer,
and working back and forth from Revit to AutoCad, etc?

We develop a lot of prelim. site plans--usually starting with hand-sketches,
then clients need "digitized" version for marketing, etc.

We often receive survey info from Civil in AutoCad--hopefully with 3D polylines
for existing grading--which we then import and create toposurface from.

Our next step is to begin designing/developing new, proposed grading, building pads,
parking, roads, walks, etc.

Question: is it possible to alter the topo/grading in Revit, and then export out to AutoCad
with the resulting file having 3D polylines for contours? We have not attempted this yet--
but it seems that Revit will "smash" all info down to 2D upon export. It would be a great
feature if you could control the "smashing" process--and have Revit leave the topo in 3D
for use in collaboration with Civil Eng., etc.

Of course--we all need new/improved site tools--i.e. ability to model parking stripes,curbs/roads, etc. in 3D--i.e. follow slope of toposurface/subregions, etc......
hopefully 8.1 will address this. We would much rather use Revit for all of our site planning--
but often find ourselves falling back to 2D AutoCad--not where we would like to be!

Any thoughts on the site planning process would be of most interest.

cheers.....

[Steve_Stafford]

...Question: is it possible to alter the topo/grading in Revit...
Yes, but it can be time consuming. There is a grading feature that uses phasing to create a copy of the existing topo. Once the new topo is created you can change the topo points. When finished Revit will tell you the cut/fill when you examine the properties of the new topo.



...and then export out to AutoCad with the resulting file having 3D polylines for contours?...
Yes, you need to export to dwg from a 3D view to get 3D geometry. The contours will export to their own layers (with a 3D prefix) according to your site settings (primary, seconday contours etc). You'll also get a topo mesh.

As you say there are many wishes for additional improvements for site tools and we are all eager to see them.

[t1.shep]

Quite and old thread...but...
I'm trying to use a civil dwg file for creating my topo, as well as, showing other site elements, parking, streets, utilities, etc.
I've "imported" the civil dwg and unclipped the survey point and specified the coordinates at a given point on the survey. I then linked in a building.rvt model and placed/moved it to the appropriate location and published the coordinates to the linked building.rvt model. I then created topography from the dwg file. All is well.
Now changes were made to the civil dwg file (a road changed, a utility changed, etc., but the topo stayed the same.) I need to update the civil dwg, but since it was imported and not linked, I can't use "by shared coordinates". If I delete the dwg and re-import the file, it comes in to a completely different location.
I can just move the new imported file to the same location, because I can see the survey point, but I'm concerned that when I export out the building so that civil can place it into their drawing, it won't locate in the appropriate spot, which is one of the reasons for setting up the file this way. I'm also concerned that if the civil dwg gets updated a lot, eventually it could be placed in the wrong spot when it's re-imported.
How do you deal with this?