Ideas for Landscape Architecture Toposurface Modeling?

[Anonymous]

I work for a landscape architecture firm in Montana and we are somewhat new to Revit. We have found Revit very useful in creating models for showing clients spacial relationships of sites etc. but we're still finding the workflow clunky. All of our surveys come through AutoCad where we also do all of the grading design. These are often steep, complicated slopes where we need to add walls and graded areas to make driveways and building sites work. When doing this in AutoCAD we often use curved polylines to show modified topolines in graded areas, but we quickly realized that Revit will not read arcs in topography lines. So we are having to go through and make straight line segments that will work for the model. In addition, we are finding that in order to make a "graded region" from existing survey to modified survey, the have to go through each contour and splice out the existing topo line where it is being changed for the modified site survey. A process that is tedious and slow at best.

I have found very little useful information about the Site Designer plugin but am open to any tips on how to better use it. That being said, we would like to continue to use AutoCAD for the grading design and just use Revit for modeling purposes.

I'm curious if there are other LA's out there who are willing to share ideas about how to simplify our workflow or talk about their approach. Thanks.

[SteveKStafford]

I'd recommend getting acquainted with Lauren's Landarch BIM site/blog. She works in your field and has been expanding on her use of Revit for her work and documenting/sharing things all along.

[Anonymous]

Thanks for the reply, Steve. We paid for the landarchBIM course and have worked our way through it. It was very helpful in getting up to speed on Revit basics.

We're having trouble finding more content about working with grading design. It seems that most instructional/tutorial videos use topography in very loose terms. Push here, pull there etc. For us, every 1/10th of an inch matters which is why AutoCAD is our preference. 

[barthbradley]

---

@Anonymous wrote:

every 1/10th of an inch matters which is why AutoCAD is our preference. 

---

1/10 of an inch!  Holy cow! Are you grading ant hills?  Ha! 

I have a questions regarding your Arc comment and how Revit won't recognize it. Why can't you convert it to polyline?

[Anonymous]

For example, if we are designing a driveway with multiple switchbacks and changing grades (switchbacks at 6% and straight runs at 9%), 1/10' over 200' will add up to a significant amount of elevation difference. Imagine a mountain side with a building site 50' below the road on a 20% avg. slope. 

As for the topo lines, we can convert them to a polylines but in order to make it look smooth (correct) we end up having to trace the arcs by hand to create segmented curves. It's the splicing out the underlying "old" topography that gets to be tedious.

[Anonymous]

I did mean 1/10th of a FOOT. Thanks for pointing that out.

[barthbradley]

I spent most of 2000 decade doing what your are describing.  Plot Plans and Driveway Geometrics.  Arrgh!  

Regarding having to trace over the polyline that's been created from an arc line; I don't understand you would need to that. Maybe, I'm misreading you, but aren't you imported the dwg into Revit and creating a Toposurface from the Import Instance?   

[Anonymous]

Yes, we're doing exactly what you described, importing the .dwg to create the topo from the import instance. All of the surveys we get are plotted in straight line segments. When we import a survey to Revit with topoline adjustments using polyline arcs, the mass will just leave a gap (interpolating points) in the toposurface wherever there is an arc. However if we replace the arcs with straight lines, it works perfectly. And if we simply convert the arcs to eliminate the curves, we lose any sculpting of the landscape. Are we doing something wrong with the import? I'd love it if there was an easy solution to this. Thanks for your reply. I'm glad to have found another person who understands what we're trying to do.

And for what its worth, we use the arcs for the topo lines because they are quicker and more accurate in AutoCAD over large areas. But now we are re-thinking that time tested strategy.

[ToanDN]

If you use a point file generated by a civil engineer program such Civil3D to create the topo then you may not have the same problem.

[Anonymous]

The surveys we get have the TIN file included. The problem arises when we're doing the actual grading design in AutoCAD. When we move to Revit, we first create a topography of the "existing site" survey file, then use the graded region to overlay a "new" topography with the design changes made in AutoCAD. 

Investing in Civil3D would probably solve the problem but would also come with it's own can of worms/headaches.

[barthbradley]

If you want, you can post one of your dwg files.  I'll take a look at it and see what I can suggest as a possible Revit workflow.

[ToanDN]

What I mean is create the topo from the point file and do all work: splitting topo, grading regions, site padding, etc.. in Revit. You can still use AutoCAD to draft a site plan and link to Revit (as 2D plan) for reference to do the above work.