import 3D dwg - convert to topo surface

[trombe]

Hello,

I have come across a problem not encountered before with (simple) 3d dwg Surveyor files.
I have a shadow analysis job as separate consultant ( to a Vector Works user).
I have been handed a 3d dwg Surveyor file.
When selecting Site tab - Toposurface - use imported - import instance, select the dwg file and hit the go button, Revit freaks and an error message comes up with a note about some data is out of range.
Revit will not convert the dwg file into a Revit toposurface.

Can someone please advise the wider / complete description of the range issue and if there is a way to overcome the problem ?

I am having to model the toposurface manually due to time constraints - there is not time to go back to the Surveyor to seek further information or get a restricted range file sent or to seek an appropriate points file.
In other times, I have had to cut off bits that the Surveyor file contained to get what is needed, however in this instance....Revit will not even generate the toposurface.
thanks for any help on this matter.
regards
trombe

[Max Lloyd]

maybe you can post the dwg file to see if I can convert it for you?

Max

[trombe]

Hi Max,
thanks heaps for your offer.
here is the file.
I was also handed a 2D dwg Surveyor file with considerably more data and originally tried to convert that file assuming it was the 3d data file, but of course Revit just flattened it out and made it look cute ......
Good luck. Can you post back here with the rvt or mail me private as you choose.
thanks again for having a go.
regards
trombe

[Mike Sealander]

The out of range data is literally that: there are some points in the file that are beyond the file's limits settings. Grab the points you need and make a new file, and use that. In my experience, the out of range issue stems from the way surveyors use 0,0 (which might be a USGS datum several miles from your site), but still contained in your file.

[Teresa.Martin]

Dear Trombe;
Just to clarify, you need to move/change the base point in the Autocad file. Generally I draw a line from the 0,0 point to the existing base point. I then relocate (move) the file to the 0,0 point. In this way you always have a line demarcating the previous base point and the new base point. You should then be able to link in the civil drawing without issues.
Best regards,

[erictsn]

Dear Trombe

I don't know the below threads can be helped you for solving it.

Collaboration between Revit Architecture and AutoCAD Civil 3D
http://www.blog.cadbeyond.com/?q=node/215
Create realistic surface
http://www.blog.cadbeyond.com/?q=node/158

Best regards,
Eric TSN

[trombe]

Dear Trombe;
Just to clarify, you need to move/change the base point in the Autocad file. Generally I draw a line from the 0,0 point to the existing base point. I then relocate (move) the file to the 0,0 point. In this way you always have a line demarcating the previous base point and the new base point. You should then be able to link in the civil drawing without issues.
Best regards,

Thanks Teresa.
Sorry but I do not have a clue what you talking about !!
I used to use AutoCAD LT prior to starting with Revit 4.5, and I do not have AutoCAD, or access to it. I have seen the David Conant post about the approximate location of 0,0 in Revit as being approximately in the centre of the default template elevation view icons. I would not know where to start looking for an origin of a .dwg surveyor file and generally, neither would know what program it was created in, nor actually, would I want to know.

I simply need / want to use the Revit option to create this toposurface mostly because, I have to analyze (and usually create a series of glass planes vertically and at various inclined plane values) on the boundary line to check the local authority limits for breaches of the recession planes / sunlight access planes (SAP).
I also use this toposurface in connection with sunlight analysis for client and other / adjacent buildings and land.

Sorry, how can I find the origin of the imported or linked .dwg file and do you know of a way to precisely locate the Revit origin that is more descriptive than David Conants description ? ( not being flippant and David Conant is always very generous with his advice anyway).
thanks for any step by step advice.

regards
trombe

[SkiSouth]

Trombe.
Surveyors in Acad usually use a defined point in their working area, whether or not it is related to the site surveyed or not. For example, the surveryor has to do a survey. He has an overall known point for the survey back at the entry for the subdivision. A mile down the road is the plat to locate, topo etc. The 0,0 of the survey might be the known point a mile down the road, but using autocad, the survey would look normal, as there would be a window around only the survey you ordered.
The fact the drawing was so large (in 3d space area) was giving Revit a hard time.

This survey was located 399323,5550, 7988801.3466,143.00 away from the 0,0 in autocad. Moved it in Autocad and saved it then it imported into Revit 9.1 fine. I'm having issues with the display of the toposurface on my monitor, but attached is the file created. - warning - it is an imperial template based file. I also assumed the file was in feet (when creating the Revit file) so the actual rvt file posted might not help if my assumptions are incorrect. However, the moved autocad file is also posted. Hope this helps.

edit -also, if you import the dwg file, leave it as a complete import (don't explode it) , then under site select Toposurface, then use imported, instance, then I left ctrs major and ctrs minor layers as the only points to consider.

[David Conant]

You don't have to move anything in the dwg as long as you place the dwg in Revit so that the survey data is located near Revit's origin (precise location is not important here).

For this reason, don't an do origin to origin import. Import center to center instead, then move import so that your building site is near the elevation markers. Finally, the top of the starting Revit view will be your Project North, so rotate the dwg to orient it correctly with respect to project north. (North on the survey will now be at some angle.) Use Acquire Coordinates and select the dwg. Revit's shared coordinate system will now be the same as the dwg's but Revit's working coordinates will stay within the range that works well for Revit. Project North will be convenient for modeling while the survey's north will be understood as True North.

[SkiSouth]

The fact the drawing was so large (in 3d space area) was giving Revit a hard time.
.
So David, Am I wrong on this, or just taking the wrong approach or both?

[Martin P]

You don't have to move anything in the dwg as long as you place the dwg in Revit so that the survey data is located near Revit's origin (precise location is not important here).

For this reason, don't an do origin to origin import. Import center to center instead, then move import so that your building site is near the elevation markers. Finally, the top of the starting Revit view will be your Project North, so rotate the dwg to orient it correctly with respect to project north. (North on the survey will now be at some angle.) Use Acquire Coordinates and select the dwg. Revit's shared coordinate system will now be the same as the dwg's but Revit's working coordinates will stay within the range that works well for Revit. Project North will be convenient for modeling while the survey's north will be understood as True North.




That is an excellent tip!!! :)




a huge cloud of not quite understaning how to use project/true north and DWG files has just lifted. I really didnt realise that I could use a rotated, DWG file that was imported as centre to centre to centre then moved and still manage somehow to aquire co-ordinates from it! I cant wait to do this, that is the best Revit tip I think I have ever read.

I can now just put setting out co-ordinates right on my foundation plans!!



Thank you, I am off to play around with that!! :)

[Martin P]

ummmm the big confusion cloud is back, it still doesnt work the way I thought it would after reading davids tip - It gets the true north bit right when I aquire cooridnates from a linked dwg file - but the actual coordinates are all completely off in the revit file? - they are correct in the DWG file, it is linked at the correct scale. The DWG file is set to world cooridnate system - I just dont understand what I have missed here, is it not supposed to just take the co-ordinates from the linked DWG file as well as true north when I aquire cooridnates?..... it does not do that. Afraid I am still not at all understanding how to get a coordinate sysyem to work between Revit and DWG files :(

Can anyone help out? Would love to do it as easily as described by David if you can....

[David Conant]

So David, Am I wrong on this, or just taking the wrong approach or both?
If reasonably centered, size is only a limitation if actual dwg geometry extends more than about 2 miles/3 km from the center.

[Teresa.Martin]

Dear David;
While I agree with you in principle,
general practice, at least in the firm's I have worked in, is to still move the site closer to 0,0 (via xref or whatever in Autocad). I have found that if the site in the Autocad file is really far from 0,0 in Autocad that when you bring it into Revit you get this double line affect. It is this weird thing that happens. It appears as if the dwg file is stretched. Moving the civil drawing to the origin in Autocad fixes this issue.
Best regards,

[trombe]

[QUOTE=Skisouth]Trombe.
abridged

This survey was located 399323,5550, 7988801.3466,143.00 away from the 0,0 in autocad. Moved it in Autocad and saved it then it imported into Revit 9.1 fine. I'm having issues with the display of the toposurface on my monitor, but attached is the file created. - warning - it is an imperial template based file. I also assumed the file was in feet (when creating the Revit file) so the actual rvt file posted might not help if my assumptions are incorrect. However, the moved autocad file is also posted. Hope this helps.

Hi Skisouth,
thanks for the info so far.
I could only get the import to work when meters was selected as the import units.
I personally work in millimetres.
Yes I got that about not exploding. I had found this out the hard way a while back !!
The file import bought Revit to its knees BTW, everything slowed down radically, but my system is end of life and about to be replaced.
thanks and I look forward to further information about this
regards
trombe

[erictsn]

I do not exactly know what happen of the original file; I use "wblock" command and create new dwg file. And use the meter units.

I do not move the cad file to origin 0,0; so it would move to centre-to-centre in Revit after link. After link It can use "Publish coordinates" to move to original coordinates.

Step in Revit
New project (metric) --> Link CAD format --> Click North view --> Copy elevation line to proper elevation --> Generate Topo surface

Did I make the right procedure?