Aligning Revit models to DWG Surveys

[@b_gumm]

This covers everything you could need to know on the topic. A wealth of information here. Thank you for sharing with us.

[@AussieBIMGuru]

Glad it was helpful!

[@kaizhu6382]

Great tutorial and looking forward to the next one on Shared Coordinates.

[@AussieBIMGuru]

Thanks Kai! I've scheduled it for monday morning after next (july 22nd), had a lot of fun making it 😀

[@andretaylor7221]

I've been looking for this and I couldn't find anywhere else. You're now my Guru, many thanks! I'm in Adelaide by the way

[@AussieBIMGuru]

You're welcome Andre! Always great to hear from fellow Adelaideans, I sure miss its affordable real estate and rent vs Sydney's haha

[@pediaditakisminos4745]

Hey! Many thanks for your video. Concise, informative and the order everything was presented makes the subject well understood. A subject that confuses many people as you don't get to start new projects every day.

[@AussieBIMGuru]

You're welcome! Yep it seems odd that even 10 years since I learnt this I rarely meet even senior BIM managers that understand this workflow.

[@piotrchoromanski395]

Thank you very much. It effectively solves troublesome issues with CAD collaboration and data display in Revit.

[@AussieBIMGuru]

You're welcome!

[@victors.7717]

Thanks for sharing! Very informative and clear. Can´t wait for the next video "Shared Coordinates".

[@AussieBIMGuru]

Thanks Victor, glad it helped. Shared coordinates hopefully uploaded Wednesday after next, next week is dedicated to finishing off the Dynamo Learning series :)

[@daviddejesus4119]

Amazing cat mate, and amazing videos btw. Many thanks from Spain and thank you for sharing!

[@AussieBIMGuru]

You're most welcome! I actually have 2 cats but one is usually sleeping off video haha

[@romankh5338]

Great video. As a surveyor it’s always painful to see how architects butcher real world coordinates due to Revit limitations 😅

[@AussieBIMGuru]

Thanks! Yes Revit is far from a proper GIS software.

[@AnnikaMa-i2s]

Thanks finally I find your channel. It's a very informative tutorial. In the video you talked about survey alignment process to follow the steps - link survey - rotate true north -specify coordinated (by checking ID in dwg) - verify by checking other points. What would be the difference between acquire coordinates (from manage tab) after link survey in project file vs. above steps?

[@AussieBIMGuru]

Acquire coordinates suits some scenarios, but the difference is it establishes a relationship with the DWG link, whilst my method keeps it independent.

[@immi85]

Supper 👍 ( Can't stop watching your videos 😄)

[@AussieBIMGuru]

Glad you like 'em!

[@peterdallyn6440]

Great video really explains it how it should be done. I found that I needed to disable the save location in the DWG link otherwise the survey kept around when I set location by coordinates.

[@AussieBIMGuru]

Thanks, glad it helped! I think save location typically relates to shared coordinates so maybe you used acquire/publish as well?

[@desmondkipan2713]

Thanks for sharing.Very informative.

[@AussieBIMGuru]

You're welcome!

[@marwanbeaino5377]

The learning never ends with you Gavin ! Thanks a lot for this amazing tutorial !

[@AussieBIMGuru]

Glad you liked it!

[@just_a_statistic]

You are a life saver.

[@AussieBIMGuru]

Glad it helped

[@clomino3]

I'm working on a project in which I set up my project this way. The project I am working on, though, also includes a point cloud, which is geo-located. However, when I try to import the point cloud I get an error that says "The coordinates of the points in the point cloud file(s) you are trying to import are larger than 30000. Importing the file(s) may result in undesirable graphic behaviors. Click Yes to continue." So essentially, it is doing the same rounding on the point cloud as it would do if you were working 20 miles from the Internal Origin. It results in the point cloud being off. Any ideas on how to remedy this? My only thought is dropping the real-world coordinates and setting the Survey point as 0,0 instead of whatever the real-world coordinate would be. Thanks for these videos!

[@AussieBIMGuru]

Yep I nearly always have to get an 'originated' point cloud set up versus real world coordinates from surveyor for this reason. It's a fairly jarring limitation of Revit given the shift towards GIS.

[@gpiassum]

Hi, I couldn't find a solution when I do link revit and the models are not in the same coordinates. Do you have some video about it? Thanks

[@AussieBIMGuru]

In this case you would probably want to use shared coordinates to resolve this issue. I have a tutorial on this topic in my revit playlist. You could also manually align the models by ensuring their rotation to true north matches, then aligning their project base points and ensuring they have matching N/E values.

[@anandjain6779]

Sir , I have major confusion here , If we can Directly Acquire Coordinates from the linked Arch OR STR file then whats the purpose of linking this cad Survey file in revit ? Just wanna override this confusion

[@AussieBIMGuru]

This is moreso a guide for the architect or engineer who has to do it first! From there you could acquire, but it's always wise to let your team know as shared coordinates will need to be used by all the consultants if done properly.

[@slevinkalevra]

Awesome!! 🙌🏻🙌🏻

[@AussieBIMGuru]

Glad you liked it!

[@nebiatsentayehu5303]

Thanks, Aussie so help full

[@AussieBIMGuru]

You're welcome!

[@charlesball9522]

Why would the manual placement options not be available? I only have three automatic options.

[@AussieBIMGuru]

Hrm I'm not sure to be honest. I tested a variety of view and link types and could always see the manual options. I haven't tested on BIM360 though, wondering if maybe these options are limited there or if it might be Revit LT?

[@charlesball9522]

@@AussieBIMGuru We are using BIM 360. But it's full fat Revit.

[@AussieBIMGuru]

Had a look in BIM360 but I can see all the options there to - stumped on this one!

[@ssnanj8014]

Great Video. . do you have videos explains for Position ?.

[@AussieBIMGuru]

Not for the positioning options in detail, but I discuss positioning a bit more in my shared coordinates video also.

[@ssnanj8014]

@@AussieBIMGuru Thx. i will go thru it. we wish to know more detail about each option in position also in coordinates. in any chance , kindly have video for that.

[@AussieBIMGuru]

@@ssnanj8014 this is more of a fundamentals topic, I tend not to cover these as there's lots of material out there for them. RevitPure and Balkan have some good videos on these, maybe try them out.

[@ssnanj8014]

@@AussieBIMGuru Thx

[@TheBIMCoordinator]

Great info!

[@AussieBIMGuru]

Thanks! A rather tricky topic to cover...

[@TheBIMCoordinator]

Aussie BIM Guru i understand I always reference Paul Aubins course, now I have a new resource!

[@AussieBIMGuru]

@@TheBIMCoordinator Ah yes Paul Aubin's tutorials are decent. I figure this is probably a more consolidated take on it, so glad it will help. Coordinates are one of those things that I feel I relearn each time I set up a project that relies on them!

[@drvlive2023]

What's the difference of placing the coordinates, and highest spot elevation at the Survey Point?

[@AussieBIMGuru]

Ultimately it's all relativity. Internally, the revit origin is what matters most. Given most projects are surveyed relative to 0,0,0 usually I make this the survey point so my coordinates can be relative to it.

[@drvlive2023]

@@AussieBIMGuru this topic is so new to me, that I do not know how to respond. I don't even know if I am asking the right questions. Anyway, do you have videos related to working on the revit topography, lke placing buildings or masses in particular? Since they're only possible only if hosted on building pads

[@AussieBIMGuru]

@@drvlive2023 I guess simply what I mean is that the survey point represents what you want it to. It can be a survey datum at a known coordinate (it doesn't have to be at 0,0,0) or it can be an absolute origin (0,0,0). Try not to let Revit dictate how you use the program. At the end of the day we can tell it a lot of things too I have a series on feasibility, but it doesnt go to the point of generating detailed topography/pad elements. I find the site tools in Revit quite limited, can't do much more than the fundamentals. Might be worth seeing what Balkan Architect has available in this case, he does a fair bit of topo.

[@drvlive2023]

@@AussieBIMGuru I am trying my best on not being dictated by Revit. A lot of my knowledge in Revit came from Balkan, I've subscribed for like 2 years already. You did a good explanation to this anyway. Hope to see more. Thank you!

[@jaroslavjelinek428]

12:24 Extent Issue 13:40Survey Alignment process

[@AussieBIMGuru]

Thanks for the timestamps!

[@DeansFork]

At project setup, is there any downsides to moving the PBP to a point on your MGA survey (e.g. N/S6240000 E/W 330000). Keeping the survey point at the 0,0,0 origin and linking the CAD file by shared coordinates? I find this then allows for linking of pointclouds and cad files to correct real world positions. Thanks for the great video 👍

[@AussieBIMGuru]

Yes the main issue is if those coordinates are well outside revit's geometry truncating limit of about 10 miles. This is quite common as MGA points arent usually that close to a site.

[@DeansFork]

@@AussieBIMGuru Isnt the 10mile truncating limit based on the internal origin location? As opposed to project startup xyz0,0,0?. If you move internal origin then you're moving the truncating limit with it. Also when you say truncating limit, do you mean when geometry starts to distort and misbehave when too far from internal origin? Or does it have any other effects to the model. Thanks for responding 😎 your channel has helped me alot with dynamo 👍

[@AussieBIMGuru]

Internal origin is effectively project startup point. It never moves, only Project base point and survey point do. Truncating is generally the misbehaviour like you mentioned, but can also cause issues when exporting back out as well.

[@DeansFork]

@@AussieBIMGuru I see, but if you do following: Manage > coordinates>specify coordinates at point>enter mga coords. I thought this moved the both the internal origin and pbp, I must be mistaken.. I've never had any truncation issues doing it like this before but was interested to see if it could cause any issues as it differs to your approach. Thanks again. Look forward to your next videos ☺️

[@AussieBIMGuru]

@@DeansFork this only moves the relative coordinate system (PBP/SP values), the internal origin stays at 0,0,0 in Revit still. You can verify this in Dynamo by making a point at the origin and it will be at the internal origin every time.

[@iftekharkhan8879]

Hi sir how r u ...sir while rotating true north ...i saw some people subtract the angle from 360 then they rotate the resultant i.e 360- angle ......i don't know what's the trick ...can u plz tell me .....thanku sir...

[@AussieBIMGuru]

It really just depends whether you want to rotate to the left or right (anti or clockwise). Some people prefer to work consistently, so sometimes they may know the angle but in the opposite direction to what they know. To calculate this they can enter their angle as a temporary formula for revit to solve (360 degrees minus rotation angle).

[@luisarias9682]

Do you have these slides as pdf handout?

[@AussieBIMGuru]

github.com/aussieBIMguru/Presentations_PDF/blob/master/ABG_190708_AlignToSurvey.pdf

[@iftekharkhan8879]

And i saw sometimes people use aquire cordinate frim cadd file to set dwg surveys is it correct??

[@AussieBIMGuru]

Not usually. Unless you have a strong understanding of how the UCS/WCS are set up in the AutoCAD file it is risky.

[@KusKanat]

Thanks allot!

[@AussieBIMGuru]

You're welcome!

[@arkplato2186]

I have downloaded two Autocad files from the govt. database. One contours to make toposurface later from it and the other siteplan with building footprints on it. The problem is that although I could easily overlay them perfectly in Autocad I cant get them align properly in Revit. No matter what I do. Both are dxfs and I have tried with dwgs also. But they wont just be correctly aligned in refernce to each other.

[@arkplato2186]

Please help me to how to get them correctly in revit.

[@AussieBIMGuru]

@@arkplato2186 move their contents close to the autocad origin to make sure their file extents isnt too large for revit to accurately represent. If they arent aligning in revit, find at least two common points between the files (or make them in autocad) and use these to realign the files in revit as a last resort.

[@arkplato2186]

@@AussieBIMGuru Okay I found out that the only way it works is if I insert first file by using manual origin and then acquiring cordinates under manage. then while inserting the second autocad file I have to use shared cordinates option then it does overlap perfectly. Please help I found this work around but not the explanation as to why this is happening.

[@AussieBIMGuru]

@@arkplato2186 the most likely reason is there is a WCS setting in the CAD file that is acquired as a coordinate system in revit. By loading the second file using the same system it understands their relationship as theyre probably using the same WCS or UCS.

[@mauriciopalomares4010]

Thanks GURU

[@AussieBIMGuru]

You're welcome!

[@pedrobicycle6521]

*Map* Grid of Australia (MGA). 👍

[@AussieBIMGuru]

Yep good catch!

[@iftekharkhan8879]

Hi sir how r u ...sir i want a cad file that has world cordinates basically i want to learn myself on a project that has a site plan and with real world cordinate system by this i can learn how to set cordinate in revit ... If u have that file plz send me ....thanu very much ....

[@AussieBIMGuru]

Unfortunately I don't have such a file, and dont believe one would be possible to create. The world is huge, usually on most projects coordinates are relative to datum local to the country.

[@Jyroskope]

So you are actually supposed to first Specify Coordinates at Point at the Survey Point and not the PBP? 😅

[@AussieBIMGuru]

You can do either one, it depends on what information your survey has provided. The common thing is specifying one coordinate with known values after rotation of true north.

[@many_worlds]

you have a nice cat dude

[@AussieBIMGuru]

Haha thanks!

[@rezwanulhoque117]

WHAT IS THE MEANING OF INTERNAL ORIGIN IN REVIT ?

[@AussieBIMGuru]

This is the origin of the Revit model itself. The project base point and survey point are extra points that can create a coordinate system relative to this. Autodesk has a detailed summary of it here: help.autodesk.com/view/RVT/2022/ENU/?guid=GUID-363D008B-69DF-4FAA-AA01-6BE9C10267A8

[@rezwanulhoque117]

@@AussieBIMGuru THANKS.

[@nikouer]

I think you made things too complicated in this video. A topo model with big coordinates normally uses a projected coordinate system. As an architect its usual not to have knowledge about that but you must know one thing. Project coordinates systems have scale transformations. You cannot design a building right away using them. When you design a building you must ask from a surveyor to convert these coordinates to a local site appropriate for building design. The transformation is not just a move. In small sites, many times it's not noticeable. But in large sites it is.

[@AussieBIMGuru]

Thanks Nikou, I understand that a survey can often be a more complex process than what I showed here, ideally this process would be applied once a corrected coordinate system/survey reference is provided for alignment. I would hope in this circumstance the surveyor is more actively involved in guiding this process for the users given high level of risk involved in discrepancy. At the end of the day architects rely on the expertise of their surveyor to provide true and correct data to align towards, it is not our job to dictate this process. The case study I used here is quite typical of working with Australian coordinate systems provided by surveyors, I expect different projects/areas of the world differ depending on location and model use (different GIS/GDS types etc.).

[@nikouer]

@@AussieBIMGuru i think in your example also needed to applyed a combined scale factor before insert in Revit. Also one suggestion. I always create a level without view, witch I call sea level. It remains at the 0 elevation is Revit internal origin. I always attach survey files at this level because topo points also work with absolute elevation. Then I move my project Base point in the elevation certificate want to have my project 0

[@AussieBIMGuru]

Yes this is essentially how I manage things now also, a datum level. I typically give it a unique level type and filter it out.

[@drbrendanful]

This is a crap explanation

[@AussieBIMGuru]

Sorry you feel that way. It's my general approach to this day and has worked for me on many projects. Turn your feedback into constructive action - make a video and show me/others how it is done 😉