AutoCAD 2D Drawings to Revit via Dynamo – The Smart Way!

Even though the majority of users are now firmly engrained with Autodesk Revit software we still have to rely on AutoCAD for things such as Architects drawings, surveys and sometimes to interface with our favourite structural analysis software not currently integrated with Revit. Rather than recreating this data we can simply reuse this by reading BIM data from AutoCAD! So what is this BIM data from AutoCAD I hear you ask! In the case of a survey you have a wealth of information that you perhaps didn’t realise. The below Revit Survey was created entirely from the AutoCAD 2D survey. Note that some of the points may be slightly inaccurate due to the position of the text but still better that no 3D survey!

revit-survey-from-autocad-2d-drawing

Let’s take a look at the example below. Here you can see a typical 2D AutoCAD drawing representing a survey. We have the levels, information relating to trees, concrete bases, survey pins as well as areas of water. Of course this information could simply be linked into a Revit model as a 2D drawing but we would be losing quite a bit of information if we took this approach.

autocad-2d-survey

If you LIST or review the Properties of an AutoCAD object in a drawing such as a tree this is quite likely to be a Block. The block often contains attributes that we can utilise in Revit as BIM data. In the below example I have selected a tree. The Properties that I have highlighted are going to be used to recreate these trees. Notice that the canopy dimensions are controlled by the Scale; this is a fairly common practice.

autocad-block-and-attribute-properties

I have then typed the command EATTEXT (Enhanced Attribute Extraction) which will allow the end user to select the relevant properties and attribute values and write these out as a Microsoft Excel file.

Here is the Dialog that allows the selection of an entity or block. In this case I am extracting the block , PTS-047 which are the trees

eattext-page-3

I then select the relevant information that I require. In this case the Position (X,Y) and the scale (This is the canopy diameter) and the attributes.

eattext-page-4-selecting-required-properties

Here is the preview of the data prior to saving as a Microsoft Excel file. In this dialog you can drag the columns to new positions and suppress items such as name and count.

eattext-page-5

The data is now written to the Microsoft Excel file so that Revit and Dynamo can read this data and create the relevant objects.

autocad-extracted-data

In a similar way you can extract the text for the Level data and build a topographic surface in Revit. In the below image you can see the insertion point of the text as well as the Contents which will become the Z level. The trees are then placed as families which will automatically ‘sit’ on top of the topography.

properties-of-the-text-level

Here is the Dynamo Script to get the Topographic points from AutoCAD and create topography in Revit. It is worth noting that for those of you that have access to AutoCAD Civil 3D this can be achieved automatically. Note that I have split the image into two so that I could fit it on the screen!

dynamo-script-for-2d-levels-to-topography-part1

dynamo-script-for-2d-levels-to-topography-part2

Here is the resulting Topographic surface in Revit.

revit-topo

And here is the finished Topo with trees, slabs and sub regions imported.

revit-survey-from-autocad-2d-drawing

This workflow can be used for all manner of tasks. I do plan to create a full video tutorial if there is enough interest from the community?

Hope this is interesting,

LawrenceH

About lawrenceh

I am currently employed by Excitech, one of the largest Autodesk resellers in the UK, to provide training and other services such as implementation and project support to our clients. The main products I get involved with are Autodesk Revit Structure & Autodesk Inventor. My personal interests include aviation, engineering and walking.
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8 Responses to AutoCAD 2D Drawings to Revit via Dynamo – The Smart Way!

  1. Pingback: AutoCAD 2D Drawings to Revit via Dynamo – The Smart Way! - Revit news

  2. Pingback: Weekly Roundup – 2016.40 | The BIMsider

  3. Pingback: Weekly Roundup – 2016.40 - Revit news

  4. Plessey Mathews says:

    Lawrence,

    Excellent workflow. Hope you get the time to make a full video.

  5. bartosz says:

    Great work. Does Exitech do dynamo training?

  6. lawrenceh says:

    Hi, we do run a Dynamo course on a scheduled basis. If you visit http://www.excitech.co.uk and search for Dynamo fundamentals you will be able to see our syllabus.

  7. kieran atherton says:

    Hello Lawrence, i have an error as follows: ”Warning: No function called %get_Points on a Autodesk.DesignScript.Geometry.Point that takes __array could be found”

    Have you come across this before ?

    Thanks kieran

  8. lawrenceh says:

    Hi Kieran, I would have to see your script to find out why that error is occurring. Can you email it?

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