Creating 3D Models From 2D Floor Plans: Part 2

In my last post, I began a series of posts that was going to create a 3D model from a 2D floor plan.  The floor plan is also going to be compared to a 3D scan to verify the accuracy of the 2D floor plan.

The first portion of the workflow was to take the facility scans into ReCap to create a 3D Point Cloud.  Now that we have done that, we are ready for Phase 2, which is building the Revit model on the 2D floor plan.  One key element to the whole workflow is making sure that the Point Cloud and 3D model have a common origin.  We set the origin in the ReCap model, so we just need to make sure that we have the same point as the origin of the AutoCAD file.  The origin of the AutoCAD model will be connected to the origin of the Revit model.  The standard AutoCAD move command can be used to move the entire floor plan to the origin, if it is not already in the correct location.

Now we are ready for Revit, so we can create a new Revit model, from an Architectural template.  The AutoCAD file can be inserted as a linked CAD file.  Then the AutoCAD file can be used to snap to as walls, door, etc are added to the model.

The following video shows how to move the desired AutoCAD point to the origin, insert it into a Revit model, and create the building architecture from standard Revit workflows.




Once the Revit model is done, the next step it to connect the Revit Model to the ReCap model.  There are two ways to do this.  One is to insert the ReCap model into the Revit model.  However, there is a ReCap Beta function that I want to show off in this workflow, so I am going to focus on the second method.  The beta function that I want to show allows the user to overlay a Navisworks project over the scan image in a 3D view.  Again,  this requires a Navisworks file, so my next step will be to append the Revit model to a Navisworks model.

There is not much to appending a Revit model to a Navisworks file.  It really is just a matter of clicking the Append command and picking  the Navisworks file.  Navisworks will insert the model origin to origin, thus the earlier importance of getting the AutoCAD file's origin to the right place.  There is one tricky point to the Navisworks portion of the workflow.  ReCap wants an NWD file, not the typical NWF file.  The NWF file mostly references other files, the NWD will contain all the model geometry, which ends up being easier for ReCap to overlay.  One downside to the NWD file is that it will not update dynamically.  So as the Navisworks model changes, you will need to export another NWD file.  Creating the NWD file is pretty simple, it is just a matter of performing a Save As of the Navisworks model.

Once you have the NWD file, it is time to attach the file to the ReCap project.  The attachment of the NWD file is done through a command from the menu in the bottom right corner of the interface.  All you have to do is click on the Attached Project command and pick an NWD.  It can be confusing at times because you really will not see the project change after the file is attached.  That is because the overlay occurs only in the RealView, which allows the user to look at the actual scan image.  However, if the project attached successfully and you enter a RealView, from one of the scan locations, you will see the Navisworks project overlayed with the scanned image.

Here is a video that demonstrates the workflow of taking the model from Revit to Navisworks to ReCap.


The benefit to this is that it should be easier to visually compare the ReCap to the Revit model.  If any discrepancies are found, the user has a pretty good idea of what portions of the facility need to have some measurements taken.

In my next post, I will discuss how to correct some of the discrepancies between the 3D scan and 2D floor plan.