poor graphics performance in Navisworks

I found a great post the other day from Beyond Design that I thought I should share.  This is from 2011 but if you are experiencing a sluggish Navisworks some of this may be helpful.  Specifically the part I am interested in is below but the whole article is here.

The Model

Is it detailed? Is it large? How many triangles, you can find out under Project > Scene Statistics, compare this to what your card can handle? Models with lots of curves require more triangles, just get a piping model and switch to hidden line mode; you’ll see that this can build up quickly to create thousands and millions of triangles that need to be drawn. If you reduce the faceting factor (Options > File Readers), when bringing the native CAD file in, then this will reduce the number of triangles we use to draw the rounded item, lower it too much though and the item may look blocky, the default is set to 1.

Are there any parts of the model a long way away? Do a quick audit of the model by seeing if Zoom All zooms so far out you can’t see the model you expected. Use the Selection Box tool to work out what is distant from the model and see if you can change in the native application, if not then Hide it.

If you have set lots of the model to be required (i.e. prioritized when you are navigating) then you may experience lots of drop out of all the other items. Again, start from nothing (right click > Reset All > Unrequire All) and slowly build up adding those essential items.

Try running the model with ‘Scene Lights’ Lighting and ‘Shaded’ Mode on the Viewpoints tab, if this significantly improves performance then you might have over done it on the materials and lighting. Look at using the materials and lighting you need rather than going overboard and adding materials and lights to everything.

working with revit & navisworks

Collaborating with Navisworks can be a great way to communicate with all the project partners, it can also create some headaches.  As collaboration gets more and more detailed each discipline needs to better understand the other disciplines and their working requirements.  (This makes any employee who understands more than their isolated discipline a much more valuable  asset!)  One workflow is to have both Revit and Navisworks open and to co-ordinate geometry by exporting NWC files from Revit and updating the Navisworks model.  In order to be effective and productive this has to be done as efficiently as possible, I am currently attempting this workflow only to be ground to a halt for 6-8 minutes every time I refresh my Navisworks file.  Although to be honest it is giving me both the impetus and the time to write this entry Smile  So let’s go over a quick how-to for using Revit and Navisworks to help speed the process up.

What to Export

Always export only your own information!  I can not emphasise this enough – everyone else is going to do the same so if you are the electrical there is no need for you to include the architectural model.  As an example, the electrical model would look like this

    Screen Shot 04-10-15 at 02.48 PM

So make an isolated 3D view (good practice is to name it “Navis” more on this another time) and go through the Visibility Graphics settings and turn off everything is not directly your own responsibility.  There is a quick category caveat – family elements set to generic or speciality equipment may be from many different disciplines, think about editing them to make your families your own discipline or use VG filters to isolate your own.

HOW to Export

During the export to NWC there is a place to choose the Navisworks Settings…

Screen Shot 04-10-15 at 03.08 PM


My settings look like this

Screen Shot 04-10-15 at 03.11 PM

convert construction parts: unless you are the GC you likely don’t need to use this

convert element ID’s: this is the unique identifier for each element it could be left on

convert element parameters: Basic Revit properties will be included in the Navisworks file regardless of this setting.  Checking this box will do 2 things during the export process:
1.  Additional properties will be included with the resulting Navisworks file.  These include properties for Navisworks related to the element properties, object orientation, material information, associated level, worksharing information, family specifications, cuttability and Revit object category.
2.  Depending on the size and number of objects in your project, the export time can dramatically increase as additional properties will be translated.  For example a 100 MB file with this unchecked may take a few minutes.  Check the box and the export time may jump to 20 minutes.  This is something to keep in mind if you don’t need the additional information in Navisworks. – PLEASE PLEASE UN-CHECK THIS




convert element properties : consider not including these (see above)

convert linked files: please don’t include

convert room as attribute: unless you are the architect this is not required

 convert URLs: will include any URL’s associated with families

coordinates: this depends on the project specific settings

divide file into levels: helpful as it divides the selection browser to include levels but it’s not required if you don’t need it

 export: current view: YES – this is why we made the “Navis” view – there is another reason to name it “Navis” but that is for another day

export room geometry: do you really need the room to be a transparent object in Navisworks getting in the way of EVERY attempt to select something? consider not checking this.

try to find missing materials: if they are missing here they are gonna be missing everywhere, who cares?  if you couldn’t be bothered to find them and set up your Revit with them then they are obviously not important enough to be brought into Navisworks.  besides we can add materials in NW and then render but again that’s for another day.

2d Quantity Takeoff Navisworks

Navisworks 2015 now supports 2d takeoff’s from image files!

Sort of.  Wait, what?

While it would be great to import .JPG or better yet .PDF files right into Navisworks that is just not possible.  Hang on, I thought you just said 2D image files?  That’s right I did (because that’s what Autodesk said) BUT the only 2D file that is importable is the .DWFX format.  Ahhh – design review might not be dead after all!

Ok so I can get the designer to export their BIM file sheets to .DWF, no problem right.  Right, again sort of.  Just be careful importing the 2D sheets in from a .DWF as you will also get the 3D geometry, which is ok but I already have that from the .RVT file I appended so a quick hide will remove the excess 3D information.  (This annoyed me at first but after a little thought I realized that the exporting program might not be available and so having the 3D available in the .DWF is probably a good thing.)

Hang on, my designer only wants to give out .PDF files Sad smile

No worries they have probably made those .PDF’s using a proxy print driver from the cad application right?  Well we can simply re-print the .PDF through a proxy .DWF print driver that you can get here.

This is not limited to .PDF files, oh no!  Anything you can send to a printer an be sent to the .DWF printer instead, as a sample I give you a quick sample not of evolution but of BIMolution BIMolution

And as inserted in my Navisworks 2015:Screen Shot 05-10-14 at 10.39 PM

How Revit Network Version Works

There seems to be a misunderstanding of how Revit (well all Autodesk products for that matter) runs in a network environment but it’s really quite a simple process. 

Understand that CADD programs are too large and to processor intensive to run across your network as they would grind all network traffic to a halt, therefore CADD programs need to be installed on the users local computer & not on the server.  There is a very small program that sits on the server and sends a tiny file to each users computer to track license checkout status.  When determining the number of licensed seats a company needs to purchase the question is not how many users we have corporately but rather how many users need to be running the software concurrently.

This means that you may actually deploy 10 installations throughout your CADD department but only purchase 8 network licenses.  While all 10 machines are capable to run the software only 8 may be in use concurrently.

Know Your Navisworks Files

Many construction firms are now using Autodesk® Navisworks Manage as a tool for collision detection and coordination collaboration with other trades working on the same project. You could even say that it has become an industry standard, which is rare considering it is a software application (that has dominated the market, nonetheless). There is nothing comparable in its class. It flies through 40MB files with 10s of overloaded external references attached like it was a simple 24KB, one-line diagram in AutoCAD®. Okay, enough about my love for Navisworks. I simply wanted to get you in the mood for the following information on the subject matter.

To collaborate efficiently, the LBC (Lead BIM Coordinator) firm will bring all trades working on the project together for weekly coordination meetings, present the collisions with other trades, share potential problems with installation based on the 3D model they will be flying around in the meeting on a projector or smartboard. This is standard, and you won’t see much give or take in this particular situation. Some might hold biweekly coordination meetings while others meet weekly. Some save the collision viewpoints as screenshots in a physical paper collision log, to inform each trade of specific objects that need to be moved out of the way, while others might email the group, listing the collisions and the proposed changes and sign-off requests.

What will change drastically from firm to firm, though, is how the after effects of these meetings are posted to an FTP server, Autodesk Buzzsaw, or something similar. Three years ago, the NWD file format was the standard, and many people didn’t know of other formats that were being used to make things easier. Today, though, after we have been working in Navisworks Manage for countless coordination and collision detection meetings, we are finally at a point where even the project managers are educated on the different file types and the technological aspects of Navisworks, thanks to Navisworks Freedom, a free viewer that most upper management, GCs, and owners are using to fly through the model themselves via a ‘Read-Only’ type of navigation.

There are three main output file extensions from Navisworks. They are:

1. NWD

This is the main export extension for Navisworks models and is the most widely accepted. You can open an NWD in all Navisworks programs (Simulate, Manage, Review) as well as Freedom. This is the typical format to send to a large group of construction firms, as some of them are most likely using the free viewer or an early release.

An NWD file will consolidate all of the merged or appended models within that file, and bind them (for our AutoCAD users) into one large and in-charge file. All loaded models, the scene’s environment, viewpoints and the current view are all saved to the current file. This includes redlines, tags, and mark-ups. All NWD files are static—they will never change. They are not linked to any particular drawing or reference, and they are the slowest of the three file types to open. They are also the easiest.

2. NWC

These are Navisworks Cache Files. When you open or merge/append a Native AutoCAD .DWG or any other native model with Navisworks, if you pay attention you will see it automatically creates a cache file in the root folder that your native drawing is in, named the same except for an .nwc file extension. This is because it expects you to save this file off as a Navisworks model later on, and you most likely will.

Navisworks Cache Files are created mostly for ease of use and speed. When you open a model created in other programs, it creates a cache file that is much smaller in size, and you won’t even notice it. The next time that you open that same model, it will instantly load, rather than gathering the information for it. This is because it is now reading the information from the cache file rather than the model itself (so long as the original file isn’t newer than the cache file, in which case it will re-cache and replace the old one). It does this for each file Navisworks opens or merges natively. Another reason you may have heard of NWC Cache files is because that is what Navisworks Exporter uses as its main file format. If you have Navisworks 2012, you will notice that once you load Navisworks Exporters, your “NWDOUT” command no longer works in AutoCAD®.

They completely nixed this feature with the 2012 release and replaced this command with the much better “NWCOUT” command. It is much better, because you can instantly turn any AutoCAD (or similar) program file into a living cache file of itself to be merged into its master model. When the live model changes, so does your overall model. Navisworks Cache Files play a very important role in Navisworks’ new ‘real-time’ image. The only downfall is you cannot open Navisworks cache files in a previous release or Navisworks Freedom.

3. NWF

This is a Navisworks File Set. These are what you would typically want your master model saved as, linking all other models that pertain to your drawing. Your NWC Cache files are created for the NWF file extension.

With an NWF Master Model, you simply merge or append all of your NWC Cache files into the model, (or your native CAD files, which will be cached anyway). Your model then grows exponentially, only it does not contain any model geometry like an NWD, making it a much smaller file. Let’s say that you have four Navisworks Cache Files appended to your “Overall.NWF” model: “Mechanical.NWC”, “Electrical.NWC”, “Structural.NWC” and “Architectural.NWC”. You save all five (including the Overall.NWF model) in the same directory or folder, and the mechanical contractor decides that they need to move a VAV box 14’-6” west. They modify their drawing in DWG format, then save it. If you have the overall NWF file open, you can simply hit F5 (or the “refresh” button) and their changes will instantly appear, showing what collisions or installation problems that this recent change has created.

You can edit settings within your global options dialog within Navisworks Manage 2012. Future changes will be a different color making them easier to locate within your model. This is very useful when you are dealing with a massive, multi-tiered building that would likely have thousands of changes per week, especially in the beginning stages of collision detection.

A great tool recently released is Buzzsaw Sync. You can use Buzzsaw Sync in collaboration with the above named file sets to create the ultimate real time file collaboration. You can create a shared folder on your desktop, and sync it with Buzzsaw Sync. All of the other trade partners do the same, and you all essentially work to that same folder that contains the same file structure listed above. You can then have a living, breathing document formation that will show changes as they occur, rather than waiting another two weeks for that subcontractor to post their latest file to the server. You can constantly be a step ahead, working to, or behind, their latest model on an hourly basis.

A great way to post the Navisworks files from a coordination meeting’s flythrough is to first move all of the trades’ working drawings into a main Current Collaboration folder along with the NWF that is linking them all. Be sure to save viewpoints in the model, each looking at a collision or instance, labeled and numbered in the collision report to refer to and sign off in the next meeting. You can click on the viewpoint, make your changes, then on to the next. You should then save this weekly file as OVERALLMODEL20110904.NWD (dated) – 2010 version – and save it into the ‘current’ folder and then ultimately the ‘archive’ folder, so that everyone can see the current model no matter if they are using the free viewer or an older version.

You do not need to save the native working drawings into these folders, as the NWD is no longer linking them. Everything is bound within that NWD file.

You now essentially have two folders. One folder contains the overall NWF file with saved viewpoints, materials, scenes, lights, and markups along with all of the native working AutoCAD, Revit, Tesla..etc. files that it is linking (along with the .NWC Cache files that it automatically created for each). This NWF file will be automatically updated with each meeting, because as the native files update the NWF model updates with it. There is no need to save this overall file off as an archive because it would not contain anything. Instead, you would save the actual native working drawings off in a dated archive folder for safety and reference reasons.

The other folder will contain the consolidated NWD file, which has everything bound into it. Because this file is autonomous, you should save this file off as something like OVERALLMODEL20110908.NWD, and place it in the ‘Current’ folder. With every coordination meeting, you will replace this, and move the old one into the archive folder, preferably in a subfolder named ‘Navisworks Files’, while the trades’ native files will be in a subfolder named ‘Drawings’.

Of course, every company has its own way of doing things, and by no means is this the marked standard. It is simply an efficient guide to get you started off in the right direction. The above mentioned procedure works for any trade, whether you are an AE firm, a mechanical or electrical contractor, or a material handling company. If you use this procedure, you will soon see that it will make your meetings more proficient, and you will also learn that some specifics can be changed to fit your exact meeting type. Coordination has never looked so good!