by Garry Stockton
When running Navisworks, do you get lots of drop out? Does the screen refresh take forever? Does it feel like you are using a CAD system from the late 80's, rather than the 2021 release of Navisworks?
Image courtesy of Kean Walmsley
There are three main areas where you can improve the graphics performance with your Navisworks.
1 - Graphics card
Is it up to spec? Navisworks requires a graphics card that supports OpenGL 4.0. If you do not have this then you should look at upgrading. The general rule is, you get what you pay for. The more money you spend the more easily the card should be able to handle 3D models.
Are the drivers up to date? It is good practice to reinstall drivers if there are any problems in this area, especially if this is a reasonably new CAD system. The computer may have out of date or corrupted drivers and installing the latest drivers can often resolve this problem. You should go to your card manufacturer's website to install the latest drivers. We recommend you stick to the latest stable release rather than beta's on production machines.
Advanced Settings vary from card to card and different manufacturers. Interactive Textures and Lighting can slow things down a lot, if you strip the settings back to basics then switch things on again one by one to identify which is killing your performance.
2 - 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 will 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 or Revit 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 cannot 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. prioritised 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.
Something else to consider, 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.
3 - Navisworks Settings
Most of the settings in Navisworks are set to a low level by default and then intended to be increased for improved performance. Here are the main ones which cause problems:
Hardware Acceleration (Options > Interface > Display) – Without this Navisworks isn't using your graphics card, the minimum specification asks that you have a card that supports OpenGL, assuming you do then there should be no reason to have this switched off unless troubleshooting.
Frames Per Second or FPS (Home tab > File Options > Speed) – This is set per file, the higher this is the smoother navigation should be, however if you are redrawing a complex file 25 times a second, your card may not get chance to catch up and draw everything, the default is 6.
Guaranteed Frame Rate (Options > Interface > Display) – This is set across all sessions; Navisworks will ask the graphics card to draw a minimum of the FPS set above. If one of your files has a high FPS saved in it, then you may notice lots of drop out, if this is on, check your FPS rate to see if it is unusually high. If the model is refreshing very slowly, you may want to switch this on and check the FPS rate too.
Fill In Detail (Options > Interface > Display) – This will ask the graphics card once the camera stops moving in navigation, to fill in all the parts of the model that could not be drawn whilst navigating.
Advanced Settings like Occlusion Culling and Interactive Transparency (Options > Interface > Display) and Interactive Lighting, Materials and Hardware Shading (Options > Tools > Presenter) can be switched off if you are getting slow or unexpected results.
Also, test your model on a colleague’s system if it is a similar machine, try it out on there and see if you have the same problems with the same models.
There may also be other hardware issues, like not enough RAM, or the graphics card overheating, something corrupt on the machine or there may be too many other applications running. If, after going through all this, you still get poor performance then you should get in touch with your IT people or Cadline Support at customer.services@cadline.co.uk.
See recommendations for running Navisworks successfully, copy and paste into your preferred search engine: