Auditing a Navisworks model for very distant items

I'd like you all to try something, open a large Navisworks project you are working on, if you press 'Page Up' to zoom out to the entire model, and you can no longer see the model or it looks tiny then you should audit it for very distant items.

This is something we recommend you do as a simple check whenever creating an NWD, large or small, but there are symptoms of models which desperately need this, I've listed a few below: -

• When you render your model through Presenter, only the background shows, or you seem to get holes or triangles missing from a render
• When you navigate the model it looks like you have a section plane in front of you, as described here
• Jerky performance when navigating
• Model disappears when rotating around the model
• When you zoom out the model disappears
• Two faces seem to occupy the same space giving a jagged looking surface

When focused in on the model select an item (not the whole model) and save this as a Selection Set. You will use this in a minute to identify the location of the model in the view, or return to the model at any time.

Press Page Up to Zoom out to the extents of the model. If the model is not zoomed out then the distant objects may be behind the model, rotate the model 90° and press Page Up again to Zoom back out.

Go to the Item Tools toolbar

Select the Move tool, a gizmo should now appear where the model is in the viewpoint.

Use the Selection Box tool to select the areas away from the gizmo and the model, in the image below I made four selection boxes, in the third selection box I found a single item, with the move tool still selected the gizmo shows where this item is. When items are selected, either follow the steps below for each item, or add them to a new selection set(s) for further investigation.

Use Page Down to Zoom in to the selected items.

There is a quicker route to do this by using the selection box to select the main model then inverting the selection, however this may miss multiple instances of the same item and will not give you as much control when looking for the distant items.

Once you have identified any very distant items there are several possible routes to improve the model quality.

1. The easiest method is simply to Hide those items, once they are hidden then the bounding box of the model will be vastly reduced, improving the symptoms listed above, the items however will still be in the model.
2. If this is a whole CAD file in a distant location you may need to apply a transform to place it correctly in the model or change the origin or coordinates in the CAD file so it comes into the correct location.
3. Go back to the native CAD model, use the properties to identify the object
   1. If it is distant from the model or at the origin coordinates in the CAD package then it should be placed correctly or deleted dependent on your model and practices. Save the model and refresh the Navisworks scene.
   2. If it is correctly placed in the model then you need to look more closely into why this part of the model has been translated incorrectly, check the options for reading the file in or look at alternate routes to bring the model into Navisworks. If you cannot find an obvious problem, log a support case with the model data and details of the very distant item (either on the Navisworks Forums or through the Subscription Center), we may also be able to use this to improve Navisworks file handling.
4. Check if the object has any transformation overrides placing it in the wrong place with Right Click > Reset Item > Reset Transforms.

Please let us know if this helps you out by leaving a comment below.

Comments

[Lee Mullin]

Hi Brian,

We know there's a wide range of models used so there's no set distance recommended. This article explains a little more about how our clipping planes are calculated which may provide more help based on the size of models you have. http://beyonddesign.typepad.com/posts/2012/01/why-does-my-model-look-sectioned.html
Best Regards

Lee

[D]

Thanks Lee

Is there than a maximum "unit" distance from the origin to the geometry that Navisworks developers would recomend?

Thanks
Brian

[Lee Mullin]

Hi Brian,

This article is referring to the bounding box of all the geometry on the screen, as long as the GIS coordinates don't have associated geometry, then the bounding box will just be around the model.

If the bounding box is huge (10000km) then there may be problems with viewing the models, and potentially accuracy but this is something we would recommend against anyway, as there is no benefit of having an origin point in the Navisworks scene.

[D]

Is the above just applicable for geometry?
How goes Navisworks cope with GIS coordinates (up to 10,000km)
What if we want to work to GIS coordinates and have our clash results report in millimeters. Is that going to cause major problems as it does in many CAD applications?

Cheers
Brian