Conducting a Simple Clash Test in Navisworks: A Comprehensive Guide

Welcome back to the Navisworks video series. In this video, I'll be introducing you to Clash Detective. Clash Detective is a tool in Navisworks that allows you to check for interference between model objects in one model or across multiple models.

This is an introduction video, so we will not be conducting any clash tests during this session. Instead, I’ll walk you through the tool and the tool’s features. I have the HeatingPlant.nwd model open right now. If you'd like to open it as well and follow along, go to your Lesson 6 folder, select HeatingPlant.nwd, make sure the Files of Type is set to either All Files or Navisworks NWD, and then click Open. We’re not conducting any clashes in this video—this file just gives us a model to use as we explore the Clash Detective panel.

If you have Animator or Scripter open, go ahead and turn those off so you’ll have more space to work with. It’s also useful to auto-hide the other panels so there’s room for the large Clash Detective panel. It’s the biggest tool in the program. To activate it, go to the Home tab and click the Clash Detective button. You can then expand or resize the panel. The panel is divided into multiple tabs.

Each of these tabs allows you to create rules, boundaries, and properties; conduct clash tests; create clash batches; and so on. The tabs allow you to configure the tests for your project. You can expand or collapse your test area by clicking the up or down arrow, and create tests by selecting Add Test and using the panel below to define what you want to clash against what.

You can clash entire files against other entire files, the same file against itself, or specific layers or geometry. The combinations between the two selections are nearly infinite. If you have a three-dimensional model, you can clash surfaces. If you have a two- or three-dimensional wireframe model, you can clash wireframes against solid surfaces, other wireframes, or even point clouds.

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If you have a three-dimensional scan of your building, you can clash the point cloud against other point clouds, solid geometry, or lines. You can set the Clash Type to either Hard—which means an object intersects or touches another object—or you can set a Clearance, or check for duplicates between selections in Selection A and Selection B. You can also define a tolerance—for example, objects may intersect up to two feet and still be acceptable.

The results will appear in the Results tab. If we run a test, all of the clashes will appear here in numerical order, and we’ll have the ability to group and organize them. We can also adjust how the clashes are displayed—either using item colors or status colors. The status color corresponds to one of the columns in the test window.

We can also use Dim Other and Hide Other to better visualize clashes. If we select Dim Other, everything else turns gray and only the clashes are highlighted. If we use Hide Other, only the currently selected clashes remain visible.

We’ll look more at the Viewpoints tab once we’ve conducted a clash test. From there, we can also control how Timeliner simulations appear in conjunction with clash results. We haven’t covered Timeliner yet, so for now we’ll leave the Show Simulation option turned off when running tests.

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Clash Detective allows you to export reports in several formats, including HTML and XML. You can also export images for your reports, making it easy to share findings with other teams—even those not using Navisworks. You can send a report in NWD format that includes the three-dimensional model but not the Clash Detective tool, allowing others to view it for free using Navisworks Freedom.

We’ll cover all of these features in the upcoming videos, and I look forward to exploring them with you.

This is a powerful tool—and one of the biggest reasons people use Navisworks.