Clash Detection

Clash Detection

Modified 4/27/2016

This tutorial was produced by Kevin R. Miller and is copyrighted. Michael N. Smith, Todd Baxter and Mark Hunter contributed greatly to this tutorial.

Before going through the tutorial, you must have Navisworks Manage 2015 installed on your computer. It is also recommended that you have all the service packs installed as well.

This tutorial also assumes that you have downloaded the zipped data set and that you have extracted the Navis tutorial data set from the downloaded file.

Open the Clash Detection Models Aligned.nwf file (if you are not seeing the file, change the Files of Type to NWC) found in the dataset directory. For this tutorial, the models have been sectioned into just the subgrade and first floor models. This makes the data set smaller and more manageable. If all the floors were included, there could be so many clashes that the amount of data could become overwhelming.

Navigating Navisworks

A few tools that will help you navigate around the models are the following:

Select is a tool that can be used to select objects in the model. If you hold down the CTRL key several objects can be selected. The Select tool is found on the Home ribbon.

Select Box is a tool that allows several objects to be selected while dragging a box around the objects. The Select Box tool is found on the Home ribbon by pressing the down arrow under the Select tool.

Once an object or set of objects has been selected, the option becomes available allowing for turning off all the objects that are not currently selected.

Other useful navigation tools can be found on the Navigation bar. (It should be visible) If it is not visible, go to the View ribbon and select Navigation Bar . The tools below are found on the Navigation bar.

Orbit allows the view to be rotated by left clicking the mouse. Holding down the center roller button on the mouse allows up and down movement.

Zoom Box allows the view to be zoomed into the box created by left clicking and dragging.

Walk allows the view to walk to different areas of the model. Pressing the left mouse button and moving the mouse up allows the view to move forward. Moving the mouse left or right moves the view left or right.

Press the roller button and move the mouse either up or down moves the view up or down.

Rolling the roller button changes the angle of the view. People that I have talked with tell me that using the walk tool is the most common method used to move around the model.

Adjusting Palettes

If you want several palettes to join together, making them “tabbed”. Select a palette by the top bar and drag it on top of another palettes top bar and watch at the bottom of the palette for the outline of a tab and then release the mouse. This will make it so the palettes take up less space on the screen.

To separate them, grab the tab and drag it off the palette.

Options

To make Navisworks easier to use, some of the program default settings need to be changed. Make the following two changes:

Press the Application button , select Options, expand Interface and select Display Units. Change Linear Units to Feet and change Decimal Places to 2. Press OK.

Press the Application button , select Options, expand Interface and select Selection. Under Highlight, ensure that Enabled is checked, Method is Wireframe and change Color to Pink. (This makes what is selected standout). The reason pink was selected is because it is a color that is typically not assigned to one of the building systems and it stands out.

In the Options Editor window, expand Model, and select Performance. Under the On Load section, place a check mark in Close NWC/NWD files on load.

If you don’t want to see the green level line, on the View ribbon, unselect the Show Grids tool .

Search Sets

Search Sets make it so you can export the clash tests and use them on future projects. This reduces the setup time for projects that you will work with in the future. The Timeliner tutorial will also work with Search Sets. For this tutorial, you will import the Search Sets to adjust the appearance of the models and then create Search Sets to help with Clash tests. A Search Set was created to select each model contained in this NWF file. The models contained in this project include: Architectural, Concrete, Electrical, Mechanical, Plumbing, and Structural Steel.

To Import the search set, go to the Sets palette (Home ribbon, Sets, Manage Sets).

On the Sets palette , select Import/Export, Import Search Sets and browse to the Navis2013ClashDataSet folder and select ModelSearchSetsv2.xml. This Search Set helps in selecting each model to clash.

If a consistent file naming convention is used, as updated model files are loaded, the same Navisworks files can be used to verify that the clashes have been corrected.

Open the Find window and spend a minute and look how each of the Search Sets work. Generally, the Search Set is selecting the entire model by the file name and selecting it. The advantage of the Search Set is the ability to use

Appearance Profiler & Workspace

If you use the Appearance Profiler you can create color defaults for different types of systems based upon the Search Sets that were just imported. This profile then can be reused for each project allowing for standardized colors to be quickly applied to the project. The Appearance Profiler is found on the Home ribbon in the Tools area.

Adjust the settings in the Appearance Profiler to what is shown in the image to the right. To do this, select the Set, change the color and select the Add button. Do this for each Set. If the Sets are not visible, try pressing the Refresh button.

/ RED
White
Gray
Yellow
Light Blue Brown

Press the Save... button and name the file Appearance Profile Clash. These colors could now be loaded for future projects.

Now press the Run button to apply the setting to the project. Close the Appearance Profiler palette.

A second method of changing a color is to do the following. This method only makes the color change for this project and needs to be performed on every project where you want to change a color of a particular system.

Generally, it is a better practice to set the default colors that you want to use using the Appearance Profiler above. To change the colors, right click on the various models in the Selection Tree palette, select Override Item, Override Color.

Workspace

After using Navisworks a little bit, users tend to develop a layout of all the palettes that they like to use. To save the layout that you prefer, on the View ribbon select Save Workspace, and the palette that are open and their locations will saved.

The tabs highlighted above are the palettes that I use often. Using two monitors provides more space for all the data on the various palettes to be visible at once.

Clash Detection

Creating Search Set for clash detection

For this tutorial we are working under the assumption that a clash between a light and a diffuser can be ignored. To do this, we first need to create a Search Set for the Lighting Fixtures and then a Search Set for the Diffusers.

A Search Set searches the model(s) for an objects property that you specify. One method to do this is to walk around the model until you find the object that you want to find and then Select the object. For this tutorial it doesn't matter which light you select.

Now zoom in so you can easily select a light fixture, then select the light fixture.

Once the light is selected, on the Selection Tree palette, it displays a few of the properties of the selected object.

In the image above, it shows a tree structure of object properties for the selected light. Since we want to select all the Light Fixtures, notice three levels up from the object is a group containing objects named Lighting Fixtures.

This appears to be a grouping that should contain the light fixtures. Now I could either go and manually select each fixtures or I could use a search set that would select all the fixtures. Time wise, it is much quicker to use a search set.

To create Search Sets it is helpful to have three palettes open, Find Items, Selection Tree, and Sets.

If any of the above three palettes are not visible go to the View ribbon, and under the Window button, place a check mark next to the palette to make it visible. Then if the palette keeps docking to the side of the program, Pin it open.

On the Find Item palette, in the Category column select Item, in the Property column select Name, in the Condition column select Contains, in the Value column type Lighting Fixtures and then unselect Match Case. Press the Find All button and it should select all the light fixtures.

If you do not highlight any of the models on the left windows, the search sets will be more reusable for future projects.

Now on the Sets palette, Right Click and select Save Search. Name the Search Set Lighting Fixtures.

This process will be repeated below for the diffusers.

Try selecting a diffuser. Instead of selecting a diffuser, the ceiling is selected. Therefore, Hide the ceiling. With the ceiling selected, on the Home ribbon, select Hide tool .

With the ceiling hidden, a diffuser can be selected. Notice in the Selection Tree that there are, Return,Supply, and Exhaust(below) diffusers in the model.

With three different types of diffusers, three Search Sets could be made for each type of diffuser. Rather than do that, only create one Search Set that covers all three types of diffusers.

On the Find Items palette, make everything the same as the Lighting Fixtures, except in the Value column type Diffuser (make sure that Match Case is not selected).

Press the Find All and then Right Click on the Sets palette and Save Search as Diffusers.

Don't forget to turn the Ceiling back on. To do this, go to the Selection tree palette, navigate down the SCIENCE Arch VOL1.nwc, Ceilings, Compound Ceilings, ACT-1tree structure until you find the greyed outCompoundCeilings, Right Click on ceiling and next to Hide you should see a check mark. Select Hide and it will remove the check mark, making the ceilings visible again.

Another way to do this would be to select Unhide all on the Home ribbon.

To make the screen less cluttered, unpin the Sets and Selection Tree palettes for the next section.

Making a Test

A Test is used to store setting for clash detection. By using a Test, settings are made that clash one system against another system, such as mechanical vs structural.

Select the Clash Detective tab at the left side of the program window. If it is not there, on the Home ribbon, select the Clash Detective tool . Press the thumb tack at the upper right corner of the Clash Detective tool to pin the window open.

Select the Clash Detective palette and then select the Add Test button.

In the Name field type Mech vs. Elect. Press Enter.

Rules

In the early stages of coordination, the clashes between diffusers and lights generally will not be a big concern. As the coordination effort progresses, the lights and diffuser issues will be addressed. Rules provide a way to ignore clashes that we don't want to examine. Another example of this might be clashes be floors/slabs and floor drains.

Select the Rules tab in the Clash Detective palette and press the New button. On the Rules Editor palette, select Specified Selection Sets. On the blue '<set>' text, click on the set and select the Lighting Fixture and Diffuser sets that you created. Press OK. Be sure to place a Check mark in the new Rule.

In further discussions with experts in the industry, they do not like using rules, they would rather see all the clashes. However, this has been covered in the tutorial to demonstrate how rules could be used.

Select

On the Select tab, do the following:

1.In Selection A of the window, select the Sets tab and select Mechanical. In Selection B of the window, select the Sets tab and select Electric. This selection tells Navisworks which files/models/Search Sets to clash.

Clash test include the following:

Surfaces - Default

Centerlines

Points

Self Intersecting is typically turned off unless you are concerned with a system clashing with itself. An example of a system clashing with itself would be a mechanical pipe clashing with a mechanical duct.

For this example, only check for Surfaces to clash.

In the Run Test box at the bottom of the window, make sure the Type: is Hard in the drop down box. For the tolerance0 is a typical setting.

Press the Run Test button.

Viewing Clashes

After the clash test has run, a list of clashes appear.

Highlight all the clashes and right click and select Group Select Clashes , Not the New Group tool. Name the group Initial List. Make sure all the clashes are now grouped under the Initial List group.

In the Display Setting flyout window on the middle right of the Clash Detective palette is the Isolation portion of the window, select Dim Other.

Also place a check mark in Highlight all Clashes.

Some users prefer to select Hide others rather than Dim Others. This is a personal preference, play around with both to determine which method you prefer. For the Hide Other option to be effective, the clashes must be in a folder and you highlight the folder to show all the clashes in the folder.

By diming the objects you understand the surroundings of the clash. This makes it easier to evaluate the clashes to determine if the clashes could be groupedtogether, identify important clashes, and recognize unimportant clashes. You may also want to play around with the isolation settings to see which one you prefer.

If the bottom portion of the window is not showing, make sure the Items arrow is pointing down.

Use the Walk tool and navigate so you can see most of the clashes.

After walking around the model, it appears that the Cable Tray causes the biggest clash with the mechanical system, followed by the Unistruct supports for the cable tray. The clashes between the diffusers and lights do not show because they were excluded from the test by the Rule that was created.

Now orient the model to the Top view on the view cube and make it so that project north is at the top of the screen. By doing this, everyone will understand the view they are looking at and not get turned around in the project.

The colors in the graphic below may be a different color. If everything is the same color it is because both Item 1 and Item 2 are selected in the Highlighting box. Unhighlight Item 1 and Item 2.

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Grouping Clashes

Focusing on the big clashes as groups instead of treating them as individual clashes makes coordination meetings more efficient. In this tutorial project, clashes such as the cable tray with the HVAC ductwork seems to be a big area of concern. Doing a quick count along the cable tray, there are approximately 90 clashes between the cable tray and the mechanical ducts. In working with the design team and the subcontractors, it would be better to view this as either 1 or 4 clashes along the cable tray area rather than 90 different clashes.

If you view it as 1 clash, the idea would be that potentially, you could make an overall adjustment to the cable tray and correct the problems. If you view it as 4 clash areas (as shown below), you would be working from the understanding that each area needs to be examined closer to determine the best solution for each area. This tutorial will proceed as if there are 4 clashes along the cable tray.

Check Highlight all clashes and Select Item 1 and Item 2.