Understanding cut geometry in Revit - developing deliverables from your model

David Light, Revit Specialist for HOK London explains how to use different family categories so you can develop detailed deliverables from families placed within your project environment.

This question has come up a number of times recently, but understanding how Revit cuts geometry is particular important if you trying to generate deliverables off your model. Contrary to popular opinion, it is possible to do this.

In the example below, the requirement is to generate a number of different plans representing a reception desk. But the prerequisite is to show these at various level, ie. Top View, View below sign-in counter,  a view indicating how the millwork is developed.

You first just need to know what families are cuttable and which families are not, the Autodesk Revit help file actually explains this very well. Then you need to understand how to use plan regions to control the different plan depths you require.

Start by changing the family category to “generic model”. This ensures that the geometry is cuttable in plan as well as section.

Replicate the plan views as required, for each plan you are trying to develop.

Then pick one of the views, then go to view and “plan region” and sketch around an area where you need to see a different depth.

Select the plan region and adjust its Cut plane as required, in the case of below I have dropped this to 500mm.

The resulting geometry will now look like this.

If you need to provide different areas at different heights, pull back the plan region or sketch around what needs to be shown at a different height and alter the cut plan.

In the image below; the resulting views with different plan regions added to represent how the reception desk will need to be shown on the drawings.

PDF to DWG …..DWF to DWG… hack

It is a well known trick that you can export a PDF to DWG by using Adobe illustrator. This is achieved by opening the PDF and then choose export and export as a DWG, assuming the PDF contains vector linework.

However, can you do the same with a DWF file?

Technically yes, there are various tools and plugins which will allow you to convert a DWF to a DWG, but you will have limitation in the quality of the linework. However, you may have some success if  the DWF contains vector linework with one of the following:-

• You can open the DWF in Autodesk  Design Review, then PDF it using acrobat writer, then convert the PDF as highlighted in the technique above, using Adobe Illustrator.
• Alternatively, you could open the DWF in Design review, choose Copy to the clipboard, then in AutoCAD, choose Paste Special to copy the elements into AutoCAD.
• You will need to scale up the resulting DWG in both cases and the quality will be very low, but it should be enough to start a basic schematic plan from.

Copying & Pasting Objects between families and projects

Have you ever wanted to copy and paste objects between families and projects? Yongmoo Hur BIM manager for our Hong Kong explains more…..

Assume that you started working in a project and need to model roof/exterior skin on the walls below using ‘Conceptual Mass’.

You may want to bring the walls into the Conceptual Mass, but you cannot do it in current version of Revit. Basically Revit does not allow us to copy objects between projects and families with some exceptions with lines. Most importantly, you can NOT copy anything directly onto ‘conceptual mass family’. You will get error messages below.

True - You can’t copy between families and projects. But you CAN copy between families. We can use this.

1. Click ‘In-Place Mass’ to start ‘In-place Mass family’

2. Using ‘Reference or Model line’ + ‘Pick Lines’, Trace profiles.

3. Before you ‘Finish Mass’, Pick the lines and paste it onto ‘Conceptual mass’. Because you are inside of an in-place family, you will be able to copy lines to Conceptual family template.

Now you can model objects in the Conceptual Mass family!

You can also model a mass, and you will be able to copy and paste the mass within edit mode (again, BEFORE you ‘Finish Mass’)

For those who are more interested, below are further findings about behaviour on that subject

• You can NOT copy and paste walls directly into any family templates.
• Linking Revit will NOT work. The ‘Link Revit’ button becomes greyed out.
• You can NOT copy model lines to the ‘Conceptual mass family’ template.
• You CAN copy model lines to regular family templates. Trace profile using model lines and copy and paste onto family templates- generic model, for instance. And you CAN load this regular family into Conceptual Mass Family. It would be great if we can get rid of this extra step though.
• You CAN copy detail lines to Profile family templates. -- Trace profile using detail lines and copy and paste onto the ‘Profile family template’. But you can NOT load this into ‘Conceptual Mass’

Select Previous in Revit 2011

When you select objects, use

Ctrl – to add

Shift – to exclude

“Ctrl + Left Arrow key” is the shortcut for “select previous”

Control Temporary Dimensions

Yongmoo Hur, BIM manager in our Hong Kong office explains how to control the appearance of Temporary Dimensions. We all know that Temporary Dimensions appear when you select objects. I would like to cover little bit of this Temporary Dimensions.

This temporary dimension will not show up when the model becomes too complex to show all related dimensions. You can force to show this by clicking ‘Activate Dimensions’

If you click icon underneath, the dimensions will turn into permanent linear dimensions.

You can change how these temporary dimensions behave. You can set Temporary dimension to measure from centerlines to centerlines, faces to faces and etc. Manage tab > Additional Settings > Temporary Dimensions

You can also change the size of text. Often these temporary dimensions become illegible interfering with other objects, and you can make it bigger and more legible!

The R icon > Options >Graphic Tab > Temporary Dimension Text Appearance

You can select the blue square, drag and snap to new points.

Disallow wall joins

Brok Howard of our St Louis office, shows how to use the disallow wall join feature in Revit Architecture 2011.

Rehost geometry in a different plane

How do you rehost geometry to a plane in a different angle? William Lopez Campo from HOK London explains.

When trying to move geometry around (ie using a sketch from a reference plane to another) you can rehost between parallel surfaces.

The steps I followed in order to let the geometry “jump” from a plane to another non-parallel are:

The geometry is hosted on the Plane A.

Set Current a horizontal plane, and draw from any point a line perpendicular to Plane A and another from its endpoint perpendicular to plane B.

Draw a point hosted on the line perpendicular to Plane A. Select the geometry and select “Pick...” in the Host dropdown list. The plane defined by the point on the line is parallel to Plane A, so the geometry will “jump” to the plane.

Now set the original horizontal plane as current again, and rotate the line. Drag the rotation centre to the endpoint of the line and snap the rotation for the lines to overlap. There will be a warning message of overlapping lines, ignore it. Notice that the point and the geometry will rotate with the line.

Select the Geometry again, and repeat the Host Pick... procedure, now you should be able to pick Plane B

And job is done!

Autodesk Univeristy 2010

HOK will have a healthy presence at AU2010. Along with its numerous conference attendees, HOK will be sending five speakers!!

Don Rudder from the San Francisco office will be a sole lecturer for the CP333-1 customization and programming class entitled "Leveraging the Tail End of the BIM Lifecycle with APIs" where he will speak on facility management capabilities using Autodesk Revit and Autodesk Design Review pulled together into an ASP.NET web environment.

James Vandezande from our builingSMART group in the New York office will be primary speaker for two lectures and one "Unconference." David Light from the London office will be a guest speaking in the AB220-3P class on curtain walls while Lee Miller from the San Francisco office will be guest speaking in the AB427-4 class entitled "BIM and IPD for Project Leaders."

William Lopez-Campo out of our London office will present two Virtual classes each twice all done in Español!!

Moving the Sun to adjust shaded views

There may be times when you need to adjust the sun and shadows in your model. With the introduction of the sun path tool in Revit Architecture, this is a lot easier. Bruce Madsen from HOK S.F explains. 

In the 3D view of interest, click on the sun icon in the lower-left of the drawing space.

When the dialog box opens, select the top option.   This will show the sun as a yellow ball in the view.

Revit displays the sun and sun path.

Modify the date and time as needed to adjust the sun – just click on the text and change the numbers.

After changing the text, Revit changes the sun angle and you can verify if it gives a better contrast.