Archive for February, 2011

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SARUG Meeting – February 2011

February 15, 2011

Greetings All,
Our February meeting has been set for Tuesday the 22nd and will be at the Breckenridge Group. I’m looking for someone or company to host food and drinks for this meeting so if you are interested please let me know as soon as possible.  I suspect we may have 25 to 30 people at this meeting.

Dan Russell with Sundt out of their Phoenix office will be presenting on the following:
 Agenda

  1. Introduction
  2. BIM Execution Plans
  3. Estimating
  4. Trade Coordination
  5. 4D Modeling (Project Schedules)
  6. Area Specific Detailed Modeling
  7. Modeling for Self Performed Work
  8. Case Studies
  9. Operations and Maintenance

This should be a very insightful meeting and a unique opportunity to ask those probing questions. 

On other business Steve, Jake and I are assisting the CALA Construction Documents class helping them with Revit and getting their heads around doing CD’s.  If you are interested in helping please contact Steve for more details.

Steve is also working with Justin Cross at CALA to conduct a series of Revit workshops, the first of which is this evening from 6:45 to 8:45 pm.  Again if you are interested in helping please feel free to attend. 

Until Then,
Carl

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Working with Formulas in Revit

February 6, 2011

There’s a nice synopsis on Revit formulas and syntax at:
http://revitfamilies.blogspot.com/2005/10/revit-formulae.html

Thanks to Mike Hardy Brown for the post.  Partially duplicated below incase we lose the link.

_______________________

TIP: Keep your units consistent. Do not mix units in your formulas. You can use constants with no units assigned to them.

Length = Height + Width + sqrt(Height*Width)
Length = Wall 1 (11000mm)+ Wall 2 (15000mm)
Area = Length (500mm) * Width (300mm)
Volume = Length (500mm) * Width (300mm) * Height (800 mm)
Width = 100m * cos(angle)
x = 2*abs(a) + abs(b/2)

Create the family geometry.

Create and label dimensions to the geometry. See Labeling Dimensions. Do not select the Instance Parameter option. In the Family Editor, formulas are available for type parameters only.
Click Family Types from the Design Bar.
In the Formula column next to the appropriate parameter, type the formula for the parameter. Notice that the formula begins with an equal sign (=).

Formulas can comprise conditional statements. You enter conditional statements in the Formula box for a numerical parameter.

A conditional statement uses this structure:

IF (, , )

This means that values are entered for the parameter, depending on whether the condition is satisfied (true) or not satisfied (false). If the condition is true, return the true value. If the condition is false, return the false value.

Conditions can use numeric values, numeric parameter names, or Yes/No parameters. You can use the following comparisons in a condition: <, >, =. You can also use Boolean operators with a conditional statement: AND, OR, NOT. Currently, <= and >= are not implemented. To express such a comparison, you can use a logical NOT. For example, a<=b can be entered as NOT(a>b).

The following are some sample formulas that use conditional statements.

Simple IF: =IF (Length < 3000mm, 200mm, 300mm)

IF with logical AND: =IF ( AND (x = 1 , y = 2), 8 , 3 )

IF with logical OR: =IF ( OR ( A = 1 , B = 3 ) , 8 , 3 )

IF with Yes/No condition: =IF (Long, 50, 60) where Long is a Yes/No parameter defined as Long = Length > 40

Embedded IF statements: =IF ( Length < 35′ , 2′ 6″ , IF ( Length < 45′ , 3′ , IF ( Length < 55′ , 5′ , 8′ ) ) )

The following are valid formula abbreviations.

Addition— +
Subtraction— –
Multiplication—*
Division—/
Exponentiation—^: x^y, x raised to the power of y
Logarithm—log
Square root—sqrt: sqrt(16)
Sine—sin
Cosine—cos
Tangent—tan
Arcsine—asin
Arccosine—acos
Arctangent—atan
e raised to an x power—exp
Absolute Value—abs

Driving Revit Functionality
Carl