Designing in Revit Using Parametric Formulas. Tim Waldock. PTW Architects

Transcription

1 TM Designing in Revit Using Parametric Formulas Tim Waldock PTW Architects

2 Introduction This presentation will examine the use of complex formulas to drive parametric components for the purpose of exploring design in Revit. How far can we go? Parametric formulas in Revit families could be used to assist anything from sketch design, iterative facade design to more mundane detail design situations such as building regulation compliance.

3 Inspiration Channel 7, Australian Technology Park, Sydney by PTW Architects

4 Inspiration KfW Bankengruppe Tower, Frankfurt by Sauerbruch Hutton

5 Scope This presentation will cover the following topics: Limitations in formulas in Revit; Techniques for getting around those limitations; Error checking in formulas; Formulas in conventional Revit families; Formulas in Adaptive components; Examples in use; V2012 features: changes to adaptive components; family type parameters; rounding in formulas; unattached voids.

6 Complex Formulas - Limitations Limitations of parametric Formulas in Revit include: Can t input negative values for location/offset dimensions; Can t input an array value less than 2; Can t use formulas in a material parameter; Can t choose from a predefined list of options; Reporting parameters seldom work in formulas; Conditional statements do not work with text or material parameters.

7 Complex Formulas Tips & Tricks Solutions to Limitations of parametric formulas in Revit: Negative offsets using a reference plane/line List of options by multiple yes/no combinations List of options by numbers Material parameters by visibility and yes/no settings Material parameters by type Array of 0 or 1 by visibility Error Checking Allowable range (NB. Warn users) Prevent minus values; prevent values that make a line too short Tricks with formulas Embedded (Nested) If, Not, And, Or conditional statements Locking values Notes for users Converting units

8 Formulas Negative Offsets Solutions to Limitations of parametric formulas in Revit: Negative offsets using a non-reference reference plane/line Calculation for offset

9 Formulas Multiple Options Solutions to Limitations of parametric formulas in Revit: List of options by multiple yes/no combinations

10 Formulas Multiple Options Solutions to Limitations of parametric formulas in Revit: List of multiple options by number and visibility

11 Formulas Multiple Options Solutions to Limitations of parametric formulas in Revit: Material parameters by visibility and yes/no settings

12 Formulas Error Checking Instructions to users Preventing invalid numbers

13 Formulas Multiple Options By Type Solutions to Limitations of parametric formulas in Revit: Material parameters by type

14 Formulas Array of One A user may want only one instance in an array within a family. Revit arrays do not allow this, and the formula breaks if a value of 1 (or 0) is input: Single instance overlaid by array Visibility controls to choose between single or array

15 Nested Arrays Using all these techniques, we can create a complex repeating pattern of elements that has patterns within it. By nesting arrays inside each other you can get parts of a pattern to repeat, and you can slowly build up complexity. Nested arrays means nested groups....

16 Nested Component Arrays Nested arrays means nested groups? Nested components

17 Nested Component 2 way Arrays Nested, nested, nested, nested components

18 Nested Component 2 way Arrays Nested, nested, nested, nested components

19 Nested Component 2 way Arrays Regular patterns Irregular Patterns

20 Unattached Voids in Families Arrays can be made of solid objects or voids or both. New Revit v2012 feature: Unattached voids in families This allows arrays of void objects Can be used to cut mass objects, walls etc (but not casework). Cut with Voids When Loaded

21 Nested Arrays - Voids Nested arrays can be made of voids exactly as for the solid pattern.

22 Nested Void Arrays Tricks & Tips Visibility setting does not work with voids Phil Read s void depth parameter trick for on/off Hosting Void arrays on curved surfaces Voids as extrusions Voids as blends

23 Error Checking Formulas - Warnings Visibility switch for warning message

24 Space Planning By using techniques with arrays, nesting and error-checking it is possible to create components that can be used to help the design process while keeping track of specific design criteria. In the following example the component could represent corridor double-loaded with rooms these could represent hotel rooms or else health-care bedrooms; and there may be a maximum corridor length allowed.

25 Space Planning In a project, the component has grip handles to control its length. Formulas calculate how many rooms it can fit into the designated length It stops short with an actual length to match the number of rooms. Once it goes over a specified maximum length, the corridor changes colour (warning) using an if statement formula to change visibility or type.

26 Space Planning Parameters for standard room sizes Areas to be scheduled & rooms counted per run of corridor Room module nested components must be Shared components to schedule in project. instance parameters for linking when nested Only needs to be done at the first level of nesting

27 Space Planning Irregular Layouts Choice Parameters for each room Arrays not possible Maximum control

28 Space Planning Irregular Layouts Many parameters & formulas tedious to set up

29 Space Planning Alternating Arrays A / B / A / B pattern Easier to set up Good balance between flexibility and usability Two arrays fitting together (spacing = double room width) Use Error checking and Array of one Nesting of components

30 Space Planning Alternating Arrays Nesting of components one each side Visibility controls for each side

31 Space Planning Alternating Arrays Details can be added eg. Bathrooms (back to back) Schedules of rooms in project

32 Adaptive Components Adaptive components were introduced for patching up irregular edges of conceptual mass surface patterns In v2012 they can be used for anything in the project environment Opens up all sorts of new possibilities in Revit Limitations Workarounds for limitations Tips and Tricks with Adaptive Components Examples of use: Escape Paths Space Planning Reactor Patterns

33 Adaptive Components - Limitations Because adaptive components came from conceptual massing environment, they have inherited many limitations: Cannot use arrays Cannot place flip controls Cannot lock to orthogonal when placing adaptive components Two built in origin reference planes do not define origin Conflict with Adaptive point 1 Very hard to lock location of nested components in adaptive families Very hard to lock orientation of nested components in adaptive families (flex in the family gives different results to in project) Double-nesting in adaptive components nested component orientation and location becomes increasingly unpredictable Not possible to lock adaptive points to work plane (?)

34 Adaptive Components - Workarounds Arrays poor man s array Arrays - Nest normal components into adaptive components host to points; Nested components must be shared component with instance parameters to work properly in adaptive components Set up points/intersections to snap to when placing to control accuracy. To get around issues with the two built in reference planes always put Adaptive point 1on the intersection of the two origin reference planes, and point 2 along one of the planes. NB. All demos show the adaptive points being placed at random bad practise. To control orientation/location of nested components nested component location is relative to reference plane origin, not adaptive point 1 : Place adaptive point 1 on origin reference intersections; point 2 along X axis Place nested components on origin reference intersections; or: Place nested components on a reference line between adaptive points, and rotate after placing; lock component origin to adaptive point then it may maintain orientation between points;

35 Adaptive Components - Arrays Poor man s array place multiple elements; use visibility controls and counters to control numbers Or Nest non-adaptive components

36 Adaptive Components - Examples Escape Paths Place points; make adaptive Line between points 1 & 2 (3D snapping) Make subcategory Escape Path dashed red Set line to subcategory Place dimension between points 1 & 2 Make instance reporting parameter Repeat between all points Create parameter for total length Formula to add up total This will give plan distance Always Vertical

37 Adaptive Components - Examples Escape Paths 3D escape paths Number of segments Caveat

38 Adaptive Components - Nesting Component nesting Link length parameters Always vertical OFF

39 Adaptive Components - Nesting 3 Point Adaptive Component Double -nesting

40 Adaptive Components Reactor Pattern Reactor Pattern The book Elements of Parametric Design * describes a number of parametric design patterns (see credits at end). One of these is the Reactor pattern, which Makes an object respond to the proximity of another object. Zach Kron has applied this to Revit, using Reporting Parameters and Adaptive Components * Here we develop the concept

41 Adaptive Components Reactor Pattern Reactor Pattern Poor man s array Nested components Control Points

42 Adaptive Components Reactor Pattern Reactor component

43 Adaptive Components Coloured Fins This principle can be applied to a real life example coloured fins shown at the beginning

44 Adaptive Components Coloured Fins Distance settings to control change Or by formula: Proportional Sine wave

45 Adaptive Components Coloured Fins Or by formula: Proportional Sine wave

46 Adaptive Components Rounding Rounding Function: Round, Roundup, Roundown Balance out Sine wave

47 Credits and references Zach Kron - Buildz blog. Index of parametric design patterns Zach Kron in turn references the following work, which is not specific to Revit: In Robert Woodbury, Onur Yuce Gun, Brady Peters, and Roham Skeikholeslami s book Elements of Parametric Design, the authors explore what it means to work/design/model/transform in a medium that is about CHANGE. Their thesis is that parametric thinking is an old method of designing and that computers simply enable this methodology. In typical CAD packages it is easy to create lots of geometry, but it is very difficult to change geometry. It is this shifting and changing of data structures as a response to intentions and performance requirements that makes for great design tools, and is the backbone of parametric design. Phil Read: Into the Void AU2010

48 Next Time..... Organic Buildings.

49 TM Questions? Tim Waldock PTW Architects