Tag Archives: 3d Model

Drawing Complicated Polygons

It often happens that you end up drawing a complicated polygon element with multiple different nodes independent or snapped to other elements. For example, you may be drawing a floor or ceiling plan with the slab tool, snapping to the face of framing. It usually happens that at least one node of the slab ends up snapped to an incorrect point of the wall.

In most cases, I just keep moving and come back and adjust that node after the geometry is fully placed. If it is one of the first nodes of the polygon, I have even just canceled the operation and started over.

But as is the case with ARCHICAD, there is always a better way!


To cancel the last placed node of any polygon element (Slab, Fill, Polyline, Line, Spline, Wall, Beam, Roof, Mesh, Shell and some Objects), you only need to hit the delete key once.


Typing the delete key can be repeated to cancel each previous nodes all the way back to the first placed node. Just keep in mind the minor efficiencies that need to be managed. If you end up undoing multiple nodes just to fix one node, it may be faster just to move on and adjust or hit esc and start over.

Smarter Modeling & Top Link Settings

In the wake of our office presentation on Solid Element Operations, I have been getting a lot of feed back, questions, comments and suggestions on use of SEO’s and methods of modeling without them.

I want to point out three scenarios that I came across this morning. One is SEO’s done correctly, the other are wrong. These deal specifically with walls, columns and beams and their relationship to the roof elements above.

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Wall perpendicular to roof slope trimmed to roofs with upward extrusion

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Wall parallel to roof slope, extended to ridge height and trimmed with upward extrusion

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Columns extended beyond roof plane and trimmed with upward extrusion

The basic idea here is that elements are all extended beyond the roof and then cleaned up by using SEO’s. This is wrong for several reasons:

  • First, this habit will cause more unnecessary SEO’s in the project. And we have already covered why that is problematic
  • Second, these elements can interact, intersect, create voids in elements above, such as dormer walls
  • Third, these walls do not clean up correctly with their roofs in section, wall section, details
  • Fourth, it runs a risk of saving out incorrect or inaccurate IFC or SKP files

The correct method for making these walls/columns/beams flexible to design adjustments is to set them to the correct height relative to the story above. Top link the wall, even if it is grossly below the story above, as in this case where the floor to roof height is 18′ in the story settings; so the top of wall is -9′ to story above.

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18′ floor to floor height for floor/roof stories

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Wall Top linked to Roof and set at -9′

Future Proof Your BIM Process

The WWA BIM Manual home page describes Why, What and When we model design elements in BIM in a somewhat vague and conceptual way. Understanding this concept is incredibly critical though, since designs change throughout the various phases of the process.

We can not get away with not showing elements simply because we don’t know exactly what they are. A BIM process is centered around exploring what elements are and developing them in a circular process. We can take a basic idea or concept and explore massing to detailed iterations in a very fluid way; and if done correctly, we can either start over or go to final documentation with little or no time loss.

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The perfect example of this work flow and level of detail is cabinetry. Cabinet and built-in elements are not only dependent on the phase, but also the design for the best way to model them and when to add the details.

A flush panel euro style cabinet may be best modeled using morphs from the onset. A more shaker style cabinet with overlay panels may be best suited for cabinet objects with preset doors or custom door components. An inset frameless cabinet with recessed panels may be best modeled with walls and doors.

cabinet process

designing from Custom Profile to Morph to Object(s) ensures a seamless workflow and options to “back-track” without starting over

The important thing to note is that the IDEA portion (LOD 100: Basic shape/size), should always be modeled as basically as possible. This ensures that we do not need to know what style or type the element is at first to at least represent that the idea exists. The process to final documentation should be as gradual as possible, even if we need to show higher level of detail than the current phase warrants.

In the style/process example illustrated above, a cabinet type and door style could easily be transitioned to any other design, with little extra time spent on redoing model elements.

This is also one reason that objects (GDL based elements) offer more flexibility than massing or modeling with individual elements, such as morphs, slabs, walls, beams, columns. With GDL doors or cabinets for example, the door style can be changed globally by simply overwriting or replacing the door panel on all cabinets.

To change a door panel or cabinet type on a single morph element or collection of slabs, beams and columns, significant time needs to be invested into revisiting each cabinet elevation and making individual changes to each.

Multiple BIMx Files

Today we presented two design options for a project via BIMx. In the past I would have waited for option two to load (an awkward 60 second pause), or created some clever layer option in a single BIMx file.

In my pre-meeting setup, I ran a quick test to open a second BIMx in a separate instance of the application. To do this, drag the BIMx application to your dock for each instance of ARCHICAD installed on your machine (17, 18, 19). Do not use BIMx for AC16! It is slow and glitchy or non-operational on our operating system.

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To find each BIMx application go to you mac > Applications > Graphisoft > ArchiCAD V# > Add-Ons > BIMx, and drag each individual BIMx to your dock.

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Next open each BIMx from the short cut, go to File > Open… You will then be able to open up to 3 separate instances or versions of BIMx files. In my tests, I can open a BIMx file created from AC19 in any of these versions. I have not tested this in reverse, opening a 17 or 18 file in 19; but I assume if a 19 file opens on an older version of the software it should work in reverse.

One final note, tabbing between instances of BIMx is as simple as using Com + Tab; so navigation and presentation goes seamlessly from one design option to the next. If you need more than 3 instances or versions, you will need to resort to the awkward loading/pause.

BIM Element Wants and Needs

In recent project audits and reviews I noticed a few projects that had disconnected and un-parametric elements and objects to represent very simple model elements. A toilet, for example, with a separate drafted floor plan and 3d/elevation view.

It was explained that this was done to show the manufacturers specific dimensions, shape and style in plan. Although there are ways change or override an objects plan symbol to show exactly what is perceived as necessary, this raises a much bigger question. What really is necessary in a drawing/model element? We may want a plan symbol or elevation of an element to match identically to a manufacturers drawing, but is that really necessary? I would say an exact graphic representation to a manufacturers spec is very low on the priority list for a BIM element, at least in most cases.

The Needs

So what are the priorities for a BIM element? We can assign a hierarchy of what a BIM element should represent to better understand.

  1. A BIM element needs to be parametric with a single element representing all views. Without this criteria being met before all else, the drawings are prone to redundancies and inconsistencies, and we loose almost all efficiencies of a BIM model and BIM process.
  2. A BIM element should match the overall size of the manufacturers specifications. This ensures that critical clearances and space requirements of a specific model element are met. This is overall dimensions; because a basic 3D cube with an associated plan symbol may meet criteria #1 and would be far superior to disconnected 2d plan and elevation views of an element.
  3. A BIM element should be placed in the correct location as its overall dimensions relate to the space it will be installed/built in. It should be in the correct location in plan, elevation and 3d views to show its relationship to all other model elements.

After these criteria are met, an element will be consistent in all views, it will be easily managed, maintained and edited, it will represent the correct size and represent the design intent. Anything else a model element requires is not a project need, but simply a “want” of the designer.

What does this all mean? Simply that in most cases we do not need a manufacturers specific element. Rather we need a generic element that represents the manufacturers size and the designed location of an element.

The toilet, as in the initial example, could be a basic out of the box ARCHICAD toilet that was set to the manufacturers size and placed correctly in plan. This would be enough to convey the design intent and document the building sufficiently.

The Wants

There may be some obvious additions to the hierarchy above, but rarely if ever should these take priority over the needs of a BIM element.

  1. Elements that are not part of the documentation, such as furniture or decoration used for visualization only may not require much thought towards what the plan or elevation views look like, but only need to show a quality 3d view. Elements that are placed only for BIMx or renderings would be a waste of time to build a correct plan symbol and parameters for listing into the element.
  2. Elements that require a manufacturers specific appearance to properly leverage a models visualization to make selections. Appliances and plumbing fixtures may meet this exception, but these elements should also be modeled so that their plan symbol, elevation view and 3d representation may meet the BIM element criteria above.
  3. An element that needs a higher level of accuracy to show relationships to finishes may require additional criteria, but may not ignore the top 3 criteria listed above. For example, a wall mounted faucet may need to show relationship to grout joints. So an additional element criteria would be manufacturers detailed dimensions. For this type of element all other criteria must be met; which means a custom object would need to be built or downloaded to maintain the integrity of the model.

Moving Elements to a Different Home Story

You may notice that when you change an elements home story in the element selection settings, the elevation (height to project 0) also changes, or more accurately remains the same relative to its home story. This means that if you move a slab from the first floor to the second floor, it will move up the difference in the story settings.

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Home story changed from Story 2 to Story 3 (Please ignore the sloppy 3/64″ modeling)

Screen Shot 2015-08-26 at 1.50.47 PM Walls jump to story 3 with same relationship to home story

If, however, you need to locate an element to a new story, but maintain its relationship to project 0, so that it stays at the same elevation but is located on a new story, you will need to relink the elements home story. This is done with a simple right click function, rather than in the element settings. Simply select the elements  you want to change the story settings of, right click, select Relink Home Story… and the elements will remain at the correct height/elevation, but be set to the new home story.

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Right click after selecting the element to redefine the elements home story

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The elements will remain in their original location

3D View to 3D Document

The view map should include a source view associated with each 3d document. This is true for reflected ceiling plans, detail axons, whole building foundation diagrams or any other view where view and content will need to be maintained and updated. In this post I will explore creating a foundation axon document that can quickly be updated to add new foundation elements, both 3d & 2d, without losing previously documented content, alignment or view settings.

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The 3d view that a 3d document is created from should come from a camera or saved 3d window in the view map for consistent view angle creation. It should be saved to the view map with predefined view settings; if a layer combination doesn’t exist for the content you want to see, create one. The view settings should not be set to “custom” for any of the view map settings.

navigator- view map

Additional view content restrictions may be applied, but difficult to replicate if the model or content change. Things like marquee restrictions, cutting planes or filter and cut elements in 3d can be difficult (but not impossible) to replicate when the 3d document needs to be rebuilt from a source view. To ensure these settings can be duplicated with updates to 3d model/document content, these settings need to be documented, such as hotspots and marque or cutting plane locations or screen shots.

filter-cut in 3d

One tool that can be invaluable (and is widely underused) for 3d document rebuilding is the selections palette. Once you have the content isolated in the 3d window, select it and save it to the selections palette with a name that relates to, or matches, the view map name for the 3d window or 3d document.


Using this palette you can open the camera view, re-select the original elements, add any new elements to the selection and isolate in the 3d window. The selection palette should be updated for future use with this new selection.

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Now just redefine the 3d document (in the project map > 3d document settings) with current window settings and your document will match the original camera angle, cone, and drafted content alignment; but will include the new model elements.

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