The recent struggles with DG compound walls and floor junctions are more signs that BA is running out of headroom.
http://communities.bentley.com/products/building/building_analysis___design/f/5917/t/40550.aspx
http://communities.bentley.com/products/building/building_analysis___design/f/5917/t/42316.aspx
Bentley needs to look carefully at the current context that basic tools like BA’s wall tool needs operate in. There are many ways to look at this, but I would encourage Bentley to look at emphasizing the ‘horizontal’ dimension of the BIM world as described by Chuck Eastman at GA Tech.
BIM Confusion / Myths:
I think that most productivity gains attributed to BIM are really in what Eastman calls the vertical integration markets, not in horizontal integration. Best example of vertical integration is structural ‘hot rolled’ steel. Shared 3d models, analysis package integration and automated detailing, fabrication etc have delivered compressed programmes. Similar productivity gains will be more difficult to repeat in a lot of the other ‘trades’.
The problem is the lack of integration in the AEC market, which is normally ‘vertical’ in nature. It’s a no-brainer for big integrated industries like the petro-chemical sector to invest in defining data dictionaries / ontologies and capture domain know-how in CAD add-ons for automated re-use. They reap the benefits directly. AEC is more fragmented and there is little incentive for the big ‘social investments’ in standardisation, interoperability, and knowledge capture / automation. The last item is probably the biggest problem and has the most relevance for horizontal BIM.
Horizontal BIM:
Vertical BIM is about disambiguation and avoiding islands / silos of automation. Data re-use by avoiding re-entry, ensuring completeness, and constraining or informing the design by the manufacturing processes are commonly cited goals.
Horizontal BIM on the other hand is about using representation/heuristics for developing, testing, communicating and coordinating designs. To do this, it needs to be able to provide a scalable computational design platform that handles data centric, propagating models. The platform also needs to support KBE by small and medium sized enterprises that don’t have big coding resources. It’s curious that Hollywood CGI houses increasingly tend to have a ‘technical director’ to ‘creative’ ratio that is 1:1 or greater. I don’t think this will happen to the AEC sector anytime soon.
Progressive Representation:
Designs / Information models are developed incrementally, almost in layers. H-BIM must be able to allow the designer to start with reduced data (primarily geometric aka conceptual modeling?) and use the initial constructs to drive ever more detailed or foreign constructs downstream. Enabling paradigms should include associative / history-based parametrics (GC-ish?), rule based selection / processing (Design++, JSpace?), constraints based modelling etc (PowerCivil geometry platform?). While these techniques are not new, there does not appear to be an overarching framework that ties them together, thereby allowing design intent to be franchised / pervasive.
Working in this layered way also emphasizes the need for intelligent, features like persistent arrays / patterns, ACS’s, connectors, workplanes, axes, points that can be imbued with user-guided ‘semantic / ontological’ information. These key / orienting / structuring objects need to be able to propagate intelligently in a hierarchy or network structure.
Revit 2010 supports the nesting of reference points, axes, curves, planes, which allows the user to quickly build a ‘rig’ to drive a massing model. The massing model can then be cut up and ‘wallified’. This workflow reminds me that one area that ‘BIM’ has demonstrated ROI is automated area/volume calculations, which is important for the client signoff and cost control process. Massing, programme, room scheduling is often a 3d affair (See DProfiler + Affinity) where the overall envelope or cumulative scalar information like areas can drive walls / floors.
Compared to the 90’s, this is a far more complex context, where bi-directional associativity and design intent in the form of driving dimensions / constraints need to be dealt with. BA’s Space planner tool is based on the new EC frameworks. Perhaps walls should be rewritten as EC components? EC look more dynamic and could provide the common 'federating' ground to tie all the building / structural / civil etc verticals together.
Revit also has some basic functions to ‘glue’ walls to floors and vice versa. As discussed in one of the threads listed above, the functionality provided is minimal. But, why is this? Revit is supposed to be a ‘context driven parametric change engine’ that avoids large constraints sets and long regens that come with history based systems.
http://www.cadalyst.com/aec/1-2-3-revit-not-all-bim-parametric-2929
It has families of components, so it could use a rules based inference framework to propagate changes that maintain relationships between components. For example, if the user puts a kink in an external wall, a corresponding kink could be propagated to the floor slab. The problem is how to give the user control of this hidden ‘hardcoded’ behaviour. I can also see the propagation getting out of hand. How does the user restrict the kink to the ‘work’ floor only? Also, since there is no ‘history tree’ to prioritise things, and there can be concurrent edits merging / propagating thru the ‘central file’, so Revit will be forced into bigger and bigger combinatorical problems?
Digital Project takes a more transparent MCAD based approach: It makes use of support planes or surfaces offset /constrained from a system of grid lines. Propagation is history-based but is supplemented with constraints solving in discrete ‘sketches’. CATIA elements have rich ‘update’ methods that include ‘delimiters’ that look for suitable ‘cut-off’ elements. So, the slab can be constrained to stop say 250mm back from the building envelope plane/surface. Internal walls can be dimensionally constrained to other walls or grids.
GC is also a powerful history based tool, but it needs to be able to embed its intelligence in whatever it throws ‘over the wall’ to BA / Mstn. At the minimum, it needs to be able to include ‘ontological’ info like ‘I am a wall on the 7FL, south, ACS: A-7S etc’, so that when it is interacting outside GC, other intelligent objects like pipes can react to it. Speedikon has an intelligent ‘services penetration’ object that automatically recognises pipes that penetrate its walls. PDMS12 stores this kind of design intent as ‘attachment points’ that are associated with the interacting elements. So when a pipe is moved, the ‘attach point’s are queried for the relationships that need to be maintained so that the associated elements can be modified. I suppose PDMS already uses something like Design++ to capture domain production rules that would govern how the modifications will be made. Unlike Revit, these relationships would be exposed to the user as the attachment points are editable, I think.
The ‘ontological info’ should be detailed enough so that follow-on objects / tools like Sketchup’s ProfileBuilder can rebuild and react to changes in the reference geometry. So, the wall object should be able to store which edges are top / bottom, internal /external, core / cladding / cavity and other domain specific semantic clues.
But the clues will vary with the particular interfacing discipline / vertical. Nevertheless, H-BIM needs to provide the linking thread / common denominator, a mapping structure between datasets... your metaphor here... What is or should be the underlying unifying information? Smart geometry must be high on the list, as ambiguous as it is.
Specifically for walls, ArchiCAD 12’s CW tool is a good prototype to leapfrog, I think. Allplan 2009's facade tool has matched a lot of AC12CW’s functionality, but the way AC can separate out the schematic grid prefigures a layered, associative, rules based way of working that is promising.
Just played around a bit with the V8i release, and one thing that really seems to have improved is the stairs tool.
I wonder if this is a hard coded solution, or if it is based on something else?
Hey Robert - we are doing jobs complete to section in BA. It just needs help and some joining amonst us all. Too many little things need to be improved - centerlines for example are wonderful in making my sections look great however I still cannot make a workable centerline for shingles. and little things like flashing I do now many times in 3d but it is not panless especially when you have unusual NON BLOCK shapes liek gables and slopes.
I need a moulding tool , doors that I don't have to program, etc. Patterns for elevations - etc. a better part library that works with MAsterSpec therefore links to labeling sections.
I need better dialogs so I can create walls without going though part peice and 5 different levels , etc.
Ustn since 1988SS4 - i7-3.45Ghz-16 Gb-250/1Tb/1Tb-Win8.1-64bEric D. MilbergerArchitect + Master Planner + BIMSenior Master Planner NASA - Marshall Space Flight CenterThe Milberger Architectural Group, llc
Robert,
since Revit model with all the documents is in fact one file, there are options to "finish" plans/sections/... in old-fashioned 2D way. you can simply mask all the unwanted content created from 3D model and draw simple lines. you can even create or import detail and link it with the geometry created in the plan. and what is great, once you modify (move) such geometry, your linked 2D detail is moving as well ... in fact, there is no need to export drawings to DWG for construction design finishing, it has tools to do all in revit.
another nice feature is that you can specify how detailed your drawing should be (kinda view filters from Speedikon), say in scale 1-200 the walls can be filled and in 1-50 walls are hatched in acc. to their material.
on the other hand, there is BIG problem once you come to big model. since everything is in one file, there is lack of response of HW while you do modifications. right now, we are finishing a project of office buidling of approx. 17K sq.m. (8 floors), the filesize is about 80M and despite we run 64bit systems with 64 Revit and machines have 8GB RAM, the work is not smooth.
another problem is when more people work on same model, there are situation when you just could lose the work you made since last save.
p.
/pt
Maybe you are correct about PC Studio being a bit of a stop gap. I think the biggest problem, and this relates to BA in a more general context is that nothing is properly finished. Whether you think that a model that is completely or even partly tied together by control volumes or some kind of relationship management
We can easily do everything I want to do up to the start of the construction process, but beyond that things get much harder. These problems relate to detail, not to major control geometry. Whilst its a nice thing to be able to move the major geometry around very late in the process its very unusual for a client to ask this in my experience.
My frustrations are all in the detail of how building components come together which makes drawings look unfinished. Its been a long time coming, but I am on the verge of deciding for productivity reasons that stage F (producing construction information) we will drop back to 2D. On more ambitious projects we will switch to using a more heavy weight scripted approach, which I think is the route to solving the kind of problems that only Architects really understand well enough.
Having never used Revit or Archicad, but seen demos of both, do those applications not have the same issues? Issues of detail?
Robert
rklaschka: As I understand it DD Design (dimension driven design) is a 2D function, its also intended as a constraints resolver, which whilst I am not an expert on it is something a little different than a parametric cell builder. What I don't understand is that the general problems with PCS are in the interface based, and yet most of the dialogue here seems to focus elsewhere. If PCS: Integrated better with BA, both with access to parts/families and with better export straight into the dg system say. Resolved the display problems it has with some graphics cards Had a series of templates and clear, complete documentation for the common types (doors, windows etc.) Had complete documentation generally Would you all reconsider using it? For me if these issues could be addressed, which I accept is a big ask, then it would work very nicely. Robert Klaschka
As I understand it DD Design (dimension driven design) is a 2D function, its also intended as a constraints resolver, which whilst I am not an expert on it is something a little different than a parametric cell builder.
What I don't understand is that the general problems with PCS are in the interface based, and yet most of the dialogue here seems to focus elsewhere. If PCS:
Would you all reconsider using it? For me if these issues could be addressed, which I accept is a big ask, then it would work very nicely.
Robert Klaschka
It would seem to me that PCS is a tool that was a stopgap as no real development has happened to BA in a long time. (PS. 1 upgraded stair tool in the last 6 years is not development of BA in anyones books - OK a bit harsh due to the exception of DG Cats)
It would be a start Robert, but Bentley have to realise they need separate tools to acheive interaction between differnt objects. I think Curtainwalls and Ceilings in particular need separate tools that let you automate the setout of the object but then allow you to shift and change each individual element in its makeup but keep its relative linkages to the parts that make up the whole element. Curtainwall with a door in it. Curtain wall with a solid panel in it instead of glass to some panels. The abitlity to move a single mullion/transom in a curtainwall on the fly without having to "Drop" the object as a whole. To even have a spearate shape assignesd to diferent elements of a curtainwall. All these things lacking in BA.
At the monment we have to manually model each element as a spearate objects, so when the design changes basically you have to delete and remodl it all again. Something that other apllications/packages do automatically right from the start.