B3 - Group E - Hamad Al-Hajri

           AutoCAD and Revit are rendering programs used by many building design firms because they offer more that what can be done with pen and paper. Although AutoCAD has been around for a longer time and is more popular, Revit is gaining followers by offering a bit more. What's similar between the two programs is that both are able to render plans or models in 2D and 3D. The user can create floor plans, floor elevations, construction material, and incorporate the structural systems with the architectural designs to virtually analyze how every building component works with the other. The plans and 3D models created can be presented from every angle, which is helpful when creating many floor plans and elevations from the single model created. Although the programs' interfaces look quite different, and the ease of use varies from one to the other, both are generally easy to understand and navigate through. Finally, as complex as these programs can be, they remain easy to use. Both have many tutorials from books to websites to online videos which make it possible for even a novice to design to imagine and create impressive buildings. 

           The difference between AutoCAD and Revit is the way of modeling. With AutoCAD, the design process is similar to many other design programs, such as Solidworks, in which lines and angles and shapes are used to then present 3D models.
Revit on the other hand offers more. It immediately creates real life dimensions and offers many components that can be added with ease, such as doors, windows, columns, foundation, floor, ceiling, and roof. Also, components families can be added, such as HVAC, plumbing, structural, or any other system. All these can be incorporated into the building, and any change to one reflects on the rest and on the design. Finally, as the models are being designed, elevations and views are immediately generated. Levels heights can be easily adjusted from elevation view. From these reasons, Revit proves to be far more superior than AutoCAD.


References

1- http://blog.digitaltutors.com/autocad-revit-draw-line/
2- http://www.autodesk.com/products/revit-lt/compare-products

Comments :
Maria Ayon
Yasmina

B3 - (GROUP B) - Matthew Zabiega

                BIM software is almost essential to any design firm as it allows for easily visualization, editing, collaboration and planning of the project. REVIT is arguably at the forefront of the BIM software. “Revit has now and will become more deeply integrated with the core of planning, conceptual design, detailed design, fabrication, and operation of our built environment” [2].  However like all things, nothing is perfect and REVIT certainly is not perfect.  Probably one of the biggest problems REVIT faces, it probably its biggest key feature; it is so incredibly complex almost to the point that no one is an expert. A REVIT model can be designed with huge amounts of detail, features and families, but the problem is to teach a new employee or teach a student. The learning curve varies from person to person, it may take a few hours watching tutorials and taking it out for a test drive before you can start ‘designing’ something incredibly basic. Once you feel like you have the hang of it, you hit a wall and have to ask questions (if there is anyone to answer) or watch another tutorial/buy books.  This process is almost repeated infinitely.

                Another problem I personally experienced is also another big advantage of REVIT; multiple people working in the same model at the same time. A REVIT model, if located on a server, can be accessed by numerous amounts of people that can work on the project simultaneously. Every now and then (more now than then) you have to save and reload the project to make sure you are seeing the most up-to-date model. This can present a relative big problem is someone either: goes a long time without saving/reloading, or tries to edit the same structure/family someone else is trying to edit. For the first problem, the work that person has just done may be over-written and possibly lost if someone has edited the space around it. For the second problem, if you edit a something in the model that someone else has already edited, it could cause the model to glitch, blend the edits or even crash. This requires a lot of planning if multiple people are working in the model at the same time, one way around this is to divide the work up so that no two people are working on the same thing.

                Sometimes REVIT is stubborn, anyone who has used REVIT can more than likely agree. The task may be simple but REVIT will not allow you to create that pipe connection, or connect those walls. A funny personal example happened at my last co-op, I was given the job to update the edits in a REVIT model. One thing I had to do was replace a 60 degree pipe take-off with a 45 degree take-off and then reconnect the pipe. For whatever reason it was, REVIT would not allow it. Fast forward 2 hours later, with our departments 2 best REVIT designer and the actual head of the REVIT department (person who is really good at REVIT), crowded around my cubicle, trying to figure out why REVIT would not create that connection. No Clash-detection. Check. No interference. Check. No turned off layers clashing. Check. Elevation and view correct. Check. No one could figure out what the problem was. It was becoming more of a personal dilemma for the designers to figure out this ‘simple’ problem. They ended up finding similar objects around the model, copying and dragging them into the needed place.

                Something that seemed so simple just took four people three hours to accomplish. Sometimes REVIT does not budge and you have to improvise. The REVIT software is always being advanced, there is a huge difference between REVIT 2012 and REVIT 2016 and I am sure REVIT 2017 will be even more glorious than the previous.

Sources:

1: http://aecmag.com/technology-mainmenu-35/450-the-trouble-with-bim

2: http://www.seandburke.com/blog/2014/03/29/is-revit-dead/

Comments:
http://ae-510-ay15-16.blogspot.com/2016/01/b3-group-b-kai-waechter.html?showComment=1453823169626#c7696118922486202263
http://ae-510-ay15-16.blogspot.com/2016/01/b3-dianna-vogel-current-issues-with.html?showComment=1453823803472#c1641956809589075840

B2: Group A- Yuanjin LI

Overall introduction
This Chapter provides an overview of the BIM technology include the history of how the technology developed, what is the very basic technology of solid modeling and what is the difference between today’s BIM software.
The basic concept of modeling is to build up a 3D model by 2D shapes. Boundary Representation (B-reps) and Constructive Solid Geometry (CSG) are two techniques used in solid modeling. The difference between them is B-rep stored the result of the definition as a set of objectives while CGS stored an algebraic formula to define the shape. Today all the modeling tools are incorporate these two technologies to build up the 3D model.

BIM platforms
Scalability is the ability to handle large project scale which contains a high level of detail. It requires the platform can always response no matter how much 3D model the project includes. This ability is critical when the platform need to manage hierarchical parameters. Normally scalability is limited by the operating system. BIM element library has various objects that can be imported for use. These can be very convenient and helpful. Extensibility capabilities are assessed based on weather this platform has scripting languages for user who need specialized functions.

This chapter also listed some different BIM platforms to compare in three aspects, as a tool, as a platform and as an environment. I will mainly compare Revit and Bentley in this post. Revit Architecture is the best known and the current leader software in Architecture BIM modeling field. It is easy to use with many hints and menus are perfectly organized. The generation support makes the drawing easy to manage and edit. Revit has a very large set of object library which can directly import into the drawing. It also has the larges set of associated applications. But the weakness is obvious which is Revit is an in-memory system, it will slow down dramatically when the file exceeds 300MB.
Next software is Bentley Systems. It provides a wide range of products for Architecture, Construction and Engineering etc. As a BIM tool, Bentley has a standard set of parametric objects. It also support user to create their own parametric objects. As a platform, all actions of Bentley are written to a file immediately, which means it occupies lower computer memory. The strength of Bentley is it can deal with almost all aspects of the AEC industry and very complex models like with curved surfaces. While the weakness is it takes more time to navigate.



Reference
Eastman, C. M. (2011). BIM Handbook : A Guide to Building Information Modeling for Owners, Managers, Designers, Engineers and Contractors. Hoboken, NJ: Wiley.


Comments
http://ae-510-ay15-16.blogspot.com/2016/01/b2-group-c-faisal-alghati.html

http://ae-510-ay15-16.blogspot.com/2016/01/b2-bim-for-architects-and-engineers.html?showComment=1453232670954#c6876795361243284229

B2: Group B Farnelli

I am sure that we have all had experience with collaborative work on a project, and the complications which arise when cross-discipline work is required. BIM programs such as Revit have allowed companies to better coordinate their projects, but these programs still have quite a few limits. For example, often BIM models are used only for the coordination of geometry. Calculations are instead done in separate programs, with each division forming separate models in addition to the central model. Updates then often need to be done manually, which may lead to errors. An increases in beam size which is not notices in the structural department may not be immediately updated in the Revit model, for example, and this may lead to coordination problems when a mechanical engineer places a duct or piece of equipment where he or she believes there is space. While the capabilities of BIM to help coordinate projects are incredible, such problems do exist.
Chapter Two in Charles M Eastman's BIM Handbook covers interoperability, the ability of programs to work together. In the above example, the structural software was not able to update the BIM model itself, and users must check for changes and update models. This leads to the possibility of human error in translation. Eastman discusses the various methods for communicating between programs, including file types such as .dxf which can be read and produced from multiple programs, as I am sure at least a few of us have experienced. I personally have used this capability to form AutoCAD .dwg files from structural models in the past, but this is only a line model and does not directly transition into a BIM model.
The section which most held my interest in the chapter was the discussion beginning on page 114 about Industry Foundation Class (IFC). This representation of various parts in a BIM model is able to coordinate various properties and definitions of different parts of a model. For example, a wall is associated with various spaces it is adjacent to, as well as its materials, fire rating, purpose, etc. While each wall may have many properties, an engineer may be interested in only a few. The structural engineer may not care about the thermal transmittance, for example. The problem with interoperability is that programs used to perform analysis will also need to be selective about which properties to read. Geometry is likely important in all models, but many other properties should be left out of models which do not relate to them. Model View Definitions (MVD) are important as they determine what is exchanged and what is not. However, these are determined by trial and error and may not be standard. According to the handbook, there had been 23 efforts as of April 2010 to define MVDs, each for different purposes and programs. Other attempts to allow for interoperability include several XML transports such as OpenGIS and BCF (BIM Collaboration Format), as listed on page 133.
As the interoperability between programs increases, there may be a need to store further information in the BIM model. For example, perhaps it will be possible to notify the mechanical and structural team members if a beam and a duct are losing clearance space in the model before clash detection kicks in. However, as the amount of information being stored in the models increases there may be increased problems in the future with file compression and determining which specific programs need which specific attributes.

EDIT: Comments on Dianna Vogel's post and Bryan Cummings' post.

B2, Group B - Cummings

Interoperability can represent two things: the ability to exchange data between different applications, and the ability for multiple applications to contribute to a unified model.  The most common case of interoperability is from a comprehensive model to analysis software or a CAD drawing.  In this case, data exchange is one-way.  The analysis software can receive a model, but changes to the comprehensive model cannot be implemented via the software.  The second case might involve a structural engineer making changes to a structural model on their particular software, which would thereby change the architectural model on the architect’s software, for example.  In the early development of BIM software, it was quickly realized that a major problem is going to be uniform language from on platform to another.  Without it, data could either not be properly or not at all translated between applications, and errors would need to be manually fixed, minimizing the incentive of BIM.  

To solve this problem, internationally recognized standards are being developed for how the data in BIM models is to be structured.  Industrial Foundation Classes (IFC) is the most widely used convention, being internationally recognized and public.  This ensures interoperability between various competing platforms without requiring a monopoly.  Each model element (walls, floors, structure, electrical equipment, etc.) has embedded in it data specific to several domains (architecture, mechanical, structural, construction, etc.).  Depending on the domain in which the model is being worked in, such as a structural design software, changes can be made to the structure-specific properties of the element, and can be translated back into the comprehensive model.  The below image shows how data is stored in any given element, in this case a wall feature.

There is, still, quite an array of limitations on the issue of interoperability.  Current geometric capabilities meet almost all design and construction needs.  It can also exchange simple parametric relations between systems, such as walls and extruded shapes, but exchange of complex parametric rules and constraints cannot yet be fully translated.  This is simply because the development of parametric translators is still in its infancy.  Properties are stored in various elements in property sets (P-sets).  These define the performance and contextual properties via things such as weather and geologic data, and intrinsic properties including window glazing, R-values, mechanical properties, concrete reinforcing, etc.  However, tolerance and uncertainty is not covered in this data.  Also names of types of spaces are not yet standardized, which are needed for adhering to building codes and other types of analysis.  These limitations require special manual editing of properties.  Another limitation in the realm of metadata relates to manufacturing requirements.  The level of detail in shop drawings which require all the necessary information for concrete pours and steel fabrication are not yet all stored on comprehensive BIM models.  Specialized IFC software can be used to overcome this, such as Tekla Structures, which contain ever bolt, weld, plate, beam, etc., for steel structures.  

These limitations and why they exist are important to understand for both the program developers and those involved in all disciplines of building design and construction.  Most limitations exist simply because the technology is still in development, and the capabilities thus far reflect the industry’s priorities.  While many in the design and construction industry may not want to get involved in software development, the software architects are not knowledgeable enough in the industry to know what functionalities are needed.  With better understanding of the software among designers, construction managers, fabricators, etc., will yield a better product to all disciplines through more functional interoperability.  


Comments:

Comment to Dianna Vogel: I liked the angle you approached this from.  You performed a good analysis of the architecture of IFC schema structure.  As members of the building industry we traditionally have no reason to be aware of Bezier surfaces and NURBS, which I looked into a bit after and during this reading.  As BIM becomes more elementary in our field, as with all technology (smartphones, for example), we tend to not notice what goes on behind the scenes.  That’s probably okay for operating a smartphone, but when designing a system as complex as a building, whose operation is responsible for the safety of the public, we should have a good understanding of the mechanics of our tools and their limitations.

Comment to Yasmina Shields: Fascinating article you cited on the cost of omitting interoperability.  I can see how most of the savings would travel through the structure of project management directly to the owners, but the architect’s and contractor’s savings are not insignificant compared to the owners.  So on paper the owner has the largest incentive to drive innovation in interoperability, but I wonder how able they are to be impactful in that position?  The designers and contractors are who interoperability directly affects, thus know what is needed in its development.  Working in construction on my last CoOp, better interoperability from Tekla could have made a lot of our work unnecessary.  This seems to raise a separate issue: that most in our industry don’t know or some don’t care about software, and the odds are most software architects don’t particularly care for the building industry.  I think the biggest challenge to the further development of interoperability may be the collaboration of those two traditionally separate industries, and less who the burden of driving progress falls under.