Monday, 24 March 2014

Filled Regions and DWG Exports

This sounds like an odd paring for a blog post subject, but they are unpleasantly related.

When a view contains the following items and you export to a CAD format, you will likely experience loss of data:

  • Families with nested Generic Annotation such as Security Devices, Fire Alarm Devices, Electrical Fixtures, etc.
  • A large filled region covering a big portion of the view, usually to identify areas of work and areas outside of work.

This issue was filed with Autodesk Support and it has been known for at least 3 to 4 years. It seems that regeneration of the nested families fails, which results in the absence of these devices in the export. They are actually still in the view, but since in most cases there is no geometry visible in plan except the nested annotation itself, you end up with no object representation. The following are some workarounds, some more acceptable than others, depending on your situation:

  1. Delete/hide the filled regions before exporting;
  2. Change the filled regions to Solid Fill and everything will export as expected. You will then need to open each exported file and change the hatch to something other than solid within the CAD editing software;
  3. Do not use component families with nested annotation. This is obviously not an acceptable solution for MEP (#2 or #1 seem to be the only viable solutions), but might be acceptable for Interiors, where they can simply show these devices through the use of Generic Annotation families placed directly in the view. These can be scheduled within Note Blocks if required, however this workaround means you cannot make these objects visible in other views to properly coordinate your work, or see them in elevations, sections and 3D views.

There is no good workaround for this issue and the best is probably #2. Let’s hope the Factory can get this fixed sooner rather than later.

Monday, 17 March 2014

Manufacturer Content - Lighting

I will reluctantly kick off this post first with a little rant: is it too much to ask from a Lighting Manufacturer, that their BIM content render appropriately? I think not!

I am sure (hopeful, really) that there is good lighting content out there, but I’d like to take you through a specific journey that in my opinion, was unnecessarily painful and is probably quite representative of today’s common reality. So here we go…a user needed to do some “quick” renderings of an interior, utilizing a fixture by Focal Point called “Equation”. Based on the marketing brochure, this is what these should look like:Brochure

Here’s the resulting render using the Architectural family downloaded from the manufacturer’s website (for the purpose of this post, I kept the exposure settings constant so you can easily see the relative differences):

OOTB

It is clear that the family is built incorrectly. The overall geometry might be close enough (it wasn’t to my liking either, so what you’re seeing in this post is a rebuilt version, where I broke it down further so materials could be assigned to different parts of the family, including the internal reflector), but lighting is not emitting through the fixture. Editing the family revealed that the lighting definition was not set to Photometric Web. The MEP version of the family did have the lighting set to an IES definition, but who do we really expect to do an interior rendering? In my opinion, if you have photometric definitions for your fixtures, you should use those definitions exclusively, no exceptions.

After downloading and adding the IES definition to the Architectural family (which was ceiling-hosted…more on that later on), we end up with this:

With IES

This is clearly darker than the original version, so the luminance of the original family far exceeded reality. Now, I understand that we’re not designing a lighting strategy/layout based on a rendered image, but we do expect the result to be perceived as close to the built reality as possible. The IES definition gets us closer, however we still need to do something about the fixture itself. The quickest, most efficient technique is to use a self-illuminating material for the lens, which results in a decent render if the fixtures are far from the camera, but would not be suitable for close-ups due to their “flat” appearance. In the example below, the material’s Luminance setting was set to 300:

Self-Illuminating Material   IES

Self-illuminating materials add to the general brightness of the image beyond what you get out of the IES definition, but there’s really nothing we can do about that, except tweaking the resulting render exposure to get it close to how we perceive the scene should look like.

For a more realistic look, the fixture needs to be built differently. You need to rough-in the internal reflector, place a tubular light source to mimic the lamp as closely as possible, and then nest the family into another one so you can set the additional Photometric Web light source. Since the family I was editing was already hosted, I nested in an empty family into it instead:

Lamp in fixture  IES

The most noticeable and perplexing issue are the inconsistent artifacts around some of the fixtures. I was able to reduce them a bit by shortening the light source, but they would not go away completely (I think this is a bug, but have not yet confirmed…comments welcome!). The other issue are the harsh Lamp in fixture with no IESshadows, which are a result of the lens material being incorrect (used frosted glass) and can be easily tweaked as we’ll see shortly. With this method you add a significant amount of light to the scene, above and beyond the Photometric Web definition. The image on the left uses the tubular light source only with no Photometric Web. I noticed that I was using the original family’s metallic paint for the reflector and once replaced with a non-metallic white, the scene improved slightly:

Lamp in fixture  IES   non-metallic materials

Tweaking the lens material was necessary to get this scene closer to the lighting atmosphere resulting from these fixtures, although those pesky artifacts mean that post-processing cleanup is still required to get a presentation-worthy product.

Lamp in fixture  IES   proper lens material

Lens Material SettingsJust in case you’re curious about the lens material, here are the settings I used after some trial and error (click to enlarge).

What an adventure! I really don’t think it should be this painful to make a “quick” rendering using manufacturer-provided content, especially when dealing with lighting. We really need to be able to drop in such families, complete with appropriate material settings, and move on with our design work, rather than requiring a total rebuild, tweaking of their materials and several test renders.

Lighting Content Building Tips for Manufacturers

  1. Start with a non-hosted lighting family so you can use the light source that is built-into the family template to emit light from the fixture. This also gives you the flexibility to simply nest into any other hosted family template, rather than rebuilding each one from scratch and making change management difficult for you and your users!
  2. By doing #1, the end user can then decide whether using a self-illuminating material for the lens is a better solution and they can simply edit the family to remove the light source (emitting from the fixture) if that is the chosen path;
  3. Nesting into a hosted template means you can now also use the Photometric Web definition in addition to the other light source used to make the fixture appear to emit light. If an IES file is available, the fixture should not use anything other than these definitions. Also, make them downloadable together with the families, not separately! It is torture to figure out which IES file belongs to which fixture and which configuration. See #5 to manage these better;
  4. Include proper materials!
  5. Use Type Catalogs instead of making a plethora of individual families. It is more difficult for you, and for us, to manage them otherwise;
  6. Don’t miss building the reflector and the cavity within the fixture where the “emitting” light source will reside. If you only consider the exterior of the fixture, your end users will have to spend a lot of time re-building them in order to produce acceptable renderings. And once they find another manufacturer that does a good job with their content, guess what is bound to happen?

Wednesday, 12 March 2014

COBie Resources

The folks in the UK at Bond Bryan Architects have created a list of numerous resources available on COBie – Construction-Operations Building Information Exchange. What is COBie? Check here first, and then pay a visit to the Bond Bryan BIM site for more: bimblog.bondbryan.com/cobie/

Tuesday, 11 March 2014

RIBA and Malaysian Institute of Architects delegation visit HOK

On Friday 7th March, we were honoured to host a delegation from the Malaysian Institute of Architects and the RIBA. Our presentation on HOK's buildingSMART design approach was co-delivered by David King, Technical Principal, London and David Shepherd, buildingSMART Manager, London.

2014-03-07 11.51.44
Stefan Jacobek, Senior Architect and Quinton Pop, Project Architect for International School of Kuala Lumpur explained how BIM has facilitated HOK's design approach to projects in Malaysia, particularly ISKL. Rafael Marks, the Project Leader for ISKL also participated in the ensuing conversation.

Although the meeting was scheduled to last for an hour, the thought-provoking Q & A session continued for at least half an hour more into lunch.

2014-03-07 11.48.18
We are thankful for this opportunity to disseminate HOK’s considerable knowledge and experience in BIM and look forward to future engagements with representatives of these professional industry bodies, both national and international.