Revit 2015

What’s new?

Not much.

Commentary

I give up.

Revit 2015

Manufacturer Content - Lighting

I originally wrote the following on the HOK BIM Solutions blog and have since received some additional comments/observations that I would like to add here before re-posting (thanks a lot to Dan Stine!):

1. Revit does not support absolute photometry (i.e. LED IES files). This probably has to do with the format of the IES file where there is a -1 in place of the wattage value for an LED file and Revit is not currently able to handle this, which means you cannot produce renderings for LED Photometry.
2. An IES file describes how light is emitted from a fixture and takes into account all geometry, color, reflectivity and all other characteristics of the fixture. The reflector is only required to be modeled if you’re using a light source to make the fixture look more believable, or through using a self-illuminating material on the lens (the post below will describe all this in detail). These are also invaluable for lighting calculations, not just renderings.
3. Once an IES file is used, the family remembers the information and a link to an external file is not necessary. This is similar to the behavior of MEP families in 2014 which contain embedded lookup tables (note that even though it appears that the Photometric Web File parameter can be connected to a custom text parameter, it does not seem to work. A support request was filed to confirm if this is a bug).
4. Things get more complicated when doing lighting analysis such as with ElumTools, which require lighting content to be created with specific standards:
• Nested light sources must be shared
• Light source ignores all geometry in the host family
• Light from nested families “sees” geometry in host family (e.g. shadows from the arms of a chandelier)
5. Another challenge with rendering in Revit is reflectance. The Daylighting Analysis for Revit uses a formula based on the RGB values of the appearance asset for a given material. ElumTools uses a similar technique (which can be overridden in their Material Mapping dialog) but is based on the RGB value used in the Revit Material Dialog’s Graphics tab.

NOTE: This is a re-post from the HOK BIM Solutions blog

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:

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):

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:

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 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:

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 shadows, 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:

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.

Just 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?

Manufacturer Content - Lighting

Creating Non-Hosted Families from Hosted Versions

I just recently discovered this gem and it seems there are a few people that know about it. Perhaps it was discussed in a forum or some other place, but since I never came across this nice little tip, I thought of sharing it here.

In this post, I talked about a “pseudo face-based family” and this week while I was not even thinking about Revit or anything work-related for that matter, I just had a thought and wondered whether the hosting extrusion could be deleted (I know, my brain is weird sometimes!). So I tested this out and then realized that the resulting family is no “pseudo-anything”, but simply built into a host-less template with the Work Plane-Based option enabled.

So the highly-intuitive process (sarcasm anyone?) of taking a family that is built in a hosted template such as face-based, wall-based, ceiling-based, etc. and produce a non-hosted copy is as follows:

1. Place an instance of the family you want to hack in the drawing area. You can insert multiple ones at the same time;
2. Save the file and close it;
3. Open a new Revit file from no template. This ensures it is completely empty and Revit will thus create this hacked copy when we do step #6;
4. Link the previously saved model into this new file;
5. Go to the Collaborate Tab>Copy/Monitor>Select Link and pick the linked file. Once in C/M mode, click Coordination Settings and make sure that the family types you want to hack are set to “Copy Type”;
6. Click the Copy button and pick the families you want to hack;
7. Finish and exit from this mode when you’re done.

The copied families that Revit created are hacked versions and no longer built inside of hosted templates. Now simply edit the families, delete the extrusions, set them to not be work plane-based and save them…done!

Now I ask, if Revit is able to do all this, why not give us a stupid button instead of this frustratingly long and obtuse workaround?!

Creating Non-Hosted Families from Hosted Versions

Data Management

Data management is something we struggle with constantly, and the more we collaborate across the globe and beyond the walls that contain a single office, the more complex it becomes.

I don’t typically post advertisements here, so I’ll keep it short and add my commentary (what, you thought I wouldn’t have anything else to say?!). Imaginit have made a free video available about this topic, demonstrating how Autodesk Vault could address multiple workflows. The first 15.5 minutes of this video are dedicated to an AutoCad workflow, whereas the rest address a hybrid workflow which also includes Revit Server and their related product, Clarity.

 

To be honest, Vault has never really struck a chord with me because it was built primarily to manage a multitude of files that need to be accessed by one user at a time. This issue goes completely out the window with Revit projects, where the only useable component becomes linked file control. We can already do this in a multitude of ways (ex: Newforma InfoExchange transfers) and Vault just seems like too much complication for in-house collaboration. The only thing that could have some promise is family management and the ability to reference “published” files (as opposed to “live” files) between office locations. For example HOK offices collaborate a lot amongst each other and we utilize a series of techniques, depending on team setup. A simple method entails server to server nightly file copies to be used for linking purposes. This simply automates the transfer of linked files between offices, whereas with external consultants, teams initiate file transfers on a weekly basis via InfoExchange. Vault appears to have some potential to achieve this as well, but just seems like too much technology to manage. Why complicate when you have something that is quite simple and works already?

In the last few minutes of the video, we see a glimpse of Clarity. I think the software has a lot of potential and nice features, such as the Room Data Sheet reporting functionality which is all interlinked with other reports, but unfortunately I believe Imaginit has slammed the doors shut for most companies thanks to the (excessive) price point. I think the enhanced security features that can be added to a Revit Server infrastructure are quite powerful, such as limiting external team access to certain projects. However it is much, MUCH cheaper to simply install a couple of additional virtual servers to host a dedicated Revit Server infrastructure to handle confidential projects.

Imaginit also have a nice e-learning portal called ProductivityNOW. They make some resources available free of charge such as white papers, seminars, tips & tricks, etc., while others are restricted to paid members. So go ahead and check it out, you might find something useful there too!

Data Management

Disk Space (Length?)

So you probably came across these highly informative messages at some point:

What Revit is usually trying to say is that there isn’t enough disk space and it cannot sync with central. The above were displayed on the same project, whose units were set to Imperial, so I’m not sure why Revit had a metric fit there for a moment. It appears that disk space is perhaps being measured per length of track on the disk? Ah shucks, don’t try making sense of it, just know to look at how much hard drive space (or perhaps network disk space) you have next time your users get these gems!

Disk Space (Length?)