Inside the Factory

Revit Sunrise: Draw Visible Elements Only - Occlusion Culling

I hope you have been able to give our Autodesk Revit Sunrise hosted preview a spin.  We’ve been reading your feedback - keep it coming. 

We posted a What’s new in Autodesk Revit Sunrise article, but you may be hoping for a little bit more detail into some of the features.   We’ll be trying to answer some of those questions and providing a bit more insight into the functionality in some up-coming posts.  To get things started, here is some additional detail about one of the performance improvements. 

The “Draw visible elements only” option improves view performance by occlusion culling. Elements that are obscured by other elements will not be drawn in the view.  This is done using your machines GPU.  In Revit, you will see the most benefit in 3D views with many obscured elements.  On average, we’ve seen a 30-40% improvement in performance during our testing, but your mileage may vary.    

There are a few things to be aware of with this feature as well.  Occlusion Culling is not used when shadows are enabled in a view.  This is so that things that might not be visible in the view can still cast shadows that would be visible.  Also, when selecting elements in the model, this feature will work the same with this turned on or off – even if the objects were not drawn because of this feature, they still can be selected as needed.  

You can enable or disable this feature in the Options dialog on the Graphics tab.  The setting is also stored in the Revit.ini file as “UseGpuOcclusionCulling”.   Because this feature uses your GPU, hardware acceleration must be enabled for this functionality to work and a graphics card that supports Shader Model 5 or higher is required.  This is a change for our system requirements (where the minimum is listed as Shader Model 3).  If your card doesn’t support Shader Model 5, the “Draw Visible elements only” check box will be disabled.   

Another interesting fact is that we developed this feature in partnership with AMD.

-The Factory

 

Revit Graphics Certification

With advanced graphics available within Revit, the development team is often asked how Revit graphics hardware certification works, and how graphics card manufacturers participate.

Any candidate graphics cards have to meet the minimum requirements of supporting DirectX 11 and Shader Model 3. Any graphics card that does not meet these requirements will not properly display Revit graphics.

For example, some lines (particularly hidden lines) will be missing from models, reducing the reliability of derived drawings created on that computer. If the target computer has a graphics card that does not meet these requirements we recommend turning off hardware acceleration (HA). When HA is disabled, Revit uses Microsoft’s graphics emulation (WARP) instead of the graphics card to produce accurate graphics, at the cost of performance reduction.

Even if a graphics card supports the above requirements, sometimes graphics drivers have bugs that result in incomplete compliance, causing incorrect graphics to be displayed in Revit. If you are experiencing problems with the display of Revit models we suggest trying a more recent graphics driver as the issue may have already been fixed by the manufacturer. Over the years we have identified a number of issues that have been reported by our customers and we have included them in a test suite that can be used to verify the functionality of a graphics card driver.

To test different graphics cards and drivers, the Revit team creates an application containing the test suite and makes the application available to graphics hardware manufacturers like NVIDIA, AMD, and Intel. The manufacturers can then run this application on their graphics card and driver combinations to generate test results. If the results show any issues, the manufacturer can make immediate changes to the drivers and test and repeat until no issues remain.

Once the test results of a card and driver are acceptable, the results are sent back to the Revit team for validation. If we find no anomalies the results are posted to the Autodesk Certified Hardware site.

A Case for Software Updates

When faced with the "Restart your computer to finish installing important updates" Windows pop-up, I think it's universal to click on the Postpone button. "I'll get to it later," you think to yourself, but sooner or later it's been days and that pesky reminder is still haunting you. Most of us do it; I'll personally admit to having gone weeks before finally taking 5 minutes to reboot. 5 minutes that would have saved me quite a bit of frustration and let Mike, our IT guy, sleep easier at night.

In an effort to change my habits (and possibly yours too), I'm going to tell you two Revit stories that show why regular software updates are so important and the good stuff you get when you take the time to update your software.

 

Story #1 - A Case of Better Performance

The Revit team runs thousands of nightly performance checks. Every day we have an accurate measure of how Revit is performing compared to the day before and compared to previous releases. Our goal - make Revit faster every day.

So imagine our extreme disappointment when one morning Revit view update is suddenly a whole bunch slower. The usual suspect: a component integration. Or is it? We can't reproduce the degradation on some computers. I'm thinking: now it's going to be difficult... Then someone suggests something - have we tried updating the graphics card driver? Somewhat to our surprise, it works! The updated component interacted badly with the outdated driver on the machines. By updating the driver, not only did we gain back all of the performance degradation from the component integration, but we crushed the Revit 2015 numbers. Here are the improvements we saw (thanks to Scott Blouin for the numbers):

Food for thought: Revit doesn't work in isolation - other software has bugs too. 30%+ faster performance may be just a driver upgrade away.

 

Story #2 - A Case for Greater Stability

Anthony explained MTBF (Mean Time Between Failure) in a previous post. I'd like to use some MTBF numbers as a data point to show why updating to the latest update release of Revit might keep you happier.

Update Releases (URs) contain critical bug fixes to the Revit software. This includes things like security patches, functionality fixes, and especially crash fixes. Each UR makes the software safer and more stable and the Revit team highly recommends installing the latest update. Each UR includes a list of fixed issues. If you're curious, here's the list for 2015 UR7. Code word for crash fix is "Improves stability."

When broken down for each update release, the Revit 2015 MBTF numbers below show a clear trend. Note: a couple of URs are not in this chart due to low adoption.

Revit 2015 UR3+ is approximately two times as stable as the originally released version of 2015. That means that users on UR3+ crash approximately half as often. That's a lot of work saved.

It's still early for UR5+, but we expect to see numbers that are consistently higher than UR3 as adoption grows.

Food for thought: Revit URs are designed to fix critical bugs and improve stability. MTBF is just one measure of how much impact they can have.

We'll keep making Revit faster and more stable, but in the meantime, happy updating!

Sasha Crotty

Putting Editing in Perspective

In Revit Sundial's What's New, you may have noticed this entry...

• Perspective views: Certain modeling capabilities are now available in perspective views: (See Work in a Perspective View.)
  • Editing tools: Move, Align, Pin, Unpin.
  • Reset Target tool: Restores the position of the camera target to the center of the field of view.
  • Toggle between the perspective and parallel representations of the 3D view.

Editing in perspective views has long been a customer request, so when I asked about it among the old-time Reviteers, most reactions were something like...

"Well, no one ever really tested it. We could try turning it on and see what breaks."

So, it turned out a number of things broke, which is maybe why we haven't just tossed it off sooner than this. A number of issues that turned up are fixable, but not immediately.

What Sundial has is what didn't break or was easily fixable. It could be possible to do more on this in the future. Interesting? Vital? Boring because you use 3DS Max for important visualization anyway?

Try it out and let us know!

Anthony

 

 

More fun with WebGL

I posted about a year ago about the rising trend in using WebGL to create hardware accelerated 3D graphics inside compliant browsers without the need for plugins. Well, this trend has really exploded. For some Friday fun I am posting some more examples of WebGL being used in innovative ways – but the keyword for 2012 is interactive. Developers are getting serious about making interactive 3D tools using this technology. Note: the latest version of Firefox 10 or Chrome is required. Sorry folks, no IE allowed here.

First up, Michael Dewberry, a Principal Software Engineer here at the Factory whipped up a WebGL exporter for Revit in just a couple of days. Unfortunately, this is not available publically (the devs here are using it to test new export APIs) but I got to play around with it, so I decided to export the geodesic dome I was working on last month.

3v version.  2v version. and the RVT file if you are interested.

Last year I played around a bit with WebGL myself and created this little “modeler.” It does not do much, but I was teaching myself Javascript and I wanted to see if I could create something semi-interactive.

 

123D Make, from our colleagues over in SF, is really fun. You can import a model and it will cut up the models into slices and lay them out on a template for cutting with a laser (through a service bureau) or by yourself (carpal tunnel alert!) Login required – but you can use your Autodesk services login. Worked better in Chrome for me.

 

TinkerCAD has come a really long way since I looked at it last year. Check out the breadth of projects people are creating with this fairly robust modeler. I also love the idea of “challenges” to help you learn. Login required.

 

I wrote about 3DTin last year. It also has come a long way from offering just blocks (ala Minecraft) to a new slate of really nice primitives.

 

Of these last three, Sunglass.IO has the slickest user experience. You can drag and drop your own models right onto the browser to load them. There is also a real-time collaboration aspect (which I have not yet tested.) However, I could not find out how to create new geometry. It seems like it is more like Design Review with real-time collaboration at this point.

 

I just ran across Shapesmith.net the other day (login required). Unlike 3DTin and TinkerCAD, it does not have direct manipulation of objects. But it DOES have some limited parametric control. Combine the two and you will really have something…

 

Real-time Rendering

Way back in the day, while I was finishing up my undergrad in architecture, I obtained an "unofficial" minor in Quake 2. After many hours of running through dark abadonded bases shooting at my studio mates, I began thinking: what if we put away the guns and used this to visualize our designs? I was told to shut up and guard the extra rocket ammo. Afew of us began experiementing. The tools at the time were very rudimentary - to say the least. Fast forward to 2003 and myself and some of my former battle buddies even started toying with the idea of creating a company to create architectural walkthroughs using Epic's Unreal engine. The graphics kept getting better and the tools easier to use, but licening the engine for commercial use made it prohibitive. We probably would have spent all of our time playing instead of working anyway. Fast forward again to today and we have a proliferation of great tools to create near-real quality renderings that you can actually walk through. I ran across Twinmotion over the weekend and was impressed by their videos. I have not yet had a chance to try it out, though.

Check out their aptly named blog, The Rendering Killer for more (Frame's modern house lives on!)

Jon Brouchoud at the Arch Virtual blog recently posted this beautiful walk through of the new Rutgers Business School building by Ten Arquitectos using the Unity game engine (see video below.) He also has some good tutorials and a downloadable kit for learning how to create these kind of walkthroughs with Unity and Revit. I have personally been working a lot with Unity and I find the engine to have the right balance of power, usability and cost (can't beat free! well, they upsell you for advanced tools, but still!) One of the paid features is the ability to publish your game (or walkthrough) to iOS or Android. Unfortunately, you have to navigate Apple's annoying provisioining labyrinth if you want to actually view it on iOS. But, if you or your intended audience have an Android device you can easily publish and freely distribute your walkthrough.

While not real-time quality, Brouchoud also has many great examples of using Second Life (yeah, remember SL?) to do design reviews. I like this very real example of seniors reviewing design options for their community space. Let just hope they don't wander out too far into SL, they may be shocked by what they find.

I am dissapointed to find VERY few examples from AEC customers using our very own Showcase offering for real-time rendering - from Revit sources or otherwise. Its not that the product is incapable. Far from it, if you check out their community, you will see some astounding examples from the engineering and industrial design space. To all you BIM-heads out there - is real-time rendering part of your arsenal for impressing clients and performing design reviews? If so, what tools and techniques are you using?

 

_tom

2012 Little Things: Type Selector

Now that 2012 is out of the bag I can take time to cover some of the smaller interface and design changes that made it into the product and might otherwise be overlooked. Today I'll review the type selector.

TS in Ribbon

When the type selector moved to the modeless properties palette some expressed a desire to get it back in the ribbon.  More choices for you.

 

TS Graphics

A small change in type names now align under the family name in the type selector drop down.  Previously type names were justified under the center of the image which created issues when trying to quickly scan the list.  This is very subtle but was easy so we knocked it off in the spirit of any positive change is good no matter how small and we should take opportunities when they present themselves.

TS in Sketch Mode

Saving best for last the type selector is now enabled inside sketch mode.  This was a very old behavior fixed.  I'll spare anyone the technical reasons why the button in the property dialog was disabled in 2011 but it was the same in pre 2011 releases though we did have a special property button that would bring up the type dialog then.  Now in 2012 the normal type button is enabled.  Kudos to the UI team for coming back to remove this inconsistent behavior that I know was source of annoyance. -erik

3D on the Web: Look Ma, no plugins!

I have been interested (obsessed, actually) with the idea of navigating and interacting with 3D worlds on the Web since the early days of VRML. Navigating and interacting with 3D on the internet has a long, torturous history. The solutions have fallen basically into two camps, both with their strong points and downsides. First, desktop gaming (such as Half Life, World of Warcraft, etc.) and virtual worlds (such as Secondlife) have been hugely successful at connecting users into a massive consensual hallucination. The downside of course, is that the entry points are still closed systems such as Windows, Mac and/or game consoles. The second, and less successful camp, is browser-based 3D. Almost as soon as the Web came into being, 3D was touted as the "next big thing." VRML, Java, and eventually Flash have all been used in a multitude of combinations to deliver interactive 3D to users on the web. Although these worlds were in-browser, they were (for the most part) solitary experiences and also required an additional plug-in.

I am happy to say that with the launch of Firefox 4 last month all of that is posed to change. Firefox 4, as well as the betas of Chromium and Webkit (Safari) based browsers now support WebGL. WebGL is an extension of the HTML5 Canvas object that uses the JavaScript programming language to display interactive 3D graphics within any compatible web browser - without the need for plugins. This means an explosion of hardware-accelerated 3D all over the web. What does this mean for BIM? Imagine being able to view, annotate, and edit your BIM from any device using the same browser-based user interface. There have been some demos that show WebGL running on Android devices and It is expected that the next generation of Safari on the iPad will support WebGL as well. This will give users a predictable, consistent and accessible interface for 3D tools on any device from PCs to tablets to phones and beyond. This will also allow software vendors to create true web-based 3D applications that are by their nature cross-platform (without having to re-write code.) I know it has been said before, but I predict that this is a tipping point in the history of 3D on the web.

If you are running one of the newer browsers, check out some of these sample works particularly relevant to BIM. Note: You will need to enable WebGL in your browser.

 

Fractal Lab, C'mon, its fractals that you can explore in 3D. Pretty damn cool.

PhiloGL allows you to explore parametric geometry equations.

Tessellations!  Exporting to an OBJ file is a nice touch.

Thingiverse.com is an online community where makers share their 3D creations. Any entry that has an STL file will have a little gray cube icon. Click and you get a 3D preview - with no plugins!

 

3DTin is a Lego style modeler. You build 3D models by placing colored blocks. It is quite primitive (literally), but demonstrates a good start towards interactive 3D modeling on the web.

 

_tom

 

Tips from the Trenches - Enhancing Your Sky

 

Time again for another Tip from the Trenches. Thanks again to Emmanuel Di Giacomo, BIM Technical Advisor CSE based in France.

Enhancing Your Sky

 

Basic 3D views are very simple to achieve and can be really attractive. But did you know that you could enhance then by 2 or 3 simple clicks? Just adding an artificial sky…

Let's see how to achieve that with the project below.

To start, first click at the bottom of your 3D View window on the "Shadows button" on select the "Graphic Display" item from the drop up menu.

The Graphic Display options dialog box will then appear. Just check the "Gradient Background" check box in order to activate the sky visibility.

You can also change the default Sky colors by clicking on the "Sky Color" button. The Horizon color will be the second gradient color. Let's for example change the sky color as shown below.

Here's the kind of result that you should get. Nice isn't it?

Can you remember this request a few years ago for having the ability to put this kind of Gradient background on an elevation view? Well, this is not directly possible but we have an easy tip that will help you achieve it. Read details below.

Switch to your 3D axonometric view.

On your Full Navigation Wheel, click on the small arrow located at the bottom, then choose the "Orient to View" item and finally select the "South Elevation" (for example) item.

The view will be correctly oriented.

You can hide the section box by right clicking on top of it and "Hide in View > Element". You can also activate the "Drop Shadow" Options.

Once the shadows activated, you can proceed as in our first step on the perspective view. This is what you should approximately get.

You can then drop this view on a Sheet. The only issue is that you won't be able to get the Level symbols and to annotate it.

To do so, you will have to superimpose 2 views on a printing sheet. One Standard Elevation View with all its annotations as shown below + one Axonometric oriented view with its gradient background.

+

To get the Gradient Background View empty, and be able to position on a Print Sheet, you'll have to deactivate all categories except floors, and hide all upper floors. Just keep the ground floor in order for Revit Architecture to understand that the view is not empty.

Then, create a Print Sheet, whatever format is needed for your project. Drop your 3D empty view on top of it.

Revit Architecture will propose you to center your currently being dropped elevation view exactly at the place it should be with the help of some intelligent flashing axis, see below. Release the mouse button once you're OK.

This is what you should get. You can now refine your presentation by redefining the crop limits of your Gradient Background. Just activate the view and set it correctly.

Like this…

And this is the final result!

 

DWF Improvements

In this entry I would like to focus attention to what was done to another mechanism for visualization of Revit Models - Export to DWF.

Prior to the 2010 release, our DWF implementation was divided into two parts: 2D export was done through our graphics engine and 3D export was done independently by traversing the model and trying to "guess" what are the correct attributes for every node in the scene graph. This was leading to a lot of errors and justified user complaints about the output quality. Because of this and other problems, we didn't have the ability to combine 2D and 3D data into one file.

After a lot of requests from our users we were given the task to redesign and improve the DWF export to comply with the following five goals:

• WYSIWYG for 2D and 3D views
• Support for 2D and 3D data exportable to a single file
• Export Room and Area geometry for 3D Views
  
• An improved user interface (UI) for selecting, managing, and previewing what is being exported (see image above.)
  
• Apply this new UI consistently among the different export to CAD functions within Revit. (DWG, DXF,  DGN, SAT)
  

 

We were able to achieve those goals, although though there are couple of items left for improvement. I hope those changes will be helpful to our users and their everyday work.

_tsvetan

Tuning the Graphics Engine

Hello, My name is Tsvetan Tsvetanov, Principal Software Engineer with AEC Solutions User Experience Team at Autodesk. Until recently I was part of the Graphics Group working on Revit and I would like to shed some light on work that was done to improve graphics performance in the 2010 release.
As in any software development there are requests that lead to creation of new functionality and others that are are considered "renovation." In this release we implemented a few changes that may not be immediately visible. These changes are pretty big and will open doors for possible feature enhancements for our graphics output. Our graphics engine is tightly coupled with our geometry engine. That way, we are able to allow our geometry data to define the behavior or our graphics visualization, for example the color change when you hover or select an element. This makes the graphics engine very flexible and allows us to define states and conditions for when and how something would be processed by the pipeline (the algorithms that determine how things will appear on the screen.) But in the same time it is limited by the fact that such flexibility can comes with a performance cost.

So what did we do this release ?

One of the biggest, yet mostly invisible changes this release was the shift to a new graphics engine that allowed us to support DirectX together with OpenGL. Along with that, we have started to cache our graphics data so we can send it directly to the graphics hardware without a need to pre-calculate it on every single view update. This should lead to better performance depending on the hardware in use. This performance gain might not be immediately noticeable. For example, when the cache is originally created or when there is not enough memory and we start to clean it, there is an initial performance hit. However, subsequent displays of a cached view should be noticeably faster (once again, depending on hardware.)

This development effort was done to create a framework and mechanisms that will allow us to work on future user-requested enhancements for our graphics output and functionality. These improvements are already noticeable in the current release and should improve the speed with which you navigate views in Revit.

Has this been consistent with your experience with the release to date?