Order Independent Transparency (OIT) in computer graphics programming terminology denotes any technique that can correctly render overlapping semi-transparent objects without having to sort them before they are being rendered. Rendering semi-transparent objects has always been a problem because the blending operation is order dependent: when a semi-transparent fragment is rendered, the underlying color (i.e. the background) is crucial for the final color to be correct.
OIT is a new option that can simply be enabled in Creo Parametric 2.0. With OIT, Creo Parametric 2.0 allows for pixel accurate rendering of overlapping semi-transparent objects without having to sort them before they are being rendered, providing up to 10 times performance of blended rendering in PRO/Engineer Wildfire 5.0 compared to when rendering transparency in Creo Parametric 2.0. This translates into less time waiting for your model to render and increased productivity over the long run.
This technique is easy to implement and add to an existing rendering pipeline: everything can be rendered as usual, semi-transparent or not. The technique here is fully implemented on the AMD FirePro professional graphics board, which totally frees the CPU from multiple render passes or face sorting. OIT only works with FirePro cards.
OIT assembles a pixel-accurate representation of the model and its surrounding geometry while maintaining user interactivity and visual quality. This creates a more practical transparent 3D viewpoint to continuously work within, helping improve the sense of design intuition and aid in better decision-making throughout the product development stages. It is also very accurate since the actual sorting that happens on the GPU is done per fragment.
The technique has a very low impact on the existing rendering pipeline and is therefore very easy to integrate in an existing rendering engine. As far as performance goes, the results speak for themselves: it achieves up to 10x faster frame rate compared to face sorting and regular blending.
How It Works
The technique is based on the usage of an A-buffer, a simple list of fragments per pixel, in its simplest form as a linked list of fragments per pixel. First, all primitives are rasterized to the A-Buffer, writing some color value and some depth value (Red-Green-Blue-Alpha-Depth), one index buffer (RAT) is used to keep the number of fragments in this pixel. Finally, a full screen shader pass will sort that A-Buffer according to the depth value and do the blending for each fragment according to their sorted indices.
Viewport performance with OIT enabled has been measured to increase up to ten times versus OIT disabled with transparency visual quality dramatically improved with pixel-accurate transparency rendering, solving visual artifact problems and z-ordering issues seen without OIT enabled. AMD developed the OIT implementation for PTC and the Creo Parametric 2.0 community, showing the company’s commitment to the market as an innovator – not just a product company.
Editor’s Note: Q&A with CADspeed answers CAD hardware questions from our readers.
I am the CAD manager for a design group of eight. We are looking into upgrading our computers to be able to accommodate our 3D modeling needs. We primarily use AutoCAD and CADWorx for piping and vessel design. We do not use surfaces or rendering. My question is, what CPU/GPU combination should I be looking into for high performance orbit/zoom/pan/refresh? Our price point is below $2000 and we would like to get a comparable laptop as well.
Answer from CADspeed Blogger, Alex Herrera:
In general, I’d start with a CPU and GPU of relatively equal footing (i.e. both entry class, both mid-range, etc.) Then, if a lot of time is spent navigating/viewing a static model in real time with good render quality, then you’ll want to look for a higher-end GPU. If more time is spent creating models or rendering with final-frame or publish quality, then focusing on a higher-end CPU would be more appropriate.
In Part 1 of this series, I introduced you to the new cloud-based collaboration tool from Autodesk, called Autodesk 360. In Part 2, I am going to show some of the functionality of Autodesk 360.
Once You’re Logged In, What’s Next?
Once you’re set up with your Autodesk ID and you’re logged in, what exactly can you do? What services are available? Well, if I went in to detail, I could write blogs about a mile long that would take you a week to read, so let’s go with something simple.
Autodesk 2013 Product Range
All of the Autodesk 2013 product range now include an Autodesk 360 tab on the ribbon interface. To keep it simple, I will work with AutoCAD 2013 on a PC workstation or laptop to show you how this all works.
Click on the Online tab on the AutoCAD 2013 ribbon interface.
You will see a group of ribbon panels that are grouped and incorporate relevant icons to work with Autodesk 360 from the AutoCAD 2013 application. The benefit here is that you can collaborate from AutoCAD straight to the cloud to other AutoCAD users and, more importantly, other Autodesk cloud users, who may be using other Autodesk products.
A typical example of this goes back to my previous blog series about AutoCAD WS, which features heavily in Autodesk 360 right now. As long as you are logged in to Autodesk 360 (click on the Autodesk 360 icon to do this), using the Share Document icon allows you to share the document (our drawing) in either Autodesk 360 or AutoCAD WS.
Autodesk 360 now updates in your browser, prompting you to Refresh List.
Once refreshed, Autodesk 360 updates your document list, and you can see the new document. In this case, it is an imperial drawing called Autodesk 360.dwg. Autodesk 360 shows you all 5 layout tabs available in the drawing.
So, if I now select one of the layout tabs in the refreshed document (drawing), I can start the collaboration process. As you can see from the screenshot below, I have plenty of tools to work with in Autodesk 360. I can toggle between layout views, I have a thumbnail view and I have zoom and text tools as well.
Now, the tools shown are purely for use in Autodesk 360 but if I select the Actions pulldown menu, I can then start collaborating via AutoCAD WS as well. Clicking on Edit Online in AutoCAD WS opens up another browser tab with AutoCAD WS and providing you are logged in, you can start to work on the drawing using AutoCAD WS.
AutoCAD WS can be used on a number of platforms, as per my previous blog series — PC, Mac, tablet and smartphone to name a few. This is where Autodesk 360 starts to really prove that the cloud will totally change how we work with Autodesk products.
As I have said before, Autodesk will revolutionize the way we work with Autodesk 360. It will allow us to embrace the mobile CAD movement and start to mobilize the CAD office/function in ways we never thought possible.
Stay tuned for Part 3 of this series, where I will start to show you have to synchronize your local/network locations to Autodesk 360.
Author: Shaun Bryant
The incessant pace of progress and innovation for workstation technology never slows.
Less than a quarter after every major workstation OEM launched a full trio of models based on Intel’s Sandy Bridge-EP (a.k.a. Xeon E5), the industry leader in CPUs has already released its follow-on processor generation, code-named Ivy Bridge. And subsequently, we are now seeing the first Ivy Bridge workstations hitting the market, including Dell’s Precision T1650 and HP’s Z220.
How Does Ivy Bridge Affect the CAD Workstation Market?
What benefits can Ivy Bridge offer to those plying their trade in CAD? Well, there’s the usual broad-based boost in performance that any good generational upgrade will provide, as Intel expects a 20 percent performance improvement for general computation from Ivy Bridge (though of course mileage will vary by application). But there’s more appeal for this upcoming product family than just the usual generation-to-generation performance bump. Because while that appeal extends across applications and usage models, there are a few special nuggets of technology in this generation that will pique the interest of workstation-wielding CAD professionals.
Intel’s lead in silicon process manufacturing continues to grow, and the benefits of Ivy Bridge should prove an ideal vehicle to showcase that lead. Just as competitors are getting their 32 nm process, with Ivy Bridge Intel’s jumping a full generation ahead with a 22 nm process that allows for millions more transistors in the same silicon area.
That’s a win for workstation buyers especially, as they represent a professional community that certainly care about CPU performance, but demand a lot more. First off, a shrink buys room for more cores, and we’ll eventually see some Ivy Bridge SKUs with eight or more cores (not at first launch, but later in the product lifecycle). Far from being one-trick-ponies, today’s MCAD professionals have to be jacks-of-all-trades — a competitive market, tight budgets and tighter schedules all demand it. Drawing is just one piece of the daily workflow, complemented by a host of other critical compute tasks, from simulation to styling. And chores like finite element analysis and computational fluid dynamics multi-thread quite well, making 50% more available cores a serious weapon in driving computation time down and achieving the ultimate goal — boosting productivity.
Improved Integrated Graphics
The extra silicon space also allowed Intel to dial up the performance and functionality of its integrated graphics hardware. For example, Ivy Bridge’s P4000 GPU populates more on-chip graphics engines and supports advanced features like hardware tessellation, a proven tool that can deliver finer, more realistic 3D surfaces in less time. With its range of upgrades, Ivy Bridge can claim full DirectX11 support that its predecessor could not. And with more of those bigger, faster graphics engines, Intel can claim a 30% increase in performance for Ivy Bridge’s graphics over Sandy Bridge’s. And that means CAD professionals on a budget can now more seriously consider choosing a low-cost CPU-integrated graphics solution like the P400.
Support for Three Monitors
But looking beyond performance, Ivy Bridge’s graphics is going to provide another big draw for the MCAD professional: native support for three monitors. While the mainstream is now just discovering the benefits of dual monitors, many mechanical designers are already using three: for example, one for drawing, one for simulation and one for visualization. Prior to Ivy Bridge, a desktop with three high-resolution monitors mandated at least one discrete add-in graphics card. But with this generation, a cost-conscious MCAD user could go three-wide and stick with base platform graphics.
MCAD Users: Same Performance, 50% Fewer Watts!
With more cores to speed CAD simulation and ultra-realistic rendering, as well as a 30 percent graphics improvement, Ivy Bridge promises to be a tide that raises all boats, as all workstations — deskside or mobile — will benefit. But there’s one unique advancement debuting in Ivy Bridge that’s a particular boon to the MCAD pro on the go. You see, Ivy Bridge’s 22 nm technology introduces a revolutionary new transistor structure called TriGate that offers the same performance at 50% fewer Watts than Sandy Bridge’s 32 nm.
And that’s allowing leading vendors HP, Lenovo, Dell and Fujitsu to introduce new mobile workstation models that dramatically extend battery life at the same performance level, or deliver far more performance, with the same battery life. Either way you look at it, it’s a win when computation demands are high. And few corners of the computing world demand more performance/Watt than mechanical designers trying to accomplish demanding design work on the road.
This post reflects industry analyst Alex Herrera’s views and does not necessarily reflect the opinions, product plans or strategy of either Dell or Intel.
Processors for CAD Hardware: Find the Balance Between Multiple Cores and Increased Single-Thread Performance
Several years ago processor vendors began backing away from a sole focus on cranking up clock frequencies and otherwise striving to squeeze every last possible bit of performance from single-thread processing. That path was heading down the road of diminishing returns and leading to other problems, most notably excessive power consumption and thermal output.
Growth of Multi-Core Processing
Single-thread performance hasn’t been forgotten, but the dominant thrust has shifted to parallel processing, with Intel moving from dual-core to quad-core and now hex-core processors. Factor in the dualsocket configurations available in mid-range and higher workstations, and today 12 processing cores in a single machine can easily be had.
What Does Multi-Core Processing Mean to the CAD Professional?
Multi-core approaches have proved to be a great way to gain theoretical speed-ups, but for CAD professionals who have practical computing demands, how well reality tracks theory depends on their application. Some CAD software programs, including AutoCAD and SolidWorks, do limited multitasking if multiple processors are available — for example, in managing the user interface and on-screen display. And rendering software, whether running on the CPU, GPU, or both, tends to use multiple processing cores.
Given this, most CAD pros will want to find the right balance of multiple cores and increased single-thread performance, the latter enabled by Intel through a combination of architectural improvements in its CPU design and its Turbo Boost Technology 2.0, which delivers an (often temporary) increase in CPU clock speed.
What Should You Buy?
Although an oversimplification, it’s generally fair to say that if CAD modeling chews up more hours than anything else in your day, you should allocate more of your workstation budget to buying a fast processor. If you spend most of your time rendering, you should invest more of the budget in more cores, or in many cases, a more powerful GPU if that’s what your application needs. Read on.
Where do you draw the line on how much of your budget to allocate to the CPU? Again, there’s no universal answer — sorry, there never is — but keep in mind that the upward climb on this (or nearly any) product spectrum follows a path of diminishing returns. So once you’ve decided whether to favor most cores or fastest cores, try to get a sense of where the “knee” is in the price curve. That is, where do you start paying a lot more to get a comparatively small return? That’s likely to be your sweet spot, tempered of course by the constraints in your overall budget.