Open Design Alliance Takes DWG Where Autodesk Doesn't

Issue #952

 

by Ralph Grabowski A flurry of last-minute attendees forced ODA ceo Neil Peterson to find a larger meeting room at the hotel in Prague. This comes as no surprise to me. As Autodesk goes off in a direction that a million or so customers don't want to follow, alternatives to AutoCAD are looking ever more attractive and ever more plausible as replacement seats.  Some of the 130 attending this year's ODA conference in Prague Nearly all competitors to Autodesk -- large and small -- depend on the Open Design Alliance to provide some of the core software needed for users to transition away from Autodesk, whether accessing DWG and RVT [Revit] files, or employing compatible APIs [application programming interfaces] and proxies. As a result, the ODA has become the Microsoft of the CAD world. Using pre-written APIs means programmers have a lot less work to do. They don't need to write from scratch the code that draws dialog boxes or saves data to files; Microsoft and Apple have already done that for them. In the same way, the ODA provides a number of APIs to CAD vendors, and the programmers have less work to do, like figuring out how DWG files store data. If your CAD software opens DWG files, exports models to 3D PDF, or opens point clouds, then you probably have the ODA to thank. And so it is that the competitors to Autodesk come each year to Prague to find out what the ODA has developed this year, for them to add to their CAD programs next year. Day 2 of the conference is devoted to CAD and ODA programmers meeting one-on-one. Looking across the Vltava River towards Old Prague TIP: When visiting Prague, the best thing to do is wander down side alleys to avoid the hordes of tourist groups that now plug up the pedestrian-only streets of the old city. Admire the beautiful buildings and scenes on the nearly-empty back streets, get yourself lost by taking random turns, and then use Google Maps to find your way back again.     Opening DWG Way Beyond DWG DWG is the .docx format of the CAD world, a format that is structured to contain 2D drawings, 3D models, and any kind of other data. While Autodesk admits that the use of DWG is universal, it hasn't made it universal among its own offerings. Competitors like ODA member Bricsys are doing exactly that, extending DWG to define entire buildings and sheet metal parts parametrically. And so is the ODA. It's also expanding DWG in ways Autodesk isn't.  Now, rumors floating about that Autodesk will one day abandon DWG, that it is working on a replacement, that it might be cloud-based, perhaps a database in a manner similar to the Enovia-based 3Dexperience from Dassault. Databases seem to be meant to discourage translation to competitors' formats. I've been asked, "Might a new form of DWG be a risk for AutoCAD workalikes?" Well, no. Autodesk can go in any direction it wants, leaving behind dozens of competitors who will continue to work with DWG, happily. It's a format that's protected: It's a worldwide standard It's a repository of a billion designs It's infinitely extensible  There is no future jeopardy in relying on DWG.   What ODA is Adding to DWG Having understood that there is no future dead-end, the ODA has began to expand the functionality of DWG in ways that don't risk compatibility. Let's look at what these are: Version Control. This is like a very flexible undo-redo system. Instead of being a linear undo then redo, version control lets you branch off in different directions with the design, like this: You save the progress of your work every so often Restart from any saved state to develop two or more versions in parallel Merge version 1 back into a master drawing Merge version 2 into the master at a later time The version history and DWG data are stored in a repository file. A 100%-compatible DWG file can be generated at any point along the stored version history. (No version-keeping data is stored as extended data in the DWG file itself.) At least a couple of ODA member CAD vendors plan to implement version control, and release their software with it next year.   Sneak peak of what version control (colored lines at left edge) looks like in CAD software that's based on Teigha   If you've seen version control in Onshape, then you have a good idea of what the ODA has done. That's because Onshape helped the ODA develop it for DWG. AutoCAD has nothing like this. I've urged the ODA to introduce version control carefully. Users need to be educated how to use it. It can't be like layouts, which were plopped into AutoCAD 27 years ago, and still today too many users create the views they want to plot in model space, and not layouts.  Multi-user Editing. Version control lends itself to giving DWG multi-user editing capability. This is where two or more people work on the same drawing, typically in a networked or cloud environment. Each works on the drawing locally, then the changes are merged into the master DWG file stored on the server. ODA's implementation permits an unlimited number of branches. The closest to this we have today is xrefs -- externally-referenced drawings, which other people can edit; when they save their changes, other users who are referencing the drawings receive alerts from AutoCAD. Conflict Resolution. A third aspect of version control handles changes coming in from multiple users. One user, say, changes a circle to 30mm, the other to 15mm. The ODA implemented conflict resolution like this: the users are presented with both, and then have to agree which change to implement -- kind of like with drawing comparison software. Visualize API. The ODA has turned the rendering portion of its Teigha API into an independent module. When the ODA speaks of "rendering," they don't mean photorealistic renderings of 3D models; they mean the utilitarian tasks that need to be done on the screen: Zoom, pan, orbit, and other view changes Overlays, such as cursors, trackers, and snap points Partial graphics cache regeneration (for faster display of large drawings) Lineweights and line styles Metafiles for hatches, text, and block references Spatial filters to cull entities not on the screen Multi-threaded metafile preprocessing It also handles what we are used to calling "renderings": Wireframe, hidden lines removed, shaded, and other render modes Visual styles such as silhouettes, hidden edges, and transparency Materials Output to 2D and 3D PDF files. This new API is meant for viewing data in files that isn't stored in DWG format. It could be used for file viewers or markup software of simple x,y,z data, ACIS SAT (3D models defined by ASCII data), point clouds, and so on.   Solid modeling options. Autodesk offers ShapeManager for 3D modeling, although other modelers can be hooked into AutoCAD. ODA offers three solid modelers to its members: It's own admittedly aging ODA Modeler, free ACIS from Dassault Spatial, royalty-based  C3D from ASCON C3D Labs, fixed fee Three different paths towards solids modeling with Teigha    What's New in Teigha DWG 2018 In addition to updating Teigha to DWG 2018, the ODA added the following features: Digital signatures (Autodesk removed them from AutoCAD) More than 256MB of data per object Associative center lines and marks Associative surfaces Support for RCP files, point clouds which come from 3D laser scanners As ODA adds functions to Teigha on the desktop, it makes them equally available for the cloud version. This allows members to choose which they prefer to implement: desktop-only, cloud-only, or both. Teigha for the cloud uses Web Assembly format to reduce the library size and speed up function speed. An Update Manager displays only as much of drawings as needed, to minimize the amount of data that needs to be streamed from the server, over the Internet, to the Web browser.  ODA plans to add multi-threaded analysis and optimized GPU rendering to Teigha Cloud. They have three organizations working together to optimize cloud use: Onshape, Graebert, and ODA itself.   What Ralph Grabowski Thinks The ODA has been around for 19 years, says Mr Peterson. "We want to keep this data accessible for another 50 years or more." Best of all, ODA is not charging its members more for these DWG-extra features. The organization began when Autodesk would not provide an API for accessing DWG files. (Back then, its ceo said DXF, the ASCII version of DWG, was sufficient.) Autodesk subsequently came out with its RealDWG API, but the vast majority of firms needing DWG access prefer to go with the ODA. The ODA would no longer exist if it didn't have over a thousand firms supporting it. Until recently, the ODA was primarily a documenter of formats, like DWG and DGN. As of last year, it has began a second path: expanding the utility of DWG -- something I approve of heartily. Now it is up to members of the ODA to implement them.  http://www.opendesign.com Next week: Q&A with ODA ceo Neil Peterson [Disclosure: ODA provided me with air fare, accommodation, and some meals.]   And Now the Rest of the News... Some of the most recent posts on my WorldCAD Access blog: ODA Teigha Conference, Day 2 Teigha Cloud SDK Teigha Revision control for DWG New features for Teigha drawings Exporting custom geometry to Revit's RVT format Teigha Visualize: a general purpose graphics engine Teigha Platform at ODA Prague Live blog: Open Design Alliance's 2017 Conference Preview: Teigha Developer Conference 2017 - - - "Think there needs to be a discussion on what 'value' means in subscription world. Adding a bucket, string & scissors to a product suite isn't." -- Martyn Day on Twitter. - - - Designlive and X3DMedia announce DEVELOP3D LIVE USA 2017 will be back at Boston University on 23-24 October, with multiple conference streams on advanced product development and manufacturing technology; also,.40+ exhibitors.Register at http://d3dliveusa.com/ - - -  "New mission for ODA, keeping DWG relevant for the next 30 years." Randall Newtonreports from Prague at gfxspeak.com/2017/09/12/a-new-mission-for-the-open-design-alliance/ - - - Question at ODA Teigha conference: Is 32-bit still relevant? Audience: "Unfortunately, it still is." "Still needed for another ten years." - - -  Siemens PLM Software is no longer holding one big Solid Edge Universityanymore. Not really a surprise, as only about 500 showed up each year. Instead, as of this year it is holding smaller, regional events throughout the USA and rest of the world. Or as Siemens calls it, "Going global." https://www.plm.automation.siemens.com/en/about_us/events_webinars/solid-edge-university/ - - - LEDAS announces their new cloud platform for CAD-using firms who don't want their IP stored on the servers of strangers. LCP is to be shown in public later this fall: http://www.tenlinks.com/news/ledas-announces-platform-for-building-cloud-cad-apps/ - - - Discovery Live real-time FEA software from ANSYS runs only on GPUs from nVidia. But now AMD tells me that they are investigating it to run on their GPUs. - - - The new release of DIALux evo 7.1 light planning software performs calculations more quickly. The software is free and has 680,000 users. https://www.pressebox.de/pressemitteilung/dial-gmbh/Faster-results-when-planning-with-DIALux-evo-71/boxid/870436 - - - For late-breaking CAD news, follow upFront.eZine on Twitter at @upfrontezine. Letters to the Editor Thank you very much for keeping us abreast of what the world has to offer in this CAD industry!       - Arthur Gan  Love your newsletter.      - Todd Majeski   Thank You, Readers! Thank you to readers who donate towards the operation of upFront.eZine: Thomas Enzmann, Switzerland Holly Stratford, USA Should you wish to support upFront.eZine through PayPal, then the suggested amounts are like these: $25 for individuals > paypal.me/upfrontezine/25 $150 for small companies > paypal.me/upfrontezine/150 $625 for for large companies > paypal.me/upfrontezine/625 Should Paypal.me not operate in your country, then please use www.paypal.com and the account of [email protected]. Or mail a cheque (US$ or CDN$ only, please) to upFront.eZine Publishing, Ltd., 34486 Donlyn Avenue, Abbotsford BC, V2S 4W7, Canada.   Notable Quotable "Smart cities? Tell it like it is: they're surveillance cities."      - Chris Mellor, The Register     http://www.theregister.co.uk/2017/09/07/smart_cities_are_surveillance_cities/ *6615