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Inventor

What’s New in Inventor 2016

March 31, 2015 By Barb Schmitz Leave a Comment

Autodesk introduced the newest version of its desktop 3D CAD product, Autodesk Inventor 2016, which provides a trio of modeling tools: parametric, direct editing and freeform design tools. Inventor 2016 also enables users to associatively connect their Inventor data to non-native CAD formats so their electrical and mechanical data can be integrated into one single design environment.

Work More Efficiently in Multi-CAD Environments

New to Inventor 2016 are features that facilitate working with files and models created in other CAD systems. An associative import of CAD data from CATIA, SolidWorks, NX, Pro-E/Creo, and Alias files allows users to maintain a link to the selected file. The imported geometry in Inventor updates as the model changes.

In addition, a selective import support allows users to only read in the geometry that is vital, speeding the import process. The new Select tab provides you the option to specify which objects to import when importing a CATIA, SolidWorks, Pro-E/Creo, NX, Alias, STEP, IGES, or Rhino file.

Multi-thread support has been enabled, which allows Inventor to more efficiently use available hardware, resulting in improved performance when working on files from other CAD systems. The options for importing CATIA, SolidWorks, Pro-E/Creo, NX, Alias, STEP, IGES, Rhino, SAT, Parasolid Binary files have also been simplified and provide clear choices for import.

With this new version, users can quickly insert an AutoCAD DWG file in an Inventor part file as a DWG underlay using the Import command in the 3D Model tab, Create panel. Users can also now add assembly relationships to underlay geometry.

The Project DWG Geometry command can be used to project DWG geometry, polylines, open or closed loops, and DWG blocks, then the projected sketch elements can be used to create modeling features. 3D Inventor models based on the DWG geometry will update when the 2D geometry changes in AutoCAD.

Autodesk Inventor 2016 now offers an associative import of CAD data from CATIA, SolidWorks, NX, Pro-E/Creo, and Alias files that allows you to maintain a link to the selected file. The imported geometry in Inventor updates as the model changes.
Autodesk Inventor 2016 now offers an associative import of CAD data from CATIA, SolidWorks, NX, Pro-E/Creo, and Alias files that allows you to maintain a link to the selected file. The imported geometry in Inventor updates as the model changes.

Mechanical and Electrical Interoperability

The new Electromechanical link between Inventor and AutoCAD Electrical provides a smooth data exchange between 2D and 3D electrical designs. When users create a link between an AutoCAD Electrical and an Inventor assembly, the project files become associative, meaning that design data changes made in one product are updated in the other via Sync.

The Location View command on the new Electromechanical tab on the Assembly ribbon in Inventor displays the devices and wiring contained in both the AutoCAD Electrical Drawings and Inventor Assemblies.

Creating Shapes

Powerful new commands and workflows are now available in Inventor’s Freeform modeling environment. Users can now work with open surfaces or closed shapes; convert existing model faces to freeform geometry for shape refinement; delete faces; unweld edges to split and move a freeform body segment; and use the Freeform Thicken command to create solids, offset surfaces, or shell walls.

3D Printing

A new environment is added that lets users position and orient their design within the print space of the selected 3D printer. Users can also update the part in the print environment that does not impact the source document. When finished, users can send the results to Print Studio or other printing software to begin printing the part.

Users can now position and orient their design within the print space of the selected 3D printer and update the part in the print environment that does not impact the source document. When finished, send the results to Print Studio or other printing software to begin printing the part.
Users can now position and orient their design within the print space of the selected 3D printer and update the part in the print environment that does not impact the source document. When finished, send the results to Print Studio or other printing software to begin printing the part.

Drawing Enhancements

Drawing view creation has been simplified, and uses in-canvas tools. Text formatting is expanded with new options: Bullets and numbering, strike-through text, enhanced formatting (all caps, title case, lower case). Surface texture and feature control frame symbols are updated to the latest standards.

Many new graphical symbols are available, and can be inserted in various types of drawing annotations. Balloon styles can use custom balloon shapes. A new Single Segment Leader option allows users to create drawing annotations with a single leader segment and align drawing annotations vertically, horizontally, or to an edge. Users can create a view sketch on a model with included work features and select those work features with the Project Geometry command.

With a new external Sketch Symbols Library, users can quickly access and share their collection of sketch symbols. The Library is an Inventor drawing file that, by default, is located in a subfolder of the Design Data location of your project. This new feature offers the following new functions:

* A search and filter feature in the Sketch Symbols Library dialog box.
* Preview the sketch in a preview pane within the dialog box before placing the sketch.
* Browser expansion state remains throughout session when placing sketch symbols.
* A Sketch Symbol Library can be created in IDW and DWG formats, allowing insertion of symbols contained within the library file from either format.
* Save your sketch symbols to a customized library.

Visualization

All lighting styles in Inventor Studio are now associated with an Image-Based Lighting (IBL). A lighting style can have zero local lights but must have one IBL. IBL-based styles provides better lighting sources in Inventor Studio with enriched IBL collection.

When users enter the Studio Environment, all legacy local lights are now disabled by default. It is recommended that users utilize IBL for better rendering results. All newly created lighting styles are associated with the default IBL automatically. Change the associated IBL to another IBL as desired.

The enhanced visual effect for shaded visual style makes it more consistent with the realistic visual style. The rendering engine in Inventor Studio was changed to RapidRT with advanced configurations for better quality rendering.

The Studio Render Illustration settings have been moved to the View tab. The new and enhanced Technical Illustration command creates a realistic illustration effect in the graphics window.

Workflow Enhancements

Among the many enhancements, are:

General

* Use Escape (Esc) key to cancel an operation in select processes.
* Multiple productivity enhancements made to dialog boxes.
* Add all window tile styles to the task bar.
* Dock an Inventor browser on any application’s window edge.
* Hide all sketch dimensions now available in the Object Visibility menu.
* Import/Export external rules configuration for iLogic (not available in Inventor LT).

Sheet metal parts

* Multi-body support is added to sheet metal.Support for zero bend radius is added to many commands.
* Material thickness is detected when you convert a part to a sheet metal part.
* Punch tool shows a count of the center selections.

Tube and Pipe setting enhancements

You can now customize file names for fittings and populate part numbers into your parts list within the drawing environment. Previously, you could only change the name of your conduit items, but now you can update fittings as well.

Parts

* Face draft contains powerful new options that let you Fix or Move the parting line.
* Ruled Surface is added to the surfacing commands.
* The Mirror and Pattern commands support multiple solid body selection.
* Previously, nonlinear patterns of a solid body in a multi body part file have not been possible. You can now create nonlinear patterns for solid bodies.
* Drag a sketch above the parent feature in the browser to share it.
* The Measure command now allows you to measure an angle to the midpoint of any segment. This option is achieved by hovering your mouse over the midpoint of a segment until a yellow dot appears.

Sketch

* Identify which workplane or face a sketch was created on.
* The selected Show All or Hide All Constraints display setting remains active as you sketch and throughout your editing session.
* Create tangent dimensions between circular or arc geometry within a 2D sketch.
* The Initial View Scale property of the first drawing review placed on the sheet is added in the Sheet Properties group within the Format Text dialog box.
* The Sketch Dimensions option is added to the Object Visibility list. Select this option to display 2D or 3D sketches and hide all related sketch dimensions.
* Sharing a sketch is made visible by dragging above the feature in browser.
* New snap points added to the context menu: Endpoint, Apparent Intersection, Quadrant, and Mid of 2 points.
* Modify Start Sketch and select a view or sheet before sketching.

Assembly

* New safety factor calculation warning displays in Stress Analysis.
* The Midplane option has been added to the assembly Pattern command. Select the Midplane option to create a pattern distributed on both sides of the original component.
* Replace All feature available for highlighted components within an assembly.
* Select multiple sick constraints within Design Doctor to delete.

Drawings

* Start a drawing from any open model, and automatically apply the current model camera and representations in the base view.
* In-canvas tools in the Base View command simplify creation of a base view and projected views. For example, you can use the ViewCube to orient the model, set the view scale by dragging a view corner, or adjust projected views while creating the base view.

For more detailed information on all the new bells and whistles in Autodesk Inventor 2016, check out its Help Page.

Barb Schmitz

Filed Under: Autodesk, Inventor, News Tagged With: Autodesk

GrabCAD Announces Integration with PTC Creo and Workbench Summer 2014 Release

June 18, 2014 By Barb Schmitz Leave a Comment

It appears the folks at GrabCAD have been quite busy. The Cambridge-based startup is making two significant announcements today: the integration of its Workbench cloud-based file management platform with PTC Creo CAD software and the release of Workbench Summer 2014.

Since PTC Live Global was just held this week in Boston, we’ll start with that one. The integration of Workbench with Creo means that users will now have a host of new capabilities that are available only to PTC Creo users. These new capabilities include:
● The ability to view native models
● The ability to view Creo drawings and other proprietary Creo documents
● The ability to interact with assembly information, such as family table instances

In addition, the processing power for all of the above actions will be provided by the GrabCAD cloud platform, freeing up the user’s desktop for other tasks. GrabCAD and PTC will roll out these new capabilities over the next several months to both new and existing PTC Creo and Workbench users.

“PTC Creo is the CAD tool of choice for many of the companies that use Workbench, whose users appreciate the ability to access an integrated set of design, simulation and manufacturing tools in one suite,” said Hardi Meybaum, founder and CEO of GrabCAD. “We’re excited that this integration with PTC Creo will make it even easier for these users to keep track of CAD files and bring others into their design process quickly and easily.”

GrabCAD Workbench is a cloud-based file management platform that makes it easier for users to manage and share CAD files.
GrabCAD Workbench is a cloud-based file management platform that makes it easier for users to manage and share CAD files.

Summer Release 2014

The company also announced that July 1st it will ship its Summer Release of GrabCAD Workbench. Already boasting CAD file management and external collaboration features, Workbench makes it easy for mid-sized companies to better deal with CAD file management.

The Summer Release’s new capabilities include:
● Flexible search capabilities. Search on metadata such as date, type, author, revision, version, and custom file properties
● “Whereused” reports. Shows where a part is used in other assemblies
● Assembly BOM Views. Display, filter, and export the parts list of any CAD assembly
● Configuration and family table support. View different configurations and families of parts and assemblies from major CAD systems

Many engineering organizations rely on more than one CAD provider, so Workbench is designed to support them all. This “multiCAD” approach is supported by a number of new CAD-specific enhancements:
● SolidWorks. Intelligent notifications alert users of document changes such as when a file is locked or affected by changes to another document
● Creo. Automatically detects the latest Creo file for upload; view native parts, assemblies, and drawings
● Autodesk. Support for 3D DWG

In addition to these new features, GrabCAD has made more than 100 enhancements to existing features over the last six months, including:
● Revision control. Links assembly revision to part revision
● Version control and backup. Restores deleted files or restore to a point in time
● File locking. Lock status now available inside SolidWorks Workbench add-in

Learn more about GrabCAD Workbench by clicking here.

Barb Schmitz

Filed Under: Creo, Inventor, News, SolidWorks Tagged With: Collaboration, file management

Luxion Releases KeyShot 5 Rendering Software

June 2, 2014 By Barb Schmitz Leave a Comment

Rendering software is increasingly being put to use by design engineers to create downstream product collateral used to support, maintain and sell products–often before the product even exists in physical form. Rendered 3D models are also created and used early in the design process to speed the process of obtaining customer or management approval.

Rendering vendors are working hard to make it easier for users to import 3D models and have incorporated features specific to the the way engineers work. After all, the engineering workflow is quite different from those of users in the arts and entertainment markets.

Read more on rendering software in the Design World feature A Picture’s Worth a Thousand Words: Why Rendering is Increasingly Important to Product Development.

KeyShot 5 for rendering and animation

Luxion has recently released the latest version of its KeyShot rendering software, touted to be the first real-time ray tracing and global illumination software. By providing faster rendering speed and capabilities, users can create images, animations and interactive visuals throughout the product development process quickly and easily.

KeyShot 5 introduces enhanced usability and pro-level features that allow engineers, designers and 3D professionals to make their workflow more efficient and take their visuals to the next level. The software’s new streamlined interface offers new features for a faster rendering and animation workflow, the ability to work with materials faster and more powerful new animation features.

New features in KeyShot rendering software enable engineers to make their workflow more efficient and take their visual assets to the next level.
New features in KeyShot rendering software enable engineers to make their workflow more efficient and take their visual assets to the next level.

What’s new?

KeyShot Cloud. Online library where users can download new resources and share their own custom assets. Opening the KeyShot Cloud enables easy drag-and-drop downloading of new resources into their local KeyShot Library, and quick search features and filters to find the perfect resources for a scene. All resources remain on a user’s computer with a copy of the resource uploaded to the KeyShot Cloud and no scene or personal info stored online. The KeyShot Cloud is accessible directly from inside KeyShot and online here.

NURBS Ray-tracing. NURBS ray-tracing delivers more accurate geometry with smoother edges. This new import feature gives users the option to import and render NURBS geometry from their favorite 3D modeling application. The advantage is crisper visuals and smaller file sizes over data imported as triangle that can display edges and gaps on close detail shots. NURBS import is currently available for all geometry formats, including Creo, CATIA, Inventor, NX, Rhino, SolidWorks, Solid Edge, STEP, IGES, Parasolid and ALIAS. Available with KeyShot Pro versions.

Instancing. Instancing allows users to duplicate parts in KeyShot and on import without increasing file size. Instancing of parts is available within KeyShot as a Pattern tool and completely automated in select KeyShot plugins. All instances can be treated separately for quick appearance studies or linked to apply materials quickly, but will all update when LiveLinking or update geometry is used.

Fade Animation. The new Fade animation allows users to quickly apply an animation that fades parts from one opacity level to another. Through KeyShot Animation users add individual transforms that add animations with a click of a button instead of managing keyframes. Just as simple, Fade animations can be applied while adjusting the opacity of parts and groups on-the-fly which allows users to see the update in real-time as animations are created. Available with the KeyShot Animation Add-on.

Sun & Sky System. KeyShot 5 introduces a new Sun & Sky system for automatic creation of physically accurate geographic lighting. Preset resolutions and locations together with day selection, time and turbidity sliders allow the creation of unlimited daylight scenarios. Custom Sun & Sky environments can be created by users as well and combined with other lighting options available in the KeyShot HDRI Editor. Available with KeyShot Pro versions.

KeyShot 5 is available now. Pricing starts at $995. The entire list of features in KeyShot 5 can be seen and downloaded in a What’s New guide that includes information on how each feature works.

Barb Schmitz

Filed Under: Creo, General Blogs, Inventor, Rhino, Siemens PLM, SolidWorks Tagged With: animation, rendering

The failed promise of parametric CAD, final chapter: A viable solution

November 18, 2013 By Evan Yares 5 Comments

Model reuseWhat is the failed promise of parametric CAD? In short, model reuse.

It’s a lot more difficult than it ought to be, for a variety of reasons. Several months back, I wrote a series of articles discussing those reasons, as well as some of the solutions that have come up over the years.  What was missing from the series was a final chapter; a detailed description of what could prove to be a viable solution to problems with model reuse: the resilient modeling strategy.

The resilient modeling strategy (RMS) is the brainchild of Richard “Dick” Gebhard. I wrote about Dick last June, in the article A Resilient Modeling Strategy. He’s a low-key guy with deep experience and serious expertise in the practical use of MCAD software. Over his career in CAD, he’s been a reseller for CADKEY, Pro/E, and most recently, Solid Edge.

RMS is a best practice for creating CAD models that are stable and easily reusable (even by inexperienced users.)  It can be learned and easily used by typical CAD users, it preserves design intent in models, and provides a mechanism by which managers or checkers can quickly validate a model’s quality.

Resilient Modeling Strategy

When Dick first started thinking about the concepts that make up the resilient modeling strategy, it was natural that it was in the context of showing the advantages of Synchronous Technology (The Siemens PLM brand name for its version of direct modeling.) In our discussions about RMS over the last year or so, I pointed out that, while I thought that RMS did indeed demonstrate the benefits of hybrid history/direct modeling in Solid Edge, for it to be taken seriously, and not be unfairly dismissed as a marketing initiative for Solid Edge, it needed to work with a wide variety of MCAD tools. I think Dick got where I was coming from, because he’s continued to refine and generalize RMS, with feedback from users of a number of MCAD systems.

In its current incarnation, RMS works particularly well with Solid Edge, as might be expected, but also works very well with Creo, NX, CATIA, and IronCAD (all of which are hybrid history/direct systems.) Further, with a few modifications, it can provide compelling value with SolidWorks, Inventor, and Pro/E (all of which are primarily history-oriented systems.)

It’s significant that RMS is also free to use. While Dick is available to provide presentations, seminars, and training, he has not attempted to patent, or keep as trade secrets, the underlying concepts of RMS. (He does claim a trademark on the term “Resilient Modeling Strategy,” which means that organizations offering commercial training on RMS will need to get Dick’s OK to use the term.)

Dick has posted an introductory presentation on RMS at resilientmodeling.com. While the entire presentation is 20 minutes long, the first 3-1/2 minutes cover the problems that people invariably experience when reusing or editing history-based CAD models. Watching that much will likely convince you to watch the rest.

On Wednesday, November 20, at 10:00 AM PST, Dick will be hosting a webinar on RMS. It’s scheduled to last just 30 minutes, with the emphasis on content, not hype. If you’re a serious CAD user or a CAD manager (or, for that matter, you work for an MCAD developer), it’ll be well worth your time to attend.

TL;DR: Resilient Modeling Strategy is a best practice for creating high quality reusable 3D MCAD models. It works with many CAD systems, it’s easy to learn and use, and it’s free. Big payoff for MCAD users. 

Presentation at resilientmodeling.com

Register for Nov 20 webinar on Resilient Modeling

 

 

 

Filed Under: Catia, Creo, Evan Yares, Featured, Inventor, News, Pro/Engineer, Siemens PLM, SolidWorks Tagged With: 3D CAD, Catia, Dassault Systemes, Evan Yares, Inventor, IronCAD, PTC, Siemens PLM, Solid Edge, SolidWorks

Autodesk Introduces Next Generation Integrated CAM for Inventor

October 7, 2013 By 3DCAD Editor Leave a Comment

After two months in public beta and collecting a wealth of invaluable user feedback, next generation integrated CAM for Inventor is here with the commercial availability of Autodesk Inventor HSM Express.

Last October, Autodesk announced it was entering the CAM market with the acquisition of HSMWorks, a developer of integrated CAM solutions for SolidWorks software. Since then, Autodesk announced their intention to integrate the HSMWorks CAM technology across their entire portfolio of desktop and cloud based design tools. The release of Inventor HSM Express reinforces Autodesk’s commitment to the CAM market and to delivering solutions that appeal to the broadest range of users – from designers and engineers to veteran CNC programmers – regardless of their CAD tool of choice.

Autodesk-Introduces-Next-Generation-Integrated-CAM-for-Inventor

We are excited to be able to provide users of Inventor with the same level of integration, performance, and quality currently enjoyed by users of our HSMWorks and HSMXpress CAM solutions, said Carl White, Director of Manufacturing Engineering at Autodesk.

Autodesk Inventor HSM Express is a free* CAM solution that is seamlessly integrated inside the design environment of Autodesk Inventor software. Inventor HSM Express integrates powerful CNC programming tools inside existing Inventor user interface, providing users with the ability to produce code for CNC machining centers inside their existing Inventor workflow.

The public beta trial of Autodesk Inventor HSM Express had 850+ participants across 56 countries. Highlights from the beta include:

  • 800+ blog posts in the forum asking questions and sharing enthusiasm and tips and tricks
  • Students made up one fifth of overall beta participants
  • 56% of all beta participants classified themselves as designers and/or engineers

What Beta Participants Had to Say:

John Wilson, Skyline Cabinets said, we just purchased Autodesk Product Design Suite and are thinking Inventor might help us with 3D design. If this CAM can be set-up to be used with our machine, I can see great possibilities.

I can’t express my excitement to see Autodesk finally incorporating a CAM utility into one of their pieces of software. I went through the requested tasks for this Beta of HSM Express and I was very pleased. I can’t wait to see how this software will progress, said Thomas Gammon, Elrod and Company, LLC.

It’s great to see Autodesk taking CAM seriously at last, said Dave Whiteley, Envisage UK Ltd.

Autodesk Inventor HSM Express is available immediately, for free, and both English and German languages will be supported.

Autodesk
www.autodesk.com

Filed Under: Autodesk, Autodesk News, Company News, Inventor Tagged With: Autodesk

The failed promise of parametric CAD part 5: A resilient modeling strategy

June 25, 2013 By Evan Yares 3 Comments

bamboo-gardenThe model brittleness problem inherent with parametric feature-based modeling is a really big deal. And it’s something, honestly, that I don’t have a great answer for. I’ve even asked a few power users who I know, and their answers seemed to involve a bit of hand-waving, and a reference to having lots of experience.

While best practices are a potentially good step forward, they need to be straightforward enough that mere mortals (as opposed to power users) can follow them.

Around Christmas last year, I got a call from Richard Gebhard, an engineer’s engineer, who has made his living selling CAD, and training people to use it (including more than his fair share of power users), for longer than he would like me to admit. (I’m pretty sure I’ve been in the CAD industry longer than him, though.) Richard told me he had something he wanted to show me, and if I’d take the time to meet him, he’d buy me lunch.

What Richard showed me was a way of creating and structuring CAD models that made a lot of sense. It not only reduced parent-child dependencies, but it made them more predictable. And, more importantly, it made it a lot easier for a mere mortals to scan through the feature tree, and see if there were any grues (it’s a technical term. Feel free to look it up.)

Over the next several months, we had lunch several times. I made suggestions. He rejected some, accepted some, and thought about others. At the same time, he was bouncing his ideas off several of his best power users (including his son). By a couple of months ago, he had refined his system to the place where it would work impressively well with nearly any parametric feature-based CAD system. So, he went to work finalizing his presentation.

I had mentioned that Delphi, by patenting some of the elements of horizontal modeling, limited the number of people who could benefit from it. (Worse for them, they patented it, then filed bankruptcy. That didn’t help much.) Richard’s goal wasn’t to monetize his process. His goal was to evangelize it. To help CAD users—both power users and mere mortals—to get their jobs done better.

Richard and I had talked, over time, about what he should call this process. At first, I liked the word “robust.” In computer science, it is the ability of a system to cope with errors during execution. In economics, it is the ability of a model to remain valid under different assumptions, parameters and initial conditions. Those are good connotations. But, then I thought of one of my favorite examples of robustness. The first time I visited Russia, I noticed that the apartment buildings were built of thick poured concrete. Very robust. And nearly impossible to remodel.

Richard’s system wasn’t robust. It was resilient. So, he has named it the Resilient Modeling Strategy. RMS.

So far, I’ve written over 2,600 words, to provide some background on the problems of parametric modeling, and some of the solutions that have been offered over the years. But, after all that, I’m not going to tell you anything more about RMS. At least, not yet.

Tomorrow, Wednesday, June 26, Richard will present RMS for the first time ever, at Solid Edge University, in Cincinnati, Ohio. His presentation will start at 9:00AM local time, and will be in room 6 of the convention center. If you’re there, put it on your calendar. If not, you’ll need to wait until Richard gets back to Phoenix, and I publish a follow-up post.

RMS is not anything difficult, or fundamentally new. It’s just an elegant distillation of best practices, designed to work with nearly any parametric CAD system, and simple enough that it doesn’t get in the way.  It’ll help you make better CAD models faster.

Filed Under: Alibre, Autodesk, Creo, Design World, Evan Yares, Featured, Inventor, Pro/Engineer, Siemens PLM, SolidWorks Tagged With: Creo, Inventor, IronCAD, Solid Edge, SolidWorks

The failed promise of parametric CAD part 4: Going horizontal

June 25, 2013 By Evan Yares 12 Comments

In the early 90s, Ron Andrews, a senior product designer at Dephi’s Saginaw Steering Systems Division, became fed-up with the difficulties of editing parametric CAD models. So, he and a team of his colleagues, including Pravin Khurana, Kevin Marseilles, and Diane Landers, took on a challenge of trying to find a solution.

They came up with an interesting concept that they called horizontal modeling. Here’s a description of it from their patent abstract:

“Disclosed is a horizontal structure method of CAD/CAM manufacturing where a base feature is provided and one or more form features added to it to form a model. The form features are added in an associative relationship with the base feature, preferable a parent child relationship, but are added in a way as to have substantially no associative relationships with each other. The result is a horizontally-structured Master Process Model where any one form feature can be altered or deleted without affecting the rest of the model. Extracts are then made of the Master Process Model to show the construction of the model feature by feature over time. These extracts are then used to generate manufacturing instructions that are used to machine a real-world part from a blank shaped like the base feature.”

Here’s a picture that makes it clearer:

Horizontal Modeling

The simplest explanation I can give for it is this: You create a base feature, and bunch of datum (working) planes. You attach all the child features to those datum planes. Viola: no parent-child problems.

I admit that I’m not going to do justice to horizontal modeling in this conversation. There’s actually quite a bit to it, and it makes a lot of sense when coupled with computer-aided process planning (CAPP.)

Horizontal modeling has a handful of problems. First, it does a pretty good job of killing the possibility of having design intent expressed in the feature tree. Next, it works better with some CAD systems than others. (When horizontal modeling was in the news, SolidWorks had a problem managing the normals on datum planes, so it didn’t work too well.) The deadliest problem is that Delphi got a bunch of patents on the process, then licensed it to some training companies. From what I can see (and I may be wrong), none of these training centers offer horizontal modeling classes any more.

While, technically, you can’t use horizontal modeling without a patent license from Delphi, the concepts at its core are fairly similar to things that CAD users have been doing for years. A few years ago, Josh Mings posted on a couple of online forums that “Horizontal Modeling is just one word for it, you may also know it as Skeleton Modeling, Tier modeling, Sketch Assembly modeling, CAD
Neutral Modeling, or Body Modeling.” (It’s actually two words for it, but I get his point.)

Horizontal modeling is not a silver bullet solution for the problems inherent in parametric feature-based CAD. It’s just a best practice—a strategy for getting around the problems. It seems to be headed in the right direction, but it suffers from the complexity that comes from trying to fix too many problems at once.

Next: A Resilient Modeling Strategy

Filed Under: Alibre, Autodesk, Creo, Design World, Evan Yares, Featured, Inventor, Pro/Engineer, Siemens PLM, SolidWorks Tagged With: Creo, Inventor, IronCAD, Solid Edge, SolidWorks

The failed promise of parametric CAD part 3: The direct solution

June 25, 2013 By Evan Yares 5 Comments

Pull-PushDirect modeling—a syncretic melding of concepts pioneered by CoCreate, Trispectives, Kubotek (and many others)–has shown the most promise to cure the parametric curse.

Direct modeling is today’s hot CAD technology. PTC, Autodesk, Siemens PLM, Dassault (CATIA, but not so much SolidWorks), IronCAD, Kubotek, Bricsys, SpaceClaim (and certainly some other companies I’ve forgotten) all have their own unique implementations of it.

The common thread in direct modeling is to use standard construction techniques when modeling, and feature inferencing (or recognition) when editing. It’s easier said than done. It’s taken about 35 years of industry research to get to the place we are today—where you can click on a face of a model, and the system will recognize that you’re pointing to a feature that has some semantic value. And that’s not even considering the tremendous amount of work that has been required by legions of PhD mathematicians to develop the math that lets you push or pull on a model face, and have the system actually edit the geometry it in a useful manner.

For the CAD software, figuring out which way to edit a selection is almost a mind reading trick: A user clicks and drags on a part of a model. What would they like to happen? In some cases it’s easy: Drag once face of a rectangular block, and the system will just make it longer or shorter. But if the block is full of holes, bosses, and blends, it becomes a lot more complicated. What should the system do if you drag a face so far back that it consumes another feature, and then pull it back to where it was? Should the consumed feature be lost forever, or should the system remember it in some way, so it can be restored?

There are no right answers. It seems that no two direct modeling systems handle the decision of what is a “sensible” edit in the same way.

While direct modeling absolutely solves the model brittleness problem inherent with parametrics, it does it by simply not using parametrics. Even with hybrid parametric/direct CAD systems, the answer to the parametric curse is still to not use parametrics when you don’t need to.

The solution of “use direct modeling when you can, and learn to live with parametric hassles when you can’t” just isn’t very satisfying to me.

Next: Going horizontal

Filed Under: Alibre, Autodesk, Creo, Design World, Evan Yares, Featured, Inventor, Pro/Engineer, Siemens PLM, SolidWorks Tagged With: Creo, Inventor, IronCAD, Solid Edge, SolidWorks

The failed promise of parametric CAD part 2: The problem is editing

June 25, 2013 By Evan Yares 4 Comments

ErasermIn the previous post, I wrote about the failed promise of parametric CAD: problems such as parent-child dependencies and unwanted feature interactions, coupled with no easy way to either prevent, or check for them.

The difference between modeling and editing in a parametric CAD system is simply the difference between creating things from scratch, and modifying things you’ve already created. The distinction may seem academic, but it is only when editing that parent-child dependencies are a potential problem.

Consider a scenario, of creating a parametric part—one that you’ve worked out in your head pretty well ahead of time—where you start from scratch, modeling sequentially, and spending all your time working on the most recent feature without needing to go back to edit upstream features.

In that context, the model’s parent-child dependencies would exist, but would be benign. They’d never get in your way. That is, until you went back to edit the part.

In most cases, people don’t build models from scratch without periodically going back to adjust earlier features from time to time. In that process, they’ll catch, and be able to deal with, some of the dependencies. But not likely all, or even most, of them.

I’ve heard experienced CAD people use an interesting term for models with hidden and untested parent-child dependencies: Parts from hell. When you’re trying to modify them, you never know when a small change might cause them to completely fall apart. I think a better, more descriptive, term is brittle: Hard, but liable to break or shatter easily.

This also suggests a descriptive term for CAD models which are not liable to break or shatter easily: resilient.

I’ve only ever seen one group of users who could consistently create complex yet resilient parametric parts models from scratch: PTC application engineers from the early to mid-1990s. Of course, they could only do it during customer benchmarks, with parts they’d practiced ahead of time, where they had worked-out and memorized all the steps, and where they had a good idea of the parameter ranges. Even then, if you were to ask them to change a dimension that would cause a topological change, the models might unceremoniously blow up.

Not to paint too bleak a picture, there are certainly CAD power users who have the skills to create resilient CAD models. I’ve met more than a few of them: true professionals, who by combining experience, insight, and education, have earned the respect of their peers. They understand how to structure CAD models to avoid any problems with brittleness.

Nah. I’m just messing with you. Power users struggle with this just like us mere mortals. It’s just that their models don’t usually fall apart until you go outside the scope of parametric changes they had anticipated. Give power user’s carefully crafted CAD model to a user who has a black thumb (I’m sure someone comes to mind), and they’ll find ways to blow it up that the power user never imagined.

Next: The direct solution

Filed Under: Autodesk, Creo, Design World, Evan Yares, Featured, Inventor, Pro/Engineer, Siemens PLM, SolidWorks Tagged With: Creo, Inventor, IronCAD, Solid Edge, SolidWorks

The failed promise of parametric CAD part 1: From the beginning

June 25, 2013 By Evan Yares 28 Comments

The modern era of 3D CAD was born in September 1987, when Deere & Company bought the first two seats of Pro/Engineer, from the still new Parametric Technology Corporation. A couple of years later, Deere’s Jack Wiley was quoted in the Anderson Report, saying:

“Pro/ENGINEER is the best example I have seen to date of how solid modelers ought to work. The strength of the product is its mechanical features coupled with dimensional adjustability. The benefit of this combination is a much friendlier user interface plus an intelligent geometric database.”

According to Sam Geisberg, the founder of PTC:

“The goal is to create a system that would be flexible enough to encourage the engineer to easily consider a variety of designs. And the cost of making design changes ought to be as close to zero as possible. In addition, the traditional CAD/CAM software of the time unrealistically restricted low-cost changes to only the very front end of the design-engineering process.”

To say Pro/E was a success would be a terrible understatement. Within a few years PTC was winning major accounts from the old-line competitors. In 1992, on the strength of its product, PTC walked away with a 2,000 seat order from Caterpillar that Unigraphics had thought was in the bag.

The secret to Pro/E’s success was its parametric feature-based solid modeling approach to building 3D models. To companies such as Deere and Caterpillar, it offered a compelling vision. Imagine being able to build a virtual CAD model of an engine, and, by changing a few parameters, being able to alter its displacement, or even its number of cylinders. And even if that wasn’t achievable, it would be a great leap forward to just be able to rapidly create and explore design alternatives for parts and assemblies.

Yet, things were not that easy. In 1990, Steve Wolfe, one of the CAD industry’s most insightful observers, pointed out that Pro/E was incapable of making some seemingly simple parametric changes.

Pro/Engineer placed limits on the range of parameters. (A designer could not increase the dimension of L2 to point that L3 vanished.)
Pro/Engineer placed limits on the range of parameters. (A designer could not increase the dimension of L2 to point that L3 vanished.)

David Weisberg, editor of the Engineering Automation Report (and from whose book, The Engineering Design Revolution, I have liberally cribbed for this article), pointed out the fundamental problem with parametrics:

“The problem with a pure parametric design technique that is based upon regenerating the model from its history tree is that, as geometry is added, it is dependent upon geometry created earlier. This methodology has been described as a parent/child relationship, except that it can be many levels deep. If a parent level element is deleted or changed in certain ways it can have unexpected effects on child-level elements. In extreme cases (and sometimes in cases that were not particularly that extreme), the user was forced to totally recreate the model… Some people described designing with Pro/ENGINEER to be more similar to programming than to conventional engineering design.”

Weisberg barely scratches the surface of the issues that can create problems.

In 1991, Dr. Jami Shah wrote an Assessment of Features Technology, for Computer-Aided Design, a journal targeted to people doing research in the field of CAD. He identified that there were problems with features:

“There are no universally applicable methods for checking the validity of features. It is up to the person defining a feature to specify what is valid or invalid for a given feature. Typical checks that need to be done are: compatibility of parent/dependent features, limits on dimension, and inadvertent interference with other features. In a study for CAM-I, Shah et al. enumerated the following types of feature interactions:

  • interaction that makes a feature nonfunctional,
  • non-generic feature(s) obtained from two or more generic ones,
  • feature parameters rendered obsolete,
  • nonstandard topology,
  • feature deleted by subtraction of larger feature,
  • feature deleted by addition of larger feature.
  • open feature becomes closed,
  • inadvertent interactions from modifications.”

The important thing to notice here is that, not only are there multiple failure modes for features, there are also no universal methods for validating features. It’s left up to the user to figure out. And that process, as Weisberg hinted, is much too difficult.

Rebuild Error

Since the early days of Pro/E, a lot of work has been done, both by PTC and other companies in the CAD industry, to improve the reliability and usability of parametric feature-based CAD software. Yet, the problems that Weisberg and Shah identified still exist, and still get in the way of users being able to get the most from their software.

Next: The problem is editing.

 

Filed Under: 3D CAD Package Tips, Autodesk, Creo, Design World, Evan Yares, Featured, Inventor, Pro/Engineer, Siemens PLM, SolidWorks Tagged With: Creo, Inventor, IronCAD, Solid Edge, SolidWorks

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