Ralph Grabowski with Dmitry Ushakov: The State of MCAD: BricsCAD Platinum, 2018

Ralph Grabowski with Dmitry Ushakov: The State of MCAD: BricsCAD Platinum, 2018

Reproduced from upFrontEzine Newsletter, Issue #961


by Ralph Grabowski with Dmitry Ushakov

During the Bricsys International Conference 2017 in Paris, Dmitry Ushakov presented a history of MCAD, and explained why his company is doing things differently from the rest of the industry. Mr Ushakov is the ceo of Bricsys Technologies Russia. 

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Dmitry Ushakov presenting at Bricsys International Conference in October

Dmitry Ushakov: Let me first remind you that exactly 30 years ago, 30 September 1987, there was an event that completely changed the face of our industry. A math professor had immigrated to the United States in 1974, and after ten years of work at ComputerVision, he had started his own company. He called it Parametric Technology Corporation with the goal to create a conceptually new CAD product. His goal was to reduce the cost of making design changes.

The idea was to exploit design history. Whenever a designer performs a 3D model operation, the CAD system automatically records it in the history tree. This tree is visible to the user, who can edit its parameters. [When the parameters are changed,] the geometry is regenerated and a variation on the design is produced.

His idea was brilliant, but the downside to this technology was discovered. The downside is a serious problem: every element in the history tree depends on the elements created before it. If a previous element is deleted or deeply modified, then later elements cannot be regenerated. The designer is forced to recreate them from scratch. In the worst case, the designer has to recreate the whole model from scratch. This is not acceptable, and this is not the only problem with history-based modeling.

The whole idea of associating design history with design intent is wrong. The same model can be designed in many different ways, and design intent should not depend on one particular way.

In particular, regeneration times can be long. You cannot wait for design changes that are not foreseen by the designer or customer. There are many other limitations, yet 30 years later we still see this technology on the market.

We see that the approach of Pro/Engineer is successful [using the history tree], as are Solidworks and Inventor. They really gained a big share of the market, but it was a Pyrrhic victory, because you cannot start your design in one system [such as Pro/E] and continue in another one [such as Solidworks]. You cannot jump design intent between these systems; you can only translate dumb geometry.

The impossibility of editing geometry originating in different systems is a very limiting factor, because today every company works in a multi-CAD environment. You are not isolated; you work with your suppliers, with partners, with your customers. All them use their own CAD systems. You have to be able to work with foreign geometry.

It was this situation that raised the renaissance of direct modeling. Now we can find direct editing operations in almost every history-based CAD system. This is a very strange mixture, because every direct editing operation is automatically captured and recorded in the tree. When you change parameters, when you regenerate the geometry, these “direct editing” operations are applied again. It makes the whole process even more complex. It makes it more difficult for the users.

When Bricsys decided to enter the 3D mechanical design market, we had to make a choice:

  • Either implement another history-based system which would be incompatible with any existing ones and would repeat all known conceptual mistakes of this paradigm
  • Or else exploit a new technology developed by a Russian company, LEDAS, variational modeling — a geometric modeling kernel with a variational constraints solver

LEDAS developed a very powerful constraints solver which allows you to put constraints on the boundaries of a geometric model, such as faces and edges. When you apply a push-pull or move-face operation, it can react intelligently with respect to the constraints. In this way, you can parameterized any geometry, even if you don’t have access to its history.

This paradigm opened up new horizons in making 3D models. Bricsys acquired the technology from LEDAS, together with the development team, and this lead to a burst of BricsCAD development. What really makes our solution unique?

First of all, we removed the barrier between imported and native geometry. Any geometry can be edited intelligently, its intent captured automatically, and expressed as geometric and dimensional constraints and local features.

BricsCAD substituting a motor from Solidworks in an elevator assembly

Because we do not regenerate geometry (we use only local operations to update it), our changes are fast and robust. In BricsCAD, you never need to recreate your model from scratch. This is a serious difference from any other CAD system.

It is true that BricsCAD is a direct modeling system. But if you compare it with any other direct modeling system, you will find a lot of differences. The most important one is that we are smart. If you push-pull something, you do it with respect to adjacent elements. This is not possible in other systems.

Being unique, of course, doesn’t mean we completely rejected everything that was invented before. We just repeat it in our own way. In BricsCAD you will find all key tools you expect in a mechanical design system.

MCAD in Six Years

We started [MCAD] just six years ago. We first released a direct modeling tool set with 3D constraints. With that, we implemented the foundation of mechanical design for complex models using assemblies, sub-assemblies, using external components, using thousands of standard parts, with the possibility of assigning materials to compute mass properties, and so on.

Then there was a move to sheet metal, because nearly every mechanical product you can see around you contains sheet metal parts. It is impossible to do mechanical design without sheet metal. We started that four years ago, and now it is a separate product which out-performs any competitor, especially in its ability to rework imported geometry.

Unfolding sheet metal with BricsCAD Platinum

In the same year, we introduced BricsCAD Communicator. It is a very important product for us, because we can edit imported geometry intelligently — as intelligently as in native form. We can import CAD files in native formats, such as Solidworks, Inventor, Solid EdgeCreoCatiaNX, as well as in neutral formats, such as STEP, IGES, and Parasolid. Independent of the file format, they can be intelligently edited in BricsCAD.

Of course we all work in 3D, but we have to produce manufacturing instructions in 2D. We generate drawing views, which are updated automatically when the model is changed.

In AutoCAD there is support for dynamic blocks. These blocks are limited to 2D geometry. In BricsCAD, they are not limited; you can create parametric components for 2D drawings and for 3D, as well. You can use 2D constraints or [in BricsCAD Platinum only] 3D constraints.

Surface modeling is another tool set which is unavoidable in any mechanical design system. BricsCAD supports the creation of surface models using standard tools, but we also support a special tool set called “deformable modeling,” which allows you to smoothly deform any complex shape, independent of its topology. This differentiates us from other CAD systems, because they typically require that control points be moved. This is not a solution when you have complex topology, such as a surface that consists of several faces. In BricsCAD, you can do that.

Last year, we introduced our 3D compare tool, which lets you compare two 3D models and find all the differences. It doesn’t matter which CAD system was used to modify these models. You can create the model in Solidworks, and then edit it in BricsCAD, and then compare the original from Solidworks with the edited one from BricsCAD. It will find automatically all differences, because it does not depend on design history.

What’s New in BricsCAD Platinum V18


  • Exploded views

Direct modeling

  • Copy features, like holes, between parts, including from imported geometry

Parametric components

  • 3D constraints of entities inside associative arrays, useful for repetitive elements, like bearings and stair cases
  • Design tables define allowable combinations of parameters, such as from international standards

Drawing views

  • BOM [bills of material] balloons linked to parts and part tables
  • Exclude from sections, such as standard parts

Exploded assembly linked to BOM through balloons

Sheet metal

  • Automatic parameterization
  • Smart split
  • Ribs along curves
  • Extruded parts

Communicator (translator)

  • PMI import (product and manufacturing information)


What Ralph Grabowski Thinks

Thirty years after its introduction, history-based MCAD continues to be profitable. Pro/Engineer (now Creo) is part of the $1.1 billion/year in sales enjoyed by PTC. Solidworks has millions of users due to speedy annual growth, reported as 12% in the last year.

Mr Ushakov outlined a series of problems that users of history-based MCAD experience, yet they continue to be successful. I would like to put forward several reasons for the on-going success.

  • History On Their Side. Having been around for 30 years, history-based is considered to be the standard approach in MCAD. Designers are no more likely to switch away from it than writers would switch away from Word; Microsoft’s word processor suffers from inherent flaws, as does history-based MCAD, but everyone uses them anyhow.

Even though most MCAD vendors offer direct-editing (or a guise of it), it is not yet mainstream, and so Bricsys is offering an as-yet non-mainstream solution, even though it works well.

  • Pre-CAD not Real CAD. The catalyst for the renaissance in direct editing, Space Claim, emphasized its adjacent-seat status. Their marketing positioned Space Claim as pre-CAD and after-CAD software — before the “real design work” was done by Solidworks, and then afterwards to clean up history-based CAD’s screwups prior to the model arriving on the CAM floor.

The message stuck: direct editing is meant for before and after the real work done by history-based CAD. While the marketing from Bricsys emphasizes all three stages — pre-design, real-CAD, and clean-up — I feel that the message is not yet sticking.

  • Get ‘Em While They’re Young. Companies who sell Solidworks, Solid Edge, and Inventor are prime movers in the post-secondary education industry, backing up millions of free licenses with free multi-media training materials. (Autodesk says it cost them $100 million.) Every day, students learn how to use “30-year-old” history-based MCAD, and then once they understand how to use one system, they easily switch to another, because they all work the same.

Bricsys has little presence in the education market.

  • Do As I Say. Even if students learn direct editing in school, it does not matter once they start working at a manufacturing firm. They use the software they are given, and the software they are given is most likely going to be history-based MCAD.

Bricsys has a small market share, with the number of users estimated between 250,000 and 650,000, and so is not a major presence at manufacturing firms at this time.

  • I Paid A Lot For My Degree. There are psychological angles, too. Engineers spend a lot of time and money to learn history-based MCAD. They expect their software to be complicated and hard-to-use, otherwise anyone could do their job.

The Bricsys ease-of-use trope goes against that meme.

  • If It’s Expensive, It Must Be Good. In some cultures, using tools (and driving automobiles) that are expensive is a sign of importance.

Bricsys has emphasized the low-cost of BricsCAD, and so psychologically it may be seen as not as serious as expensive MCAD. It is time to retire that analog, as Bricsys is increasing its prices. At at the top end, their MCAD system now costs $2,490 for the Platinum base product, Sheet-metal and Communicator (translation) add-ons, and one-year support.

Bricsys executives tell me they are winning the battle on the ground. Locally, distributors and dealers are converting firms to BricsCAD. And it’s not for the negative reasons I listed above, but for another negative reason: Autodesk insistence in forcing subscriptions on unwilling customers is forcing customers to take a look at the alternatives. It is here where Bricsys gets its growth, in addition to the abilities it put into BricsCAD.

About Rakesh Rao

Director, DesignSense Software Technologies Private Limited, Bangalore Proprietor: Four Dimension Technologies CAD Developer, Product development, reseller management,
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