Design Engineering

Mobile CAD

By Ralph Grabowski   

CAD/CAM/CAE Android AutoCAD Autodesk CAD iOS mobile smart phone tablet

As hand held devices gain in performance, running CAD on tiny screens has its appeal but still faces challenges.

12-sept-mobile-CAD-AutoCADWS-360CAD software operating on mobile devices is not new. Companies in the late 1990s, like Graebert, already had simple 2D CAD systems running on PDAs (personal digital assistants), precursors to today’s smartphone.

But drawbacks were serious enough to preclude mobile CAD from becoming common, due to low screen resolution and mere megabytes of memory.

Fast forward to the iPhone which defined the new generation of mobile devices. Today, numerous CAD vendors are releasing apps for Android and iOS devices, but I consider them to be tentative steps. Most are just 2D/3D viewers. Some add mark ups and the ability to toggle layers or select viewpoints, but none are full blown CAD systems.

With such powerful hardware, why the weak software? There are reasons why CAD vendors cannot issue an AutoCAD LT for iPad.


Challenges in Mobile OSes
Smartphones and tablets run many operating systems, but only three are suitable for CAD:

Google Android: largest market share but also the most fragmented; it runs on many devices from hardware companies, since the source code is freely available.

Apple iOS: second largest marketshare but is limited to hardware from Apple; it cannot be licensed and many details closed to developers.

Microsoft Mobile: falling market share and runs on some devices; it’s licensed at cost and most details available.

Not viable operating systems include Nokia’s Symbian (nearly dead), Intel-supported Meego (a.k.a. Moblin and Maemo), and RIM’s OS (losing

Now, let’s look at the problems faced by CAD vendors:

OS Woes: Developers tend to write for iPhone and iPad tablet first, even though Android has twice the market share, because Android suffers from fragmentation. The operating system is freely available, and so anyone can modify it, resulting in hundreds of variations. When Google issues updates, it can be too much work to modify the mods. Google is fixing fragmentation slowly; nevertheless, new releases of Android aren’t on even relatively new devices, whereas Apple is good at supporting old devices.

Apple’s iOS is not resolution-independent, and so developers write apps twice, once for lower resolution iPhones and again for higher resolution iPads. Android adjusts to any resolution of any screen.

Apple users must go through the company’s App Store and apps cannot be “side loaded”; CAD vendors cannot launch iOS software on their own timetable (they have to wait for Apple’s approval), nor can they issue updates quickly. Android allows apps to be installed from any source.

CPU Incompatibility: The primary problem that the ARM CPU used by nearly all smartphones and tablets is its incompatibility with Intel CPUs used by desktop computers. Therefore, CAD vendors have to write much of their software from scratch.

In one attempt to overcome the problem, Intel is porting Android to Atom CPUs. Microsoft with Windows 8 Mobile wants to make it easy to port desktop apps to ARM CPUs.

Small Working RAM: Available RAM has a hard limit, as little as 256MB (in early iPhones). Desktop Windows has paging (data too big for computer’s memory is moved to the hard drive temporarily) that’s not available on portable devices. The CAD program, drawing data, and other running programs all have to fit inside of 512MB or 1GB of memory.

With time, the limits will lift; Samsung is showing 2GB models. In contrast, Apple doesn’t report RAM amounts, leaving developers to guess at what’s available.

Generally, portable devices cannot display drawings in original CAD formats, because the files are too large. Nearly all CAD vendors convert files to a more compact form, stripping out unneeded information. Some CAD systems use the Save As command to convert files for portable devices, as does GStarCAD. Others save drawings to the cloud, which does the conversion (as with AutoCAD WS).

Human Interaction: Portable devices require that we use our relatively fat fingers to navigate. How to see the drawing under our finger? GStarsoft’s MC uses a bird’s-eye view window, while Samsung is reintroducing the stylus to some tablets. Most CAD software, however, involves only viewing and so fat-fingered editing is not an issue.

Touchscreens detect five to ten simultaneous touches, but there is no touch-motion standard beyond drag-to-scroll and pinch-to-zoom. Even panning is inconsistent.

Semi-Accelerated Graphics: ARM CPUs include a GPU component (named “Mali”) for displaying graphics quickly, but it OpenGL ES has limited support for the OpenGL graphics used by most desktop CAD programs. This limits the types of 3D shaded modes used, but ehancements to Mali and OpenGL ES should make 3D graphics faster next year.

Benefits to Mobile CAD
With many drawbacks to CAD on portable devices, why bother? “We are willing to give up functionality for portability,” explains Vectorworks CEO Sean Flaherty. Smartphones let us view drawings on devices we have with us all the time.

Ease of Access: In my home town, a new mall is being built, and when I met the project manager, he pulled out his iPhone and showed how AutoCAD WS let him view any detail drawings to resolve construction issues. He was excited by this.

CAD apps tend to be integrated with cloud storage, like DropBox and GMail. Provided we keep project files in our desktop computer’s cloud folder, we can bring up the most recent versions of files, without having to carry multi-gigabytes versions on our phones, or even bother with remembering to refresh old copies with new ones.

Free Pricing: The way that Apple structured its app store caused a freefall in pricing. The low 99-cent prices benefit us, but are hard on CAD vendors who have programmers to pay.

To overcome the pricing problem, some CAD vendors tie mobile apps to their desktop software. Vectorworks allows access only to subscription customers. Autodesk hints at charging for AutoCAD WS with more features.

An exception is IMSI/Design, who charges as much as $30 for its TurboViewer Pro, which includes advanced functions like cloud-translation from some 20 formats.

The Future
The future of computing is defined by faster and cheaper, but we are only good at predicting the future linearly, and so we don’t know the twists faster and cheaper will take. Just think: three years ago, the iPad didn’t exist.

From the next year’s specs being touted this year, we can expect portable devices that make full CAD a near reality. But, today, portable CAD software is mostly for viewing drawings. We can expect more in the future, right? Well, it’s just that portable technology zigs so fast that we cannot predict where it will zag next.

Ralph Grabowski is a CAD journalist and the author of 140 books on computer-aided design. Check out his CAD industry blog at


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