The Future of Technical Drawing (rev 1)

Why talk about technical drawing at all? Why think about its past, or reflect on its current state? Why try to envision its future? Or imagine it even has a future, when it’s typical these days it seems part of the standard discourse in some circles — to dismiss the future of technical drawing, to doubt it even has a future, any future whatsoever.

But it does! I describe it here:

World << >> Focus INTERPLAY


A 35 second film clip by the film maker Jim Cummings powerfully illustrates world < > focus interplay. You recognize yourself in this clip, how YOU develop understanding, of the world, and the targets of your focus, each through the other, the world through focus, the object of your focus contextualized in the world. It’s interplay:

Screen Shot 2018-11-25 at 5.52.04 PM
film clip posted on Linkedin by Jim Cummings: video link

Interplay is fundamental.

The pairs are in continuous interplay:

  • Wide / Narrow
  • Environment / Focus
  • Film Set / Attention-Focusing camera rig
  • Model / Drawing

Interplay generates understanding and is the basic observable dynamic of thinking.

Digital innovation investment in the AECO industry has for decades been weighted toward the wide, the whole, the expansive environment (the model), while the other half of the interplay tandem — technique of articulate narrowing focus (drawing) — stagnates.

The imbalance is counterproductive.

The purpose of digital media

The purpose of continued development of digital media is to assist with thinking. Let’s assert that.

The purpose of innovation in digital media is to make media a more energetic and able companion to thought and understanding. The goal of continued development is to expand and enhance media’s support for clear, coherent, timely, thought. Effective media helps the mind at work arrive on target, at cogent understanding.

The Future of Technical Drawing: Evolution in Form

A look at drawing’s future, characteristics of drawing’s proposed new form of expression, in models:

  • drawing should be immersed in-situ at true orientation within modeled environments
  • drawing should exist also ex-situ, abstracted out of modeled environments
  • ex-situ and in-situ, drawing should easily, elegantly, flow from one to the other (ex, in), and back, looping on demand
  • in-situ, drawing should be persuasively interactive. Drawing should compel users to engage because they draw one into models by delivering insight and clarity with enough communicative power that work becomes fun, building understanding becomes something one does for the delight of doing so
  • drawing should fully exploit the tremendous available power of digital modeled environments
  • drawing should be visually clear and powerfully communicative
  • drawing should exploit film industry camera rigging: Scroll through those hundred camera rigging techniques. It’s a treasure trove. High time already that digital modelers in the AECO (Architecture, Engineering, Construction, Operations) industry make use of it, not on the periphery of practice but at the core.
  • drawings should define their range scope (scope box/volume) within a model
  • drawing should include a built-in camera rig viewing path. The drawing author selects from a library of predefined paths, or defines it directly. Subsequently, those viewing the drawing can view it along this viewing path. Like the play timeline on youtube videos, for example, the viewer can drag the viewing position forward or backward along the camera rig viewing path.
  • Along the camera rig path, various graphics controls are specified by the drawing author, including:
    • show/hide (filter) model graphics. The technical drawing author can specify the use of different graphics show/hide filters at different positions along the camera rig path
    • elements in motion – motion is optional and can be used for example to show complex model element assembly sequence or “exploded view” presentations. These can be displayed progressively, along the built in camera rig path
    • extra graphics like embellishing/completing lines and arcs, text notes, labels (oooh the continued need for automation of these….), dimensions, stylized symbolic textures/patterns are authored and can be made progressively visible along the camera rig path, their purpose to highlight and clarify what’s visible from the camera rig
    • a camera transformation from perspective to parallel projection, the latter (parallel) provided as preset path options to be applied where the camera rig approaches a viewing angle normal to the target plane of interest in the model, usually at or near the center of the TGN rig built-in camera path.
    • an I/O to and from other graphics apps and formats in common use including illustration, CAD, and other graphics formats. In this way, technical drawing in its new form retains a callback to legacy format and presentation. The old and the new inform each other and interact fluently.
  • drawings should be portable so that drawings authored in one modeled environment are portable and may be shared with others in other modeling apps and platforms, and expressed there with fidelity.

The Future of Drawing: TGN – a model INTERACTIONS format standard

Characteristics of drawing’s future, listed above, are specified in detail as a proposed new model INTERACTIONS format standard: TGN. Links to download the TGN developer specification are given below. The video shows some of the look and feel of this new form of technical drawing, TGN:

03 TGN: demonstration  (3:40)

2021 TGN rig demo

TGN Developer Specification DOWNLOAD

TGN developer specification download links:

TGN: a digital model INTERACTIONS format standard (Apple Book)

TGN: a digital model INTERACTIONS format standard (ePub)

TGN: a digital model INTERACTIONS format standard (iCloud)

There are important aspects of TGN missing from the demo video. The shortcomings of the demo are discussed in self-critique here:


The playlist includes other TGN videos (of me, basically) discussing TGN for developers (technical considerations), and value to users (typical workflows):

0 1 TGN: rigging for insight  (2:16)

02 TGN: what is TGN exactly?  (5:35)

03 TGN: demonstration  (3:40)

04 TGN: portability  (5:17)

05 TGN: industry value  (9:27)

The dev platform I mention in the videos is iTwins.js, but TGN can be developed on every platform where TGN is desired. The TGN demo shows a building model composed of several models obtained from different engineering disciplines (structural, architectural, civil/site, electrical, etc.). TGN is intended for development on all app platforms that support 3D modeling formats.

Not the first time

This is not the first time I proposed evolution in drawing’s form. The first time was back in 2006. I proposed automatic presentation of complete CAD drawings at true orientation within models. The idea floated by one day (I grabbed it), after years of building detailed digital building models myself, and, those same years (since 1998), driving construction drawing graphics from those models.

It took awhile, but I was eventually employed by Bentley Systems (some great luck) and led the team that designed, developed, and in 2012 first commercialized what came to be called “hypermodel” in Bentley’s MicroStation, which automatically presented all construction drawings in-situ within the models, like this:

2012 hypermodel, Microstation, automated drawing-model fusion

More examples of first generation drawing-model fusion: here 

Seven software companies since 2012, that I know of, are now doing automated drawing-model fusion (first generation), since 2012: Bentley, Graphisoft (in BIMx Docs, mobile), Dalux, Revizto, working together: Morpholio and Shapr3D, and now Tekla too.

TGN is for everyone, every platform

Now 10 years later, TGN is richer than hypermodel:

  • better expression, more engaging use of graphics potential
  • more compelling interactivity, better control, and more controls
  • clearer communicative impact
  • more authoring power and greater viewing comprehension
  • designed for cross platform portability

TGN promises improvement in technique for the close study of complex modeled environments.

As the TGN specification and proposed technical infrastructure is intentionally not confined to any single application or platform (a no silos approach), and instead is freely available for all to use, TGN has the potential to increase the utility of modeled environments of all kinds, and to spur new creative energy by amplifying the communicative power of digital modeled environments. This is what TGN is about.

The purpose of innovation in digital media is to make media a more energetic and able companion to thought and understanding. The goal of continued development is to expand and enhance media’s support for clear, coherent, timely, thought. Effective media helps the mind at work arrive on target, at cogent understanding.

I’m available to help

I’d like to help any (every) developer organization design their implementation of TGN to make best use of the capabilities of each modeling platform, and at the same time to plan for standardized cross-platform portability of TGN.

Message me on LinkedIn:

Or email:

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