New Adobe R&D lets you edit 3D models via brush strokes

Adobe’s online session from Siggraph 2021, previewing upcoming features in its Substance 3D tools and new graphics research. The section on controlling parametric models via brush strokes start at 13:20.

Adobe has posted a demo of an interesting new research project that lets users edit parametric 3D models simply by clicking and dragging on them in the viewport.

The system, which has obvious potential applications to the new modelling toolset in Substance 3D Designer, was livestreamed at Siggraph 2021, although the recording has only just been posted online.

Edit parametric models directly in the viewport using a brush-stroke-based system
In traditional parametric modelling systems, users adjust the form of a model by editing numeric values or dragging control sliders for indidvidual parameters.

Adobe’s system, set out in the research paper DAG Amendment for Inverse Control of Parametric Shapes, offers a more intuitive approach.

It uses a brush stroke metaphor for editing parametric forms, with the user simply clicking on a model in the viewport and dragging it out into the appropriate shape.

The underlying technology interprets how the user wants to modify the model automatically, based on where on the the model they click, and the width of the brush cursor.

In the demo scene shown above, a narrow brush radius makes it possible to reposition the controls on the toaster’s surface without changing its shape; a wide brush changes the proportions of the entire toaster.

Works with pretty much any parametric modelling system
The system works by modifying the underlying direct acyclic graph (DAG) determining the form of the model, adding extra control nodes to the graph based on the user’s brush strokes.

The method is agnostic to graph’s internal logic, so it can be used with standard node types used in parametric modelling tools, like primitive generators, deformers, Boolean operators and layout controllers.

According to Adobe principal research scientist Tamy Boubekeur, the paper’s co-author, it can be used in parallel with manual parameter editing and is “robust” to changes in geometry or topology.

So when can I expect to see it in commercial software?
At present, the new control system is simply a R&D project: Adobe hasn’t confirmed when, or whether, it will be incorporated into any of its commercial applications.

However, it has obvious potential applications in the new parametric modelling toolset introduced in Substance 3D Designer 11.2 earlier this year: itself initially shown off as an R&D project.

Boubekeur even shows Substance 3D Designer at the start of the demo, providing a pretty clear hint as to where Adobe plans to take the new technology.

Read more about the new brush-based control system for parametric models in Adobe’s research paper