Google open-sources GNM Head, its parametric human head model
Google has open-sourced GNM Head, its parametric 3D model of the human head.
The model, which is derived from real-world 3D scan data, provides over 250 controls for generating realistic 3D heads, and over 380 controls for facial expressions.
The release was announced yesterday on LinkedIn by Google Staff Technical Artist and former Walt Disney Animation Studios Lead Character TD Iker J. de los Mozos.
Since then, in less than 12 hours, artists inspired by the news have already created add-ons based on GNM Head for Houdini and Blender, the latter available for free.
What is GNM Head?
GNM (Generative aNthropomorphic Model) – it’s pronounced ‘genome’ – is Google’s new family of parametric models for recreating the human body in 3D.
They’re statistical models, based on real-world 3D scan data, not generative AI tools, and are designed to be anatomically accurate.
The first module to be released within the GNM ecosystem is GNM Head: a parametric 3D model for generating realistic male and female 3D human heads of a range of ethnicities.
It includes separate sets of parameters for generating the base facial mesh – there are separate components for the skin, eyes, teeth and tongue – and for head poses and facial expressions.
There are 253 ‘identity’ parameters – those controlling the basic shape of the head mesh – with 170 for the head itself, 80 for teeth, and three for eyeballs.
These are supplemented by 383 expression parameters: 100 each for the left and right eyes, 150 for the lower face, 32 for the tongue, and one for the irises.
How can CG artists used GNM Head?
In its current form, GNM Head is more for researchers and software developers than CG artists: a resource from which to build artist tools, rather than an artist tool in its own right.
Being open-source, it could be integrated into existing 3D character-generation tools for game development, animation and visual effects work: both free tools like MakeHuman/MPFB and CharMorph, and commercial ones like Reallusion’s Character Creator.
However, in the time it has been publicly available – less than 12 hours, at the time of writing – artists have already developed add-ons based on it for other CG applications.
For Blender users, rigging artist Nathan Dickson – Rigging Lead on Student Academy Award-winning animation Student Accomplice – has released GNM Head Importer for Blender.
The free add-on, shown above, makes it possible to adjust GNM Head’s control parameters using simple sliders, and see the results live on a 3D head in the Blender viewport.
For Houdini users, David Eschrich, Global Head of 3D at VFX firm Zoic Studios, has incorporated it into a HDA, although at the time of writing, it doesn’t seem to be publicly available.
What data is GNM Head based on?
Google hasn’t yet announced exactly what data the GNM Head model is based on, beyond the fact that it was a “large dataset of 3D scans”.
The data uses “binary gender categories and four broad demographic groups”, and does “not fully represent the spectrum of … gender identities or the full diversity of the global population”.
In a comment on LinkedIn, Google Senior Research Scientist Stylianos Ploumpis said that the company planned to release a more detailed report in the “next few weeks”.
Will there be a GNM Body model in future?
Although GNM Head is the first package from the GNM ecosystem to be released publicly, the way that its GitHub repository is laid out suggests that there will be others.
Google also says that GNM “strives to be the most … complete 3D parametric human model” available, as well as the most accurate model.
On LinkedIn, Stylianos Ploumpis confirmed that future releases will take place, but that Google couldn’t currently comment on what or when they would be.
License and system requirements
GNM Head is available under an Apache 2.0 license, making it possible to integrate it into both commercial and open-source software.
Nathan Dickson’s GNM Head Importer for Blender is compatible with Blender 5.1+. It’s free.
Download open-source parametric 3D head model GNM Head from Google’s GitHub repository
Have your say on this story by following CG Channel on Facebook, Instagram and X (formerly Twitter). As well as being able to comment on stories, followers of our social media accounts can see videos we don’t post on the site itself, including making-ofs for the latest VFX movies, animations, games cinematics and motion graphics projects.