From Socrates to the Stars: A Conversational Avatar Platform for Museums and Exhibitions

From Socrates to an astronaut, our conversational avatar platform brings AI-powered characters to life in museums and exhibitions.

Two and a half years ago, we presented the first prototype of “Converse with Socrates”, an interactive AI application that allows visitors to have a real conversation with a digital avatar of the ancient Greek philosopher. The prototype was installed in the exhibition “Artificial Intelligence: Opportunities & Challenges” at the Thessaloniki Science Center and Technology Museum NOESIS, as part of the ArtCast4D first pilot demonstration, where visitors could discuss with Socrates about the impact of disinformation on everyday life. A more refined version of the application followed at the second pilot of the ArtCast4D project in Athens, within an interactive experience on artificial superintelligence, human welfare and the dilemma of decision making. There, two totems with touch screen monitors invited visitors to ask Socrates questions from a list or to engage in an open discussion with him. The application quickly became a favourite of the children and teenagers who visited the exhibition with their schools, so much that NOESIS decided to make it a permanent exhibit at its entrance hall, free and accessible for all.

Last year, the exhibition “Artificial Intelligence: Opportunities & Challenges” and our application “Converse with Socrates” were hosted by JOIST Innovation Park, where about 5,000 children visited them and were fascinated by the chance to talk with the philosopher. JOIST also recognised the value and the impact that this kind of interactive application can have in education, and asked us to create a new version with an astronaut for its upcoming exhibition about space. We took this opportunity to build the application from scratch in Unreal Engine 5.6, this time not as a single application but as a platform. The same functionality can now be used with different characters and environments, which can be customized each time according to the needs of an exhibition.

How it works

The experience is built around two screens. On a large portrait screen, the character appears in life size, standing in a 3D environment designed around its story. Next to it, a touch screen works as a control panel: visitors choose between Greek and English, tap one of the suggested questions, or press and hold the microphone button to ask anything they like in their own words. While the character answers, subtitles appear under it, and a stop button lets visitors interrupt it at any moment and move on to their next question.

Each character is created with MetaHuman, the technology of Epic Games for highly realistic digital humans, which is now available directly inside Unreal Engine 5.6. Starting from reference portraits, we shape the face, skin, hair and body of the character until it looks exactly the way we imagine it. Its clothes, from the space suit of the astronaut to the chitons of the philosophers, are fitted on the body with MetaTailor, a tool that dresses 3D characters and adapts the garments to their movements, so that the clothing follows every gesture naturally. Finally, a set of body and facial animations keeps the character alive even when it is simply listening.

The voice and the “brain” of each character are powered by Convai, a platform for conversational characters. When a visitor speaks, Convai turns the speech into text, uses a large language model to prepare an answer in the personality of the character, turns this answer into a realistic voice, and drives the lipsync, so that the lips and facial expressions of the avatar match every word it says. Each character has its own personality, background story and knowledge base, which we prepare together with the content partners of each exhibition, so that the answers stay accurate, on topic and suitable for young visitors. In the earlier version of Socrates, these steps required several separate services working together; now they are handled by a single platform, which makes the conversation faster and the whole system simpler to maintain.

Everything that makes a character unique, such as its name, its languages, the suggested questions and the texts on the control panel, is kept in a separate profile, so a new character can be created without changing the application itself. Settings like timings and screen layout can be adjusted on site through a simple configuration file, without rebuilding anything. The application is also designed to run unattended for a whole day at a public venue: it recovers on its own if the connection drops, and it returns to Greek and to its idle state after a period of inactivity, so that every new visitor begins with a fresh conversation.

Three characters at the Thessaloniki International Fair

Once the Astronaut avatar was completed and installed at JOIST, we went on to create a new version of Socrates as well as a third character, Aristotle. Together, the three avatars were presented at the Thessaloniki International Fair, showing that our conversational platform is robust and can easily host many different characters. During the two weekends of the fair, visitors interacted more than 1,200 times with the three avatars, and left impressed by the quality of the answers, the state of the art graphics with their detailed animations and lipsync, and the experience as a whole.

What comes next

We recently had the pleasure of attending the opening of the exhibition “Innovation in Space Exploration” at JOIST, during the 2nd Astronomy Festival of Larissa, where we finally saw our astronaut in his “natural space”. Meanwhile, the first version of Socrates at the entrance hall of NOESIS is being replaced with the new one, so that its visitors can enjoy everything the new platform has to offer. We are also in talks with partners to disseminate the platform as a possible exhibit for future exhibitions. We remain open to collaborations with museums, science centres, exhibition organisers and educators, and we look forward to bringing many more characters to life!