This presentation from Blender Diplom, featuring Frederick Steinmets and Gfred Hoffman, details a project funded by a German foundation to digitize teaching for the HFK Bremen (University for Fine Arts and Music) during the COVID-19 pandemic. The core challenge for the fine arts department was to create persistent, open-source virtual exhibition spaces for student works, particularly sculptures, with high-quality audio integration. They chose Mozilla Hubs, initially facing its discontinuation by Mozilla but later seeing its revival through a community foundation. The presentation highlights two key development areas: implementing an interactive "behavior graph" system (similar to visual scripting in game engines, based on an early Kronos Group GLTF standard draft) for complex user interactions, and developing a "light baking" solution in Blender's Cycles engine to achieve high-quality, static lighting within Hubs environments. While both features are currently experimental, they represent significant steps towards a more interactive and visually rich 3D internet.
Summarizing the Reimagination of the Internet: 3D Interactivity for Virtual Exhibitions
0:29 Project Introduction: Frederick Steinmets and Gfred Hoffman from Blender Diplom introduce their project, funded by a foundation, to reimagine the internet with 3D interactivity, focusing on virtual teaching for the HFK Bremen (University for Fine Arts and Music).
1:17 The Challenge of Remote Learning: During COVID-19, the HFK Bremen received a grant to digitize teaching. While the music department focused on streaming, the fine arts department needed virtual showrooms for sculptures and other works, aiming for 3D exhibition spaces with high-quality audio and live streaming capabilities.
2:40 Open-Source Philosophy & Hubs Choice: The university specifically sought an open-source solution to ensure longevity, opting for Mozilla Hubs. They faced an initial challenge when Mozilla discontinued Hubs, but the project continued with the formation of the community-managed Hubs Foundation, proving it a "right decision."
3:32 World Design Concept: The virtual world design begins with a realistic replica of the HFK Bremen's physical entrance, transitioning into more abstract and open spaces where students can freely create their exhibitions.
4:14 Existing Hubs Capabilities: Hubs already offered basic interactive components such as animated water, UV scroll effects, particles, links to other rooms or web pages, audio playback, rigid body physics (allowing objects to be moved and simulated), and video playback.
6:59 Introducing Behavior Graphs: The core new development is the "behavior graph" system, a visual scripting interface (similar to Unreal Blueprints, Unity Visual Scripting, or Godot Visual Script) that allows complex interactivity without traditional programming. This system is based on an early draft of the Kronos Group's GLTF standard, aiming for a future where entire interactive 3D applications can be stored in a single, universally interpretable GLTF file.
9:03 Behavior Graph Mechanics: Behavior graphs operate on a "flow" principle, where nodes execute only when triggered. Key triggers include "On Start" (initialization), "On Tick" (every frame, for animations), "On Interact" (player click), and "Player Collision Enter" (player entering a defined zone). Variables can be stored on game objects to define states, share animations, or perform calculations.
11:25 Behavior Graph in Action (Examples): A demonstration shows interactive elements like opening and closing a door with a click, and navigating through a list of textures and mannequins that change simultaneously when an arrow is clicked, showcasing broadcast functionality across multiple objects.
13:17 Light Baking for Realistic Lighting: The second major development is "light baking," which pre-calculates complex, physically accurate lighting from Blender's Cycles render engine onto textures. This provides high-quality, static lighting in Hubs environments "for free" at runtime, crucial for showcasing sculptures, though it can result in large file sizes.
15:09 Experimental Status: Both the behavior graph and light baking features are currently in experimental branches and pull requests, not yet fully integrated into the main Hubs release, but the team hopes for inclusion by the September Blender conference.
15:48 Live Demo & Call to Action: A live demo showcases current capabilities, including door interaction and gaze-based interaction. The audience is invited to visit the virtual exhibition room via a QR code (16:57), allowing them to chat and explore the space.
17:50 Q&A - Future of Blender Game Engine & In-World Editing:
When asked if the tool could replace the discontinued Blender Game Engine, the speaker stated that the logic is currently limited but expressed hope for better integration with other game engines like Godot, allowing logic to be created in Blender and run elsewhere.
The possibility of in-world (VR) editing of behavior graphs was raised, to which the speaker suggested it would fit better within Hubs' existing "Spoke" editor rather than the Blender side, which focuses on content creation.