This presentation from Blender Diplom, delivered by Frederick Steinmets and Gottfried Hofmann, introduces a project funded by a German foundation to enhance virtual teaching for the HFK Bremen (University for Fine Arts and Music) following the COVID-19 pandemic. The core challenge for the fine arts department was to establish persistent, open-source, interactive 3D exhibition spaces for student works, particularly sculptures, requiring high-quality visual representation and audio integration. They adopted Mozilla Hubs, which, despite initial discontinuation by Mozilla, found new life under a community foundation. The presentation highlights two significant advancements: the "Behavior Graph" system, a node-based visual scripting tool for complex interactivity based on an early GLTF standard draft, and a "light baking" solution that pre-calculates physically accurate lighting from Blender's Cycles engine onto textures for high-quality static illumination within Hubs. Both features are currently experimental but aim to standardize interactive 3D content and achieve more visually rich web experiences.
Re-Imagining the Internet: 3D Interactivity for Virtual Exhibitions
0:29 Project Introduction: Frederick Steinmets and Gottfried Hofmann from Blender Diplom discuss their project, funded by a German foundation, to create an interactive 3D internet, specifically for virtual teaching at HFK Bremen (University for Fine Arts and Music).
1:17 Remote Learning Challenge: During the COVID-19 pandemic, 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, emphasizing 3D exhibition spaces with high-quality audio and live streaming.
2:40 Open-Source & Hubs Choice: The university prioritized an open-source solution for longevity, selecting Mozilla Hubs. Despite Mozilla discontinuing Hubs, the project continued under the newly formed, community-managed Hubs Foundation, validating their open-source decision.
3:32 Virtual World Design: The virtual environment starts with a realistic replica of the HFK Bremen's physical entrance, transitioning into more abstract and open spaces where students can freely design and showcase 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 (for movable objects), and video playback.
6:59 Introducing Behavior Graphs: The key new development is the "behavior graph" system, a visual scripting interface akin to Unreal Blueprints or Unity Visual Scripting. It enables complex interactivity without traditional programming, based on an early draft of the Kronos Group's GLTF standard.
8:00 Vision for GLTF Standard: The goal is a future where entire interactive 3D applications could be stored in a single, universally interpretable GLTF file, enabling portability across different platforms and web environments.
9:03 Behavior Graph Mechanics: Behavior graphs are "flow"-based, meaning nodes execute only when triggered by events like "On Start," "On Tick" (for animations), "On Interact" (player click), or "Player Collision Enter" (entering a zone). Variables can be stored on objects to manage states or perform calculations.
11:25 Behavior Graph Examples: Demonstrations include interactively opening and closing a door with a click, and synchronously changing textures and mannequins by broadcasting commands to multiple objects via a custom trigger.
13:17 Light Baking for Realistic Lighting: The second major development is "light baking." This process pre-calculates complex, physically accurate lighting from Blender's Cycles render engine onto textures, providing high-quality, static lighting "for free" in Hubs environments at runtime, although it can lead to large file sizes.
15:09 Experimental Status: Both the behavior graph and light baking features are currently experimental, residing in development branches and pull requests, with hopes for integration into the main Hubs release 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 explore the virtual exhibition room via a provided QR code (16:57) for chat and exploration.
The speakers address whether their tool could replace the discontinued Blender Game Engine, stating current logic is limited but hoping for better integration with other game engines like Godot, allowing logic creation in Blender and execution elsewhere.
The idea of in-world (VR) editing of behavior graphs is discussed, suggesting it would be more suitable for Hubs' existing "Spoke" editor rather than the Blender content creation side.