CSS2DRenderer and CSS3DRenderer are renderers designed for integrating HTML and DOM elements into a Three.js scene. Unlike the WebGL renderer that draws 3D objects directly, these renderers allow DOM elements (like divs and spans) to be placed and moved within the scene, making it possible to include traditional web elements like text, buttons, or even complex UI components directly over or within your 3D world.
CSS2DRenderer is ideal for flat, overlay-like text that stays fixed to the camera’s perspective, appearing as a 2D element on top of your scene.
CSS3DRenderer enables 3D HTML elements to rotate and scale in sync with 3D objects, creating a more immersive effect. These HTML elements move and rotate with the scene, allowing you to make HTML elements part of the 3D world.
Use Case: Useful when you need to render text that doesn’t need to interact with the scene’s lighting or shadows. For example, labels that hover over 3D objects, or user interfaces in games, VR, and AR applications.
Advantages:
Easy to style and control via CSS.
Can be dynamically updated with JavaScript without the overhead of re-rendering.
Fully responsive, making it ideal for flexible layouts.
Great for 2D annotations, labels, and HUDs.
Limitations:
Text and DOM elements are not affected by scene lighting or post-processing effects like bloom or shadows.
Does not integrate into the WebGL rendering pipeline, meaning it remains a separate layer.
Example Scenarios:
In an architectural visualization app, you might have floating text labels that describe rooms or features as users navigate a 3D building.
In a data visualization application, floating labels that follow the 3D objects like graphs or nodes, providing real-time information as the camera moves.