In the previous chapters, we've been building our 3D scenes using basic geometric shapes like cubes and spheres that we create directly within Three.js. While this is excellent for understanding the fundamentals, real-world 3D experiences often involve importing more complex and visually rich assets created by artists and designers. This chapter is all about bringing these external assets into your Three.js projects, focusing primarily on 3D models and textures.
Think of it like this: instead of meticulously crafting every brick in a house you're building in a game, you can import a pre-made 3D model of a house. Similarly, instead of drawing every detail on a character, you can apply a texture – essentially an image – to its surface to give it color, material properties, and intricate details. This significantly speeds up development and allows for much more sophisticated visuals.
We'll explore the common file formats for 3D models and textures, the tools and loaders you'll need within Three.js to bring them to life, and best practices for managing these assets in your projects. This will unlock the ability to create a vast range of experiences, from importing detailed architectural visualizations to populating your scenes with characters and props.
graph LR; A[Your 3D Model (e.g., .gltf, .obj)] --> B(Three.js Loader); B --> C{Scene}; A[Texture Image (e.g., .jpg, .png)] --> B; B --> D(Material); D --> C;
The process generally involves obtaining a 3D model file and a corresponding texture file (or files). These files are then loaded by a specific 'loader' in Three.js, which interprets the file format and creates the necessary Three.js objects. For models, this typically means creating a BufferGeometry and associated Mesh. For textures, it means creating a Texture object that can then be applied to a Material.
We'll break down the loading process into two main categories: loading 3D models and loading textures. While they are often used together, understanding each individually will make the process much clearer. Let's dive in!