Dynamic Model Manipulation in Three.js

For your requirement of dynamically adjusting a GLTF model by selecting and moving points, Three.js offers several approaches, particularly through its addon libraries.

TransformControls

The most relevant tool for your needs would be TransformControls, which is part of the Three.js addons:

JAVASCRIPTCopied
import { TransformControls } from 'three/examples/jsm/controls/TransformControls.js';

// Create transform controls
const transformControls = new TransformControls(camera, renderer.domElement);
scene.add(transformControls);

// Attach to an object
transformControls.attach(yourObject);

// Set mode (translate, rotate, scale)
transformControls.setMode('translate'); // or 'scale', 'rotate'

DragControls

For more specific point-based manipulation, you might want to use DragControls:

JAVASCRIPTCopied
import { DragControls } from 'three/examples/jsm/controls/DragControls.js';

// Create an array of draggable objects (could be vertices or control points)
const dragObjects = [];

// Create drag controls
const dragControls = new DragControls(dragObjects, camera, renderer.domElement);

// Add event listeners
dragControls.addEventListener('dragstart', function (event) {
  // Handle drag start
});

dragControls.addEventListener('drag', function (event) {
  // Update model based on point movement
});

Advanced Approach

For more complex deformation where moving specific points affects the rest of the model:

1. You'll need to work with the model's geometry directly
2. Implement a deformation algorithm (like skeletal deformation or cage-based deformation)
3. Update the geometry's vertices based on control point movement

This would require:

1. Extracting the BufferGeometry from your GLTF model
2. Creating control points at key vertices
3. Implementing a deformation algorithm that updates all vertices based on control point movement

Additional Tools

You might also want to explore:

• BufferGeometryUtils from the Utils addons for geometry manipulation
• SkeletonUtils if your model has a skeleton that can be manipulated

For very complex deformations, you might need to supplement Three.js with specialized libraries for mesh deformation, but for most use cases, the built-in tools should be sufficient.