Display Tangent, Normal, and Binormal of a Path3D

Displays a Path3D Curve

This snippet displays a Path3D curve and, at each point, its tangent, normal, and binormal in red, green, and blue respectively. The size parameter, which defaults to 0.5, sets the length of the tangents, normals, and binormals.

import { Color3 } from "@babylonjs/core/Maths/math.color";
import { MeshBuilder } from "@babylonjs/core/Meshes/meshBuilder";
function showPath3D(path3d, size) {
    size = size || 0.5;
    const curve = path3d.getCurve();
    const tgts = path3d.getTangents();
    const norms = path3d.getNormals();
    const binorms = path3d.getBinormals();
    let vcTgt, vcNorm, vcBinorm;
    const line = MeshBuilder.CreateLines("curve", { points: curve }, scene);
    for (let i = 0; i < curve.length; i++) {
        vcTgt = MeshBuilder.CreateLines("tgt" + i, { points: [curve[i], curve[i].add(tgts[i].scale(size))] }, scene);
        vcNorm = MeshBuilder.CreateLines("norm" + i, { points: [curve[i], curve[i].add(norms[i].scale(size))] }, scene);
        vcBinorm = MeshBuilder.CreateLines("binorm" + i, { points: [curve[i], curve[i].add(binorms[i].scale(size))] }, scene);
        vcTgt.color = Color3.Red();
        vcNorm.color = Color3.Green();
        vcBinorm.color = Color3.Blue();
    }
}

Playground

Display Path3D Info