Files
mrp-qrcode/components/StepViewer.tsx
T
jason 76308b8aa3
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stage 8-step viewer
2026-04-21 13:26:48 -05:00

372 lines
13 KiB
TypeScript

"use client";
// In-browser STEP viewer. Uses `occt-import-js` (OpenCascade compiled to
// WASM) to triangulate STEP/STP into mesh buffers, then renders them with
// three.js and an OrbitControls camera.
//
// The WASM blob is served from /vendor/occt-import-js.wasm — copied there
// by scripts/copy-viewer-assets.mjs during predev/prebuild.
//
// This component is strictly client-side: both `three` and `occt-import-js`
// reach for `window`/`WebGL`, so we never import them at module top-level in
// server components. All imports inside here are fine because the file is
// marked "use client" and only ever mounted below a client boundary.
import { useEffect, useRef, useState } from "react";
interface Props {
/** Fully qualified URL that returns the STEP bytes (e.g. /api/v1/files/:id/download). */
url: string;
/** Optional class name for the outer wrapper. */
className?: string;
/** Show mesh edges for readability. Defaults to true. Disable on very complex assemblies. */
showEdges?: boolean;
}
type ViewerState =
| { kind: "idle" }
| { kind: "loading"; message: string }
| { kind: "ready"; triangleCount: number; meshCount: number }
| { kind: "error"; message: string };
export default function StepViewer({ url, className, showEdges = true }: Props) {
const containerRef = useRef<HTMLDivElement | null>(null);
const [state, setState] = useState<ViewerState>({ kind: "idle" });
useEffect(() => {
const hostNullable = containerRef.current;
if (!hostNullable) return;
// Capture in a non-nullable local so the async closure below retains the
// narrowing (TS flow analysis doesn't carry narrowing across async fns).
const host: HTMLDivElement = hostNullable;
let cancelled = false;
let cleanup: (() => void) | null = null;
async function run() {
setState({ kind: "loading", message: "Initialising viewer…" });
try {
// Dynamically import the heavy bits — keeps initial JS small and
// means nothing in here ever runs on the server.
const [{ default: occtFactory }, THREE, { OrbitControls }] =
await Promise.all([
import("occt-import-js"),
import("three"),
import("three/examples/jsm/controls/OrbitControls.js"),
]);
if (cancelled) return;
setState({ kind: "loading", message: "Fetching model…" });
const response = await fetch(url, { cache: "force-cache" });
if (!response.ok) {
throw new Error(`Download failed (${response.status})`);
}
const arrayBuffer = await response.arrayBuffer();
if (cancelled) return;
setState({ kind: "loading", message: "Parsing STEP file…" });
const occt = await occtFactory({
locateFile: (file) => `/vendor/${file}`,
});
if (cancelled) return;
const fileBuffer = new Uint8Array(arrayBuffer);
const result = occt.ReadStepFile(fileBuffer, null);
if (!result.success || result.meshes.length === 0) {
throw new Error(
result.success
? "No geometry found in this STEP file."
: "OpenCascade could not parse this STEP file.",
);
}
if (cancelled) return;
setState({ kind: "loading", message: "Building scene…" });
// --- three.js scene -----------------------------------------------
const width = host.clientWidth || 600;
const height = host.clientHeight || 400;
const renderer = new THREE.WebGLRenderer({ antialias: true, alpha: false });
renderer.setPixelRatio(window.devicePixelRatio || 1);
renderer.setSize(width, height, false);
renderer.setClearColor(0xf8fafc); // slate-50
host.appendChild(renderer.domElement);
renderer.domElement.style.display = "block";
renderer.domElement.style.width = "100%";
renderer.domElement.style.height = "100%";
renderer.domElement.style.touchAction = "none";
const scene = new THREE.Scene();
const ambient = new THREE.AmbientLight(0xffffff, 0.55);
scene.add(ambient);
const key = new THREE.DirectionalLight(0xffffff, 0.9);
key.position.set(1, 1.5, 1);
scene.add(key);
const fill = new THREE.DirectionalLight(0xffffff, 0.35);
fill.position.set(-1, -0.5, -1);
scene.add(fill);
const group = new THREE.Group();
let totalTris = 0;
const disposables: Array<{ dispose: () => void }> = [];
for (const m of result.meshes) {
const built = buildMesh(THREE, m, showEdges);
if (!built) continue;
group.add(built.mesh);
if (built.edges) group.add(built.edges);
totalTris += built.triangleCount;
disposables.push(...built.disposables);
}
scene.add(group);
// Center and frame.
const bbox = new THREE.Box3().setFromObject(group);
const size = new THREE.Vector3();
const center = new THREE.Vector3();
bbox.getSize(size);
bbox.getCenter(center);
group.position.sub(center); // recentre at origin
const camera = new THREE.PerspectiveCamera(45, width / height, 0.01, 1e7);
const radius = Math.max(size.x, size.y, size.z, 1);
const dist = radius * 2.4;
camera.position.set(dist, dist * 0.8, dist);
camera.lookAt(0, 0, 0);
camera.near = radius / 1000;
camera.far = radius * 1000;
camera.updateProjectionMatrix();
const controls = new OrbitControls(camera, renderer.domElement);
controls.enableDamping = true;
controls.dampingFactor = 0.08;
controls.target.set(0, 0, 0);
controls.update();
// Render loop.
let rafId = 0;
const render = () => {
controls.update();
renderer.render(scene, camera);
rafId = requestAnimationFrame(render);
};
render();
// Resize.
const ro = new ResizeObserver(() => {
const w = host.clientWidth;
const h = host.clientHeight;
if (w === 0 || h === 0) return;
renderer.setSize(w, h, false);
camera.aspect = w / h;
camera.updateProjectionMatrix();
});
ro.observe(host);
cleanup = () => {
cancelAnimationFrame(rafId);
ro.disconnect();
controls.dispose();
for (const d of disposables) {
try {
d.dispose();
} catch {
/* ignore */
}
}
renderer.dispose();
if (renderer.domElement.parentNode === host) {
host.removeChild(renderer.domElement);
}
};
if (cancelled) {
cleanup();
cleanup = null;
return;
}
setState({
kind: "ready",
triangleCount: totalTris,
meshCount: result.meshes.length,
});
} catch (err) {
if (cancelled) return;
const message = err instanceof Error ? err.message : "Unknown viewer error";
setState({ kind: "error", message });
}
}
run();
return () => {
cancelled = true;
if (cleanup) cleanup();
};
// Reload whenever the target file changes.
}, [url, showEdges]);
return (
<div className={className ?? "relative w-full h-[480px] rounded-lg border border-slate-200 bg-slate-50 overflow-hidden"}>
<div ref={containerRef} className="absolute inset-0" />
{state.kind !== "ready" ? (
<div className="pointer-events-none absolute inset-0 flex items-center justify-center">
<div className="rounded-md bg-white/80 backdrop-blur px-3 py-2 text-sm text-slate-600 border border-slate-200">
{state.kind === "error" ? (
<span className="text-red-600">Viewer error: {state.message}</span>
) : state.kind === "loading" ? (
<span>{state.message}</span>
) : (
<span>Preparing viewer</span>
)}
</div>
</div>
) : (
<div className="absolute bottom-2 right-2 rounded-md bg-white/80 backdrop-blur px-2 py-1 text-xs text-slate-500 border border-slate-200 pointer-events-none">
{state.meshCount} mesh{state.meshCount === 1 ? "" : "es"} · {state.triangleCount.toLocaleString()} tris
</div>
)}
</div>
);
}
// --------------------------------------------------------------------------
import type * as THREENS from "three";
import type { OcctMesh } from "occt-import-js";
interface BuiltMesh {
mesh: THREENS.Mesh;
edges: THREENS.Group | null;
triangleCount: number;
disposables: Array<{ dispose: () => void }>;
}
/**
* Adapted from occt-import-js/examples/three_viewer.html. Handles the
* per-BRep-face colouring scheme OCCT emits: a single indexed buffer
* geometry with one material per face group.
*/
function buildMesh(
THREE: typeof THREENS,
source: OcctMesh,
showEdges: boolean,
): BuiltMesh | null {
const positionArr = source.attributes.position?.array;
const indexArr = source.index?.array;
if (!positionArr || !indexArr || positionArr.length === 0 || indexArr.length === 0) {
return null;
}
const geometry = new THREE.BufferGeometry();
geometry.setAttribute(
"position",
new THREE.Float32BufferAttribute(
positionArr instanceof Float32Array ? positionArr : Float32Array.from(positionArr as ArrayLike<number>),
3,
),
);
if (source.attributes.normal?.array) {
const normalArr = source.attributes.normal.array;
geometry.setAttribute(
"normal",
new THREE.Float32BufferAttribute(
normalArr instanceof Float32Array ? normalArr : Float32Array.from(normalArr as ArrayLike<number>),
3,
),
);
} else {
// Fall back to computed normals if the importer didn't supply any.
}
geometry.name = source.name ?? "occt-mesh";
const indexTyped =
indexArr instanceof Uint32Array ? indexArr : Uint32Array.from(indexArr as ArrayLike<number>);
geometry.setIndex(new THREE.BufferAttribute(indexTyped, 1));
if (!source.attributes.normal?.array) {
geometry.computeVertexNormals();
}
const disposables: Array<{ dispose: () => void }> = [geometry];
const defaultColor = source.color
? new THREE.Color(source.color[0], source.color[1], source.color[2])
: new THREE.Color(0xb0b8c1); // slate-400-ish
const defaultMaterial = new THREE.MeshPhongMaterial({
color: defaultColor,
specular: 0x101010,
shininess: 30,
flatShading: false,
});
disposables.push(defaultMaterial);
const materials: THREENS.Material[] = [defaultMaterial];
const outlineMaterial = new THREE.LineBasicMaterial({ color: 0x334155 });
disposables.push(outlineMaterial);
const edges = showEdges ? new THREE.Group() : null;
const triangleCount = indexTyped.length / 3;
if (source.brep_faces && source.brep_faces.length > 0) {
for (const face of source.brep_faces) {
const c = face.color
? new THREE.Color(face.color[0], face.color[1], face.color[2])
: defaultMaterial.color;
const mat = new THREE.MeshPhongMaterial({ color: c, specular: 0x101010, shininess: 30 });
materials.push(mat);
disposables.push(mat);
}
let triangleIndex = 0;
let faceGroupIndex = 0;
while (triangleIndex < triangleCount) {
const firstIndex = triangleIndex;
let lastIndex: number;
let materialIndex: number;
if (faceGroupIndex >= source.brep_faces.length) {
lastIndex = triangleCount;
materialIndex = 0;
} else if (triangleIndex < source.brep_faces[faceGroupIndex].first) {
lastIndex = source.brep_faces[faceGroupIndex].first;
materialIndex = 0;
} else {
lastIndex = source.brep_faces[faceGroupIndex].last + 1;
materialIndex = faceGroupIndex + 1;
faceGroupIndex++;
}
geometry.addGroup(firstIndex * 3, (lastIndex - firstIndex) * 3, materialIndex);
if (edges) {
const inner = new THREE.BufferGeometry();
inner.setAttribute("position", geometry.attributes.position);
if (geometry.attributes.normal) {
inner.setAttribute("normal", geometry.attributes.normal);
}
inner.setIndex(new THREE.BufferAttribute(indexTyped.slice(firstIndex * 3, lastIndex * 3), 1));
const edgesGeom = new THREE.EdgesGeometry(inner, 30);
edges.add(new THREE.LineSegments(edgesGeom, outlineMaterial));
disposables.push(inner, edgesGeom);
}
triangleIndex = lastIndex;
}
} else if (edges) {
const edgesGeom = new THREE.EdgesGeometry(geometry, 30);
edges.add(new THREE.LineSegments(edgesGeom, outlineMaterial));
disposables.push(edgesGeom);
}
const mesh = new THREE.Mesh(
geometry,
materials.length > 1 ? materials : materials[0],
);
mesh.name = source.name ?? "occt-mesh";
if (edges) edges.renderOrder = mesh.renderOrder + 1;
return { mesh, edges, triangleCount, disposables };
}