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Get your first result

Use this sample track-light file before trying your own photometry. It comes from the three.js examples; see fixture attribution and licenses.

Inspect and chart a file​

Install Node.js 22 or later, then run these commands in a new directory:

npm install -g @ies-tools/cli
curl -fL https://ies-tools.ben3d.ca/lights/track-light.ies -o track-light.ies
ies inspect track-light.ies
ies validate track-light.ies --strict
ies chart track-light.ies -o polar.svg

inspect prints the file's manufacturer, luminaire, flux and beam estimates. validate exits successfully for this sample. Open polar.svg to see its principal-plane intensity curves. These commands need no GPU. Outputs are never overwritten: choose another output name when repeating an export.

For a 3D preview, run ies view track-light.ies --open in a hardware-WebGL2-capable browser. Drag to orbit, switch chart tabs, and press Ctrl+C in the terminal to stop the server. The file is processed locally.

Next: CLI guide, export charts, or validate files in CI.

Parse a file in Node​

In the directory containing track-light.ies:

npm install @ies-tools/core

Save this as inspect.mjs, then run node inspect.mjs:

import { readFile } from 'node:fs/promises';
import { parsePhotometry, sampleIntensity, calculateLuminousFlux } from '@ies-tools/core';

const text = await readFile('track-light.ies', 'utf8');
const document = parsePhotometry(text);
console.log('Nadir intensity (cd):', sampleIntensity(document.profile, 0, 0));
console.log('Integrated output (lm):', calculateLuminousFlux(document.profile));

Both values should be finite and positive. parsePhotometry detects IES or EULUMDAT from the text. Invalid input throws an error; for diagnostics instead, use structured validation. No Three.js, React or GPU is required.

Next: core guide and conversion with loss warnings.

Show the sample in React​

In an existing client-rendered React 19 app:

npm install @ies-tools/viewer @ies-tools/core three@^0.186.0

Download the sample above into public/lights/track-light.ies. Render this component:

import { LightViewer } from '@ies-tools/viewer/react';
import '@ies-tools/viewer/styles.css';

export default function App() {
  return (
    <LightViewer
      src="/lights/track-light.ies"
      style={{ height: 480 }}
      onError={(error) => console.error(error.message)}
    />
  );
}

Start your app's development server. You should see a narrow beam illuminating the floor and wall; drag to orbit. The stylesheet supplies the settings UI. The 3D view requires hardware WebGL2 and a browser DOM; with server rendering, mount it on the client.

Next: React charts and local file input, plain HTML integration, or troubleshooting.

Prefer an editor? Install the VS Code extension and open the sample file.