Colorize a point cloud with various modes (native colors, color layer, elevation gradient...).

Options
Mode
Color ramp
100% © IGN

Point clouds can be colorized from different methods : using the original color in the point cloud, coloring using an elevation gradient, or coloring using an external image source, such as a WMS layer.

index.js
import colormap from 'colormap';

import { Color, MathUtils, Vector3 } from 'three';
import { MapControls } from 'three/examples/jsm/controls/MapControls.js';

import Instance from '@giro3d/giro3d/core/Instance.js';
import Tiles3D from '@giro3d/giro3d/entities/Tiles3D.js';
import ColorLayer from '@giro3d/giro3d/core/layer/ColorLayer.js';
import PointCloudMaterial, { MODE } from '@giro3d/giro3d/renderer/PointCloudMaterial.js';
import Tiles3DSource from '@giro3d/giro3d/sources/Tiles3DSource.js';
import WmsSource from '@giro3d/giro3d/sources/WmsSource.js';
import Inspector from '@giro3d/giro3d/gui/Inspector.js';
import Extent from '@giro3d/giro3d/core/geographic/Extent.js';

function makeColorRamp(preset, nshades) {
    const values = colormap({ colormap: preset, nshades });
    const colors = values.map(v => new Color(v));

    return colors;
}

const colorRamps = {};

function makeColorRamps() {
    const nshades = 256;

    colorRamps.viridis = makeColorRamp('viridis', nshades);
    colorRamps.jet = makeColorRamp('jet', nshades);
    colorRamps.blackbody = makeColorRamp('blackbody', nshades);
    colorRamps.earth = makeColorRamp('earth', nshades);
    colorRamps.bathymetry = makeColorRamp('bathymetry', nshades);
    colorRamps.magma = makeColorRamp('magma', nshades);
    colorRamps.par = makeColorRamp('par', nshades);

    colorRamps.slope = makeColorRamp('RdBu', nshades);
}

makeColorRamps();

const tmpVec3 = new Vector3();

Instance.registerCRS(
    'EPSG:3946',
    '+proj=lcc +lat_1=45.25 +lat_2=46.75 +lat_0=46 +lon_0=3 +x_0=1700000 ' +
        '+y_0=5200000 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs',
);

const viewerDiv = document.getElementById('viewerDiv');

const instance = new Instance(viewerDiv, {
    crs: 'EPSG:3946',
    renderer: {
        clearColor: 0xcccccc,
    },
});

// Create a custom material for our point cloud.
const material = new PointCloudMaterial({
    size: 4,
    mode: MODE.TEXTURE,
});

material.colorMap.min = 100;
material.colorMap.max = 600;
material.colorMap.colors = colorRamps['viridis'];

// Create the 3D tiles entity
const pointcloud = new Tiles3D(
    'pointcloud',
    new Tiles3DSource('https://3d.oslandia.com/3dtiles/lyon.3dtiles/tileset.json'),
    {
        material,
    },
);

let colorLayer;

function placeCamera(position, lookAt) {
    instance.camera.camera3D.position.set(position.x, position.y, position.z);
    instance.camera.camera3D.lookAt(lookAt);
    // create controls
    const controls = new MapControls(instance.camera.camera3D, instance.domElement);
    controls.target.copy(lookAt);
    controls.enableDamping = true;
    controls.dampingFactor = 0.25;

    instance.useTHREEControls(controls);

    instance.notifyChange(instance.camera.camera3D);
}

// add pointcloud to scene
function initializeCamera() {
    const bbox = pointcloud.root.bbox
        ? pointcloud.root.bbox
        : pointcloud.root.boundingVolume.box.clone().applyMatrix4(pointcloud.root.matrixWorld);

    instance.camera.camera3D.far = 2.0 * bbox.getSize(tmpVec3).length();

    const ratio = bbox.getSize(tmpVec3).x / bbox.getSize(tmpVec3).z;
    const position = bbox.min
        .clone()
        .add(bbox.getSize(tmpVec3).multiply({ x: 0, y: 0, z: ratio * 0.5 }));
    const lookAt = bbox.getCenter(tmpVec3);
    lookAt.z = bbox.min.z;

    const extent = Extent.fromBox3('EPSG:3946', bbox);

    placeCamera(position, lookAt);

    const colorize = new WmsSource({
        url: 'https://data.geopf.fr/wms-r',
        projection: 'EPSG:3946',
        layer: 'HR.ORTHOIMAGERY.ORTHOPHOTOS',
        imageFormat: 'image/jpeg',
    });

    colorLayer = new ColorLayer({
        name: 'wms_imagery',
        extent,
        source: colorize,
    });

    pointcloud.attach(colorLayer);

    instance.renderingOptions.enableEDL = true;
    instance.renderingOptions.enableInpainting = true;
    instance.renderingOptions.enablePointCloudOcclusion = true;

}

instance.add(pointcloud).then(initializeCamera);

Inspector.attach(document.getElementById('panelDiv'), instance);
instance.domElement.addEventListener('dblclick', e =>
    console.log(
        instance.pickObjectsAt(e, {
            // Specify a radius around where we click so we don't have to precisely be on a point
            // to select it
            radius: 5,
            // Limit the number of results for better performances
            limit: 10,
            // Some points are incoherent in the pointcloud, don't pick them
            filter: p => !Number.isNaN(p.point.z) && p.point.z < 1000,
        }),
    ),
);

instance.notifyChange();

function bindSlider(name, fn) {
    const slider = document.getElementById(name);
    slider.oninput = function oninput() {
        fn(slider.value);
        instance.notifyChange();
    };
}

function bindToggle(name, action) {
    const toggle = document.getElementById(name);
    toggle.oninput = () => {
        const state = toggle.checked;
        action(state);
        instance.notifyChange();
    };
}

bindToggle('edl-enable', v => {
    instance.renderingOptions.enableEDL = v;
});
bindToggle('occlusion-enable', v => {
    instance.renderingOptions.enablePointCloudOcclusion = v;
});
bindToggle('inpainting-enable', v => {
    instance.renderingOptions.enableInpainting = v;
});
bindSlider('edl-radius', v => {
    instance.renderingOptions.EDLRadius = v;
});
bindSlider('edl-intensity', v => {
    instance.renderingOptions.EDLStrength = v;
});
bindSlider('inpainting-steps', v => {
    instance.renderingOptions.inpaintingSteps = v;
});
bindSlider('opacity', v => {
    pointcloud.opacity = v;
    document.getElementById('opacityLabel').innerText =
        `Point cloud opacity: ${Math.round(v * 100)}%`;
});

function bindColorMapBounds(callback) {
    /** @type {HTMLInputElement} */
    const lower = document.getElementById('min');

    /** @type {HTMLInputElement} */
    const upper = document.getElementById('max');

    callback(lower.valueAsNumber, upper.valueAsNumber);

    function updateLabels() {
        document.getElementById('minLabel').innerText =
            `Lower bound: ${Math.round(lower.valueAsNumber)}m`;
        document.getElementById('maxLabel').innerText =
            `Upper bound: ${Math.round(upper.valueAsNumber)}m`;
    }

    lower.oninput = function oninput() {
        const rawValue = lower.valueAsNumber;
        const clampedValue = MathUtils.clamp(rawValue, lower.min, upper.valueAsNumber - 1);
        lower.valueAsNumber = clampedValue;
        callback(lower.valueAsNumber, upper.valueAsNumber);
        instance.notifyChange();
        updateLabels();
    };

    upper.oninput = function oninput() {
        const rawValue = upper.valueAsNumber;
        const clampedValue = MathUtils.clamp(rawValue, lower.valueAsNumber + 1, upper.max);
        upper.valueAsNumber = clampedValue;
        callback(lower.valueAsNumber, upper.valueAsNumber);
        instance.notifyChange();
        updateLabels();
    };
}

bindColorMapBounds((min, max) => {
    material.colorMap.min = min;
    material.colorMap.max = max;
});

const colorMapGroup = document.getElementById('colormapGroup');

document.getElementById('pointcloud_mode').addEventListener('change', e => {
    const newMode = parseInt(e.target.value, 10);
    material.mode = newMode;

    if (newMode === MODE.ELEVATION) {
        colorMapGroup.classList.remove('d-none');
    } else {
        colorMapGroup.classList.add('d-none');
    }

    instance.notifyChange(pointcloud, true);
    if (colorLayer) {
        colorLayer.visible = newMode === MODE.TEXTURE;
        instance.notifyChange(colorLayer, true);
    }
});

document.getElementById('colormap').addEventListener('change', e => {
    const newRamp = e.target.value;
    material.colorMap.colors = colorRamps[newRamp];
    instance.notifyChange(pointcloud, true);
});
index.html
<!doctype html>
<html lang="en">
    <head>
        <title>Colorized 3D Tiles Point Cloud</title>
        <meta charset="UTF-8" />
        <meta name="name" content="colorized_pointcloud" />
        <meta name="description" content="Colorize a point cloud with various modes (native colors, color layer, elevation gradient...)." />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />

        <link rel="icon" href="https://giro3d.org/images/favicon.svg" />
        <link href="https://giro3d.org/assets/bootstrap-custom.css" rel="stylesheet" />
        <script src="https://giro3d.org/assets/bootstrap.bundle.min.js"></script>
        <link
            rel="stylesheet"
            type="text/css"
            href="https://giro3d.org/latest/css/example.css"
        />

        
    </head>

    <body>
        <div id="viewerDiv" class="m-0 p-0 w-100 h-100"></div>
        <div id="panelDiv" class="position-absolute top-0 start-0 mh-100 overflow-auto"></div>

        <div class="side-pane-with-status-bar">
            <!-- Top color layer -->
            <div class="card">
                <div class="card-header">Options</div>

                <div class="card-body" id="top-options">
                    <!-- Coloring mode -->
                    <div class="input-group">
                        <span class="input-group-text flex-grow-1">Mode</span>
                        <select
                            class="btn btn-outline-primary btn-sm"
                            id="pointcloud_mode"
                            autocomplete="off"
                        >
                            <option value="0">point cloud colors</option>
                            <option value="5">elevation gradient</option>
                            <option value="4" selected>color layer</option>
                        </select>
                    </div>

                    <!-- Color ramp -->
                    <div class="d-none my-2" id="colormapGroup">
                        <div class="input-group">
                            <span class="input-group-text flex-grow-1">Color ramp</span>
                            <select class="btn btn-outline-primary btn-sm" id="colormap" autocomplete="off">
                                <option value="viridis" selected>Viridis</option>
                                <option value="jet">Jet</option>
                                <option value="blackbody">Blackbody</option>
                                <option value="earth">Earth</option>
                                <option value="bathymetry">Bathymetry</option>
                                <option value="magma">Magma</option>
                                <option value="par">Par</option>
                            </select>
                        </div>

                        <div class="input-group my-2">
                            <label for="min" class="form-label" id="minLabel">Lower bound: 100m</label>
                            <div class="input-group">
                                <input
                                    type="range"
                                    min="0"
                                    max="1000"
                                    value="100"
                                    class="form-range"
                                    id="min"
                                    autocomplete="off"
                                />
                            </div>
                        </div>

                        <div class="input-group my-2">
                            <label for="max" class="form-label" id="maxLabel">Upper bound: 600m</label>
                            <div class="input-group">
                                <input
                                    type="range"
                                    min="0"
                                    max="1000"
                                    value="600"
                                    class="form-range"
                                    id="max"
                                    autocomplete="off"
                                />
                            </div>
                        </div>
                    </div>

                    <!-- Opacity -->
                    <div class="input-group my-2">
                        <label for="opacity" class="form-label" id="opacityLabel"
                            >Point cloud opacity: 100%</label
                        >
                        <div class="input-group">
                            <input
                                type="range"
                                min="0"
                                max="1"
                                step="0.05"
                                value="1"
                                class="form-range"
                                id="opacity"
                                autocomplete="off"
                            />
                        </div>
                    </div>

                    <!-- Activate EDL -->
                    <div class="input-group my-2">
                        <div>
                            <div class="form-check form-switch">
                                <input
                                    class="form-check-input"
                                    checked
                                    type="checkbox"
                                    role="switch"
                                    id="edl-enable"
                                    autocomplete="off"
                                />
                                <label class="form-check-label" for="edl-enable"
                                    >Eye dome lighting (EDL)</label
                                >
                            </div>
                        </div>
                    </div>

                    <!-- EDL intensity -->
                    <div class="input-group my-2">
                        <label for="edl-intensity" class="form-label">EDL intensity</label>
                        <div class="input-group">
                            <input
                                type="range"
                                min="0"
                                step="0.05"
                                max="2"
                                value="0.7"
                                class="form-range"
                                id="edl-intensity"
                                autocomplete="off"
                            />
                        </div>
                    </div>

                    <!-- EDL radius -->
                    <div class="input-group my-2">
                        <label for="edl-radius" class="form-label">EDL radius</label>
                        <div class="input-group">
                            <input
                                type="range"
                                min="0.1"
                                step="0.05"
                                max="5"
                                value="1.5"
                                class="form-range"
                                id="edl-radius"
                                autocomplete="off"
                            />
                        </div>
                    </div>

                    <!-- Activate occlusion -->
                    <div class="input-group my-2">
                        <div>
                            <div class="form-check form-switch">
                                <input
                                    class="form-check-input"
                                    checked
                                    type="checkbox"
                                    role="switch"
                                    id="occlusion-enable"
                                    autocomplete="off"
                                />
                                <label class="form-check-label" for="occlusion-enable"
                                    >Point occlusion effect</label
                                >
                            </div>
                        </div>
                    </div>

                    <!-- Activate inpainting -->
                    <div class="input-group my-2">
                        <div>
                            <div class="form-check form-switch">
                                <input
                                    class="form-check-input"
                                    checked
                                    type="checkbox"
                                    role="switch"
                                    id="inpainting-enable"
                                    autocomplete="off"
                                />
                                <label class="form-check-label" for="inpainting-enable">Inpainting</label>
                            </div>
                        </div>
                    </div>

                    <!-- Inpainting steps -->
                    <div class="input-group my-2">
                        <label for="inpainting-steps" class="form-label">Inpainting steps</label>
                        <div class="input-group">
                            <input
                                type="range"
                                min="1"
                                step="1"
                                max="10"
                                value="2"
                                class="form-range"
                                id="inpainting-steps"
                                autocomplete="off"
                            />
                        </div>
                    </div>
                </div>
            </div>
        </div>

        <script type="module" src="index.js"></script>
        <script>
            /* activate popovers */
            const popoverTriggerList = [].slice.call(
                document.querySelectorAll('[data-bs-toggle="popover"]'),
            );
            popoverTriggerList.map(
                // bootstrap is used as script in the template, disable warning about undef
                // eslint-disable-next-line no-undef
                popoverTriggerEl =>
                    new bootstrap.Popover(popoverTriggerEl, {
                        trigger: 'hover',
                        placement: 'left',
                        content: document.getElementById(
                            popoverTriggerEl.getAttribute('data-bs-content'),
                        ).innerHTML,
                        html: true,
                    }),
            );
        </script>
    </body>
</html>
package.json
{
    "name": "colorized_pointcloud",
    "dependencies": {
        "colormap": "^2.3.2",
        "@giro3d/giro3d": "0.37.2"
    },
    "devDependencies": {
        "vite": "^3.2.3"
    },
    "scripts": {
        "start": "vite",
        "build": "vite build"
    }
}