LCCObject::raycast

Screen-click-based raycasting.

Can be used for annotation, measurement, ground detection (digital humans), and more.

Version Requirement

SDK v0.3.0+

Engine Support

Three.js / CesiumJS

API

LCCObject::raycast(param: RaycastParam): IPoint3 | null

Parameters

Parameter	Type	Required	Default	Description
`param.evt`	`MouseEvent` / `PointerEvent`	Yes	-	Mouse click event, e.g., mousedown.
`param.maxDistance`	`number`	Yes	-	Maximum detection distance, in meters.
`param.radius`	`number`	Yes	-	Detection precision; adjust based on the actual scenario, in meters.
`param.opacityThreshold`	`number`	No	`0.5`	Opacity threshold for high-precision detection, range `[0, 1]`. Only effective when `usePrecisionRaycast` is `true`. SDK v0.6.3+

Return Value

IPoint3 | null — Detected point coordinates (x, y, z) in world space. Returns null if no point is detected.

Usage Example

Three.js

document.addEventListener('mousedown', (evt) => {
    let checkPos = lccObject.raycast({ evt: evt, maxDistance: 100, radius: 0.1 });
    if (checkPos) {
        console.log(checkPos.x, checkPos.y, checkPos.z);
    } else {
        // No point detected
    }
});

CesiumJS

viewer.scene.canvas.addEventListener('pointerdown', (evt) => {
    let checkPos = lccObject.raycast({ evt: evt, maxDistance: 100, radius: 0.1 });
    if (checkPos) {
        console.log(checkPos.x, checkPos.y, checkPos.z);
    } else {
        // No point detected
    }
});

Notes

This method must be called after the success callback of LCCRender.load() has been triggered.
In Cesium, listen to the canvas pointerdown event, not document's mousedown.
The returned coordinates are in world space.

LCCObject::raycastFromOrigin()
LCCObject::intersectsRayExt()