Autodesk Forge：通过 fitToView() 聚焦对象后以编程方式缩小

Question

在 select 并使用 fitToView(objectIds, model) 关注一个对象之后，我想以编程方式而不是通过鼠标事件缩小相机。

我尝试了以下代码，它能够缩小，但 3D space 变形了。如果你知道如何正确缩小，请告诉我。

// select and isolate target object
let dbid = [1137]
viewer.impl.visibilityManager.isolate(dbid, viewer.model)
viewer.select(dbid)

//focus on target object
viewer.getAggregateSelection((data) => {
    let rootId = data.selector.getInstanceTree().nodeAccess.rootId
    viewer.fitToView(rootId, viewer.model)
})

//zoom out camera
let cam = viewer.getCamera().perspectiveCamera
cam.zoom *= 0.05
viewer.impl.syncCamera();

Answer 1

您需要更改的不是变焦属性，而是相机位置：

var nav = viewer.navigation

var pos = nav.getPosition()

var target = nav.getTarget()

var viewdir = new THREE.Vector3()

viewdir.subVectors (pos, target).normalize()

// zooms out by 100 along the view direction
viewdir.multiplyScalar (100)

pos.add(viewdir)

nav.setPosition(pos)

Answer 2

   It's not the zoom property that you need to change but set the camera position: 
    let camera = this.viewer3D.getCamera();
    viewer.fitToView(dbIds, null, true); //provide your device id to locate
    var direction = new THREE.Vector3();
    camera.getWorldDirection( direction );
    //set distance move the camera forward to your needs (gives value in minus for zoomout)
    camera.position.add( direction.multiplyScalar(-15)); 
    let fov = viewer.navigation.getVerticalFov();  //or horizontalFov
    viewer.navigation.setRequestTransition(true, 
    camera.position,viewer.navigation.getTarget(), fov); //if not work then try fov + 20,30,40 etc..

Autodesk Forge：通过 fitToView() 聚焦对象后以编程方式缩小

Autodesk Forge: programmatically zoom out after focus on object by fitToView()

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