Ask for help about ClippingPlane useage

I change a example from cesium sandcastle.
the codes is below

the codes i change is markered “//i change this code line”

my Questions is:
i change clippingPlane to vertical
but the clipping effect of 3dTiles with “point cloud” type
is not right with clipping plane.

the image above shows the wrong effect.
i think i shound give a right value to “clippingPlanes.modelMatrix”
but i don’t know how to do it.

Refer this samples

i study your codes
but,the examples about clip in your project have the limits below

const transformCenter = Cesium.Matrix4.getTranslation(
    new Cesium.Cartesian3()
if(!Cartesian3.equals(transformCenter, Cartesian3.ZERO)){
    // non georeference
    throw new Error("error");

but the 3dTiles data’s transformCenter in my codes don’t equal Cartesian3.ZERO
the 3dTiles data in my codes is

const pointCloudUrl = Cesium.IonResource.fromAssetId(16421);