Custom scale for ImageMaterialProperty

Hey, everybody. I need to make smooth scaling for ImageMaterialProperty. Here is my code where I create Entity:

                                          let plane = new Entity({
                    position: position,
                    orientation: orientation,
                    properties: {
                        type: 'icon'
                    },
                    parent: airObj,
                    name: 'Icon',
                    plane: {
                        show: true,
                        plane: new Plane(Cartesian3.UNIT_Z, 0.0),
                        dimensions: new Cartesian2(30000.0, 30000.0),
                        material: new ImageMaterialProperty({
                            image: airs,
                            transparent: true,
                        }),
                                             }
                })

I have my custom one but it shakes the picture too much:

cesium.viewer.scene.preRender.addEventListener(function () { let cameraHeight = cesium.viewer.scene.camera.positionCartographic.height;


            // var newSize = 25000.0 * (cameraHeight / 2000000);
            // newSize = Math.max(newSize, 100.0);
            dataSource.entities.values.forEach((item) => {
                
                 if (cameraHeight > minHeight && cameraHeight < maxHeight)             item._children[0]._plane._dimensions.setValue(new Cartesian2(newSize, newSize));
                if (cameraHeight  > 1000000) {
                    item.model.show.setValue(false)
                    item._children[0].show = true;
                }else {
                    item._children[0].show = false
                    item.model.show.setValue(true);
                }
                
            })

        })

Thanks in advance for your advice and help!