Cesium restrictions camera into the underground

Sometimes when we Cesium operation, click the middle mouse wheel to change the angle of view, and sometimes make camera into the ground, resulting in very poor experience, the Internet, said a lot of the method, the results are not good, or no effect, the following is my turn to find the source code The method, effective pro-test. If you have questions may contact the author in accordance with the contact details on the column!

function limitCameraToGround(isOpen) {
        if (limitCameraHandler) {
            limitCameraHandler();
            limitCameraHandler = null;
        }
……

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Cesium restrictions camera into the underground

Article provides source code, are interested in this column, you can focus on a wave