Get mouse x,y,z coordinates depending on camera rotation

Hi I’m trying to get the delta movement of my mouse in a 3d scene in every axis depending on cameras rotation without using Raycasting. Could anyone point me in a correct direction.
Im able to get a 2d delta translation but im not sure on how to apply cameras rotation to know which axis apply it to. (x,y | z,x etc).

_getMousePositionInScene(mousePos) {
        let vector = new Vector3(mousePos.x, mousePos.y, 0);
        let dir = vector.sub(;
        let distance = - / dir.z;
        let pos =;
        return pos;

Thanks in advance