Wie kann man die Richtung der Textur im Objekt CylinderGeometry umkehren?

Question

Wie umkehren Sie die Richtung der Anwendung der Textur im Objekt CylinderGeometry?

var obj = new THREE.Mesh(
    new THREE.CylinderGeometry(20, 15, 1, 20), 
    new THREE.MeshLambertMaterial({color: 0x000000}) //the material is later changed to the correct 
); 

Vielen Dank im Voraus für Ihre Hilfe :)

Answer 1

Diese Funktion:

 var invertTextureOnCylinderGeometry = function(obj) { 
      var faceVertexes = obj.geometry.faceVertexUvs[0]; 
      var faceVertexesLength = faceVertexes.length; 
      var divisionT = 1/(faceVertexesLength * 0.25); 
      faceVertexes.map(function(face, index) { 
       if (index < 0.5*faceVertexesLength) { 
        var thisIndexDivision = [ 
         Math.floor(index/2) * divisionT, 
         Math.ceil((index+divisionT)/2) * divisionT 
        ]; 
        if (index % 2) { 
         face[0].set(1, thisIndexDivision[0]); 
         face[1].set(1, thisIndexDivision[1]); 
         face[2].set(0, thisIndexDivision[1]); 
        } else { 
         face[0].set(0, thisIndexDivision[0]); 
         face[1].set(1, thisIndexDivision[0]); 
         face[2].set(0, thisIndexDivision[1]); 
        } 
       } 
      }); 
      obj.geometry.uvsNeedUpdate = true; 
     };