hi guys, i am trying to move the curtains with wind but i need to know what is the best way to do that. i saved the vertics of the curtain in a vertex buffer and on each frame i change with the velocity of the wind on each vertex according to the Z axis (up direction) . but i am having a problem that is : i am saving the vertexs in an array of CustomVertex.PositionNormalTextured _verts and i am saving the changes when i apply the velocity to another CustomVertex.PositionNormalTextured _OutVerts then i send the data to my Vertex buffer using VB.setData( _OutVerts , 0 , 0 ) but the problem is that the _verts is also changing although i am not changing it !!!!!!!! can anybody tell me what might be the problem ?? and is there a better way to shake the curtains ??? thanks for any help, Best Regards, Jad Salloum

You could create a "vertex-sensitiveness-to-wind" variable and store it in each vertex, then move each vertex directly in a shader updating only a wind velocity variable in the shader. That way you would stay out from locknig amd unlocking your vertex buffer each frame.