   Using Nvidia's SDK effects?
  I'm trying to use the halo effect.  I've loaded it and have the following code to impliment it for a leaf that I'm drawing.  But nothing happens except the system slows in performance...[source lang=c#]  this.device.SetTexture(0, this.GetSurfaceTexture("white").texture);  Microsoft.DirectX.Direct3D.Effect effect = this.GetSurfaceEffect("halo").effect;  effect.Technique = "Main";  int passes = effect.Begin(0);  for (int i = 0; i < passes; i++)  { effect.BeginPass(i); this.GetSurfaceMesh("leaf01").mesh.DrawSubset(0); effect.EndPass();  }  effect.End();  this.device.SetTexture(0, this.GetSurfaceTexture("white").texture);  this.GetSurfaceMesh("leaf01").mesh.DrawSubset(0);Any help is much appreciated,-Devin[/source]   
  Perhaps there is a book or article that explains the semantics and such for HLSL fx files?   