With this material you can display the wireframe of the assignt model:
Code:
  
material mat_modelWire 
{
	effect = "
		DWORD wfcolor = 0xFFFEFFFF; 

		technique wireframe 
		{ 
			pass p0 
			{ 

				TextureFactor = <wfcolor>; 
				CullMode = None; 
				FillMode = Wireframe; 
				ColorOp[0] = SelectArg1; 
				ColorArg1[0] = TFactor; 
			} 
		}";
}