A method for placing at least one object (On) on a surface, the type of object being a tile, brick, roof panel, wall panel or other surface layer material, the object being carried and positioned by a tool, the method comprising: determining a deviation in at least one dimension between a line of sight between a first and a second object placed on the surface, and an optical line directed from the first towards the second object, the optical line being generated by an optical source placed in the first object on the surface, the line of sight being a line connecting the first and a second objects and parallel to the surface determining a position (Xn, Zn) in at least one dimension for the tool based on the determined deviation, and positioning the tool so that the position (Xn, Zn) is achieved, thereby placing the object (On) on the surface, whereby the first and the second object are placed on the surface manually or by an automated process, characterised in that the first and second objects are the same type of object as the object (On) to be placed by the tool, and in that the step of determining the deviation comprises: determining a distance between the first and second objects along the line of sight, generating an optical line, determining a distance (XO, Z0) from at least an edge or a surface of the first object to the optical line, and determining a distance (X1, Z1) from at least a corresponding edge or a corresponding surface of the second object to the optical line, determining a distance (Yn), along the line of sight, from the first object to a position where the object (On) carried by the tool is to be placed, and determining the position (Xn, Zn) for the tool based at least on the distance between the first and second objects along the line of sight, the distance (XO, Z0) from at least an edge or a surface of the first object to the optical line, the distance (X1, Z1) from at least a corresponding edge or a corresponding surface of the second object to the optical line and the distance (Yn) from the first object to the object (On) to be placed. determining a deviation in at least one dimension between a line of sight between a first and a second object placed on the surface, and an optical line directed from the first towards the second object, the optical line being generated by an optical source placed in the first object on the surface, the line of sight being a line connecting the first and a second objects and parallel to the surface determining a position (Xn, Zn) in at least one dimension for the tool based on the determined deviation, and positioning the tool so that the position (Xn, Zn) is achieved, thereby placing the object (On) on the surface, whereby the first and the second object are placed on the surface manually or by an automated process, characterised in that the first and second objects are the same type of object as the object (On) to be placed by the tool, and in that the step of determining the deviation comprises: determining a distance between the first and second objects along the line of sight, generating an optical line, determining a distance (XO, Z0) from at least an edge or a surface of the first object to the optical line, and determining a distance (X1, Z1) from at least a corresponding edge or a corresponding surface of the second object to the optical line, determining a distance (Yn), along the line of sight, from the first object to a position where the object (On) carried by the tool is to be placed, and determining the position (Xn, Zn) for the tool based at least on the distance between the first and second objects along the line of sight, the distance (XO, Z0) from at least an edge or a surface of the first object to the optical line, the distance (X1, Z1) from at least a corresponding edge or a corresponding surface of the second object to the optical line and the distance (Yn) from the first object to the object (On) to be placed. determining a distance between the first and second objects along the line of sight, generating an optical line, determining a distance (XO, Z0) from at least an edge or a surface of the first object to the optical line, and determining a distance (X1, Z1) from at least a corresponding edge or a corresponding surface of the second object to the optical line, determining a distance (Yn), along the line of sight, from the first object to a position where the object (On) carried by the tool is to be placed, and determining the position (Xn, Zn) for the tool based at least on the distance between the first and second objects along the line of sight, the distance (XO, Z0) from at least an edge or a surface of the first object to the optical line, the distance (X1, Z1) from at least a corresponding edge or a corresponding surface of the second object to the optical line and the distance (Yn) from the first object to the object (On) to be placed.