HI....I know catia surface modelling but i have one dought.....wat is mean by closed point......for example i made in juck.am using multi section surface...but am not make a top body..then changing the closing point i make a currect object...y we changing the closed point thats my dought
first example: you are trying to make solid between 2x polygon section. lets say it both are hexagon but one is smaller than the other. if you want to couple vertex to each other you must use "vertices".
second example: one of your section is circle and the other one is square. circle has one start point but square has 4x vertex. if you select ratio, catia will divide perimeter of circle 4. and you will couple they automatically.