# what is exact function of ratio coupling in catia?

ratio coupling used in multisection solid formation is necessary what is it and what happens if i dont do it???? similarly what all these other couplings do??

### 1 Answer

coupling allows you to select how the transition is mapped b/w the profiles

ratio- maps the profile together by curvature ratio

tangency- maps the profile together by their tangent discontinuity points.if there are not the same number of points in each curve then this option will fail.

tangency then curvature- maps the profile together by their curvature discontinuity points.as with tangency this option will fail if there are not the same number of points in each curve

vertices-maps the vertices of the profile.again there must be same number of vertices on each profile for this option to work