Examples on Profile Relations

The image below shows an example of a profile defined by two sets of two relations:

The user entered a parallel and a vertical distance of 100 mm when defining the first relation to the hull, and the third relation to the plate in section respectively. Note that the entire contour of the plate in section is intersected with the plate with the profile, thus creating a rectangle serving as the relation.

This is also visible below, where a profile in bulb view is used for creating a profile with only one relation per end:

The first relation is a so called point relation. That is, the point of the contour of the indicated part that is closest to the indicated point will be used as the relation. The second relation is a minimal relation. This means that the point of the contour of the indicated part that is closest to the other end of the profile to be created will serve as the relation.  If distances are specified, they are interpreted in the direction of the line through the two points defined above.

Another possibility for defining a profile end by just one relation is by means of an angle from the horizontal line through one end of the profile towards a relation. For example:

Relations 1 and 2 define one end. From this point, a line is drawn making an angle of 60 degrees with a horizontal line (with respect to the drawing). This line intersects the third relation defining the other end.

It is also possible to describe a point by three relations.  In that case one relation is intersected by two others (intersections A and B) defining a contour with a certain length. On this contour a point can be defined by specifying a distance from point A. This distance can be either measured along the contour, or along a straight line through points A and B. In the latter case, a line is drawn through the other end of the profile and through the point on the straight line from A to B. This line is then intersected with the contour between A and B resulting in the desired point on the contour.

In the example above, the lower profile end is defined on 20% of the contour length between A and B. So the lower end of the profile is described by three relations and the top end by two relations. Relations 1,2 and 3 we call "partial" relations. The relations from which the distance is calculated we call the first partial relation, the relation to which the distance is being calculated is called the second partial relation. Finally, the relation along which the distance is to be measured is called the third partial relation.