Adding Design Points

To provide convenient reference points for the relative positioning of items which make up the design template model, a design point can be created at any required location.

A design point, owned by a Design Pointset (DPSE), can be specified in three ways:

• A Cartesian Point (DPCA) is specified in terms of its coordinates only.

• A Cylindrical Point (DPCY) is specified as a position on the surface of a cylinder at a given position and with given dimensions.

• A Spherical Point (DPSP) is specified as a position on the surface of a sphere at a given position and with given dimensions.

Each design point, like a p-point, has both a position and an orientation. (The on-line help includes diagrams illustrating these concepts; refer to these if you need further clarification.)

For convenience when positioning the sub-equipments which will represent the ends of the vessel, we will create a design point at the center of each end of the vessel body.

Exercise continues:

1. Set the view direction to Look > East. Check that the Vessel Main Body template is the current element. Notice that this already owns an empty Design Pointset (DPSET 1). Select Modify > Points. You will see a Design Points form showing that no points have yet been defined.

2. From the Design Points menu bar, select Create > Cartesian Point. On the resulting form enter the following data:

   Number	1 (set automatically)
   Description	Datum Point 1
   Function	SUBE
   Point Direction
   Direction of Design Point (Z)	ZN
   Normal direction (Y)	YE

   (This orientation will not be relevant when positioning items relative to this design point, but is set here so that you will see the design point better in the 3D View.)

   We will position the design point by graphical picking. Click the Pick button, then pick P1 of CYLINDER 1 ....

   OK the Create - Cartesian Design Point form. Notice how the new point is shown in the list in the Design Points form and is also labelled (as DP1) in the 3D View. To change the colour of the displayed design point, if it is difficult to see, select Settings > Graphics > Colour and change the Aids colour.

3. Create a similar design point, Datum Point 2, at the other end of the vessel body. The Create Cartesian Design Point form will have retained the previous settings, so you only need edit these slightly. The new point should have its Z direction set to S and should be positioned at P2 of CYLINDER 1 ....

We will pause here to introduce two new concepts which are relevant at this stage of the exercise.