Ali Torabi

We use curve controller in PARA 3D to visualize the curvature of a spline object.

In first video you learn how to find the intersection of two coplanar lines. Notice that if two lines are not intersecting program will generates some error. in the second video we find the closest point on one line to a series of lines from another parametric array. Program automatically sets the controllers for point A and B. if two lines are actually intersection the closest point is equal to the intersection point. also you can find the apparent intersection of two lines on a plane. For example the apparent intersection on XY plane is the intersection of projected lines on this plane(intersection from top view) .

In this video you learn how to use the Material modifier to control the material of the objects inside the array.

Here is a short video explaining what type of objects you can use in surface controller.

we can summaries all as following:

1. NURBS objects with at least one surface inside. If surface is trimmed the based surface (surface before trimming) will be considered as target surface. if more than one surface exist in the object you can choose the surface from the drop down menu.
2. UVW mapping of any kind of object can also be the source of data in surface controller. for this the target object must have at least one UVW map channel. This option is not preferred  option but can be used for NURBS surfaces to obtain uniform divisions on the surface.
3. Objects with edit poly modifier on top. This type of surfaces must have quad polygons. If the surface contains singularity point(s) (A point which more than four polygons intersect) then UV directions cannot be computed along the surface. In this case you can use the surface controller in 1D mode and the array counts must be set to one dimensional array.

Also as a general rule, surface controller in 2d Arrays cannot be used on objects which have more than one smooth manifold (surface), for example a cylinder with top and bottom caps does not represent one surface while a cylinder (tube) without caps can be described as one single manifold.

In PARA 2.6 you can replace the items of the array with a new object with same modifier stack.
This video shows the procedure.