Please take a look at the attached file. To randomise the size of the bricks per row I've used the following technique.
1 - Create a transform operator and wire it between the brick and the generator.
2 - Right-click the Transform operator and Export Y Fixed Size
3 - Go to the Transform operator's properties and check Fixed Size
4 - Wire a Random Number node to this input and set the Type
to Scene Units
and change the Mode
to Array Y Row
. Set a minimum and maximum height for the bricks.
As for how to create a vertical wall, you have a few options either create it using a single spline for the path and a Y Size parameter, in which case you'll want to use the X Rotation properties to make the wall vertical. Or create it using two splines, and then edit the Y spline to move the wall into a vertical position, or if you want to use X and Y size parameters or a clipping spline, you'll need to rotate the RailClone object itself so that it is vertical .
Please see the attached files for samples of all of the above.
I hope that helps,