1.1.4.4 Using Alignments on Graphical Primitives

Once the alignment is fully defined, project objects can be set up to position themselves on the alignment. If a graphical object is along the bridge alignment, it needs to have an Alignment parameter with the name of the alignment as the value. There could be more than one alignment defined in the project.

Parameters

1. AlignH: allows control of the horizontal curve of the alignment on the object

2. AlignV: allows control of the vertical curve of the alignment on the object

3. AlignT: allows control of the transverse slope effect of the alignment on the object

Values for parameters

1. None: The object will be moved to its location on the alignment but it will not align (rotate) to the alignment.

2. Orient: The object will be moved to its location on the alignment and it will rotate to match the heading.

3. Warp: The object will be moved to its location on the alignment. It will not only rotate but also warp to match the horizontal or the vertical alignment.

While Orient may be the best option for most bridge components, Warp option works especially well for bridge deck or the roadway surface as each object needs to closely match the alignment curves and cross-section.

Examples

Example 1

Below are three volume objects (in blue) marked A, B and C. These objects are positioned on a curved horizontal alignment.

Figure 1.1.4.4.1: Objects positioned on horizontal curved alignment.

• Volume A's AlignH parameter is set to None, that is why it is positioned on the alignment but not aligned with the alignment.

• Volume B's AlignH is set to Orient, so it is positioned and aligned with the alignment definition.

• Volume C's AlignH parameter is set to Warp. That is why it is positioned, aligned and also warped to match the alignment. Notice that the edges of C is longer on the outside of the curve than inside.

Example 2

AlignV parameter provides similar effect along the vertical curve.

• AlignV set as None is positioned vertically but it is not oriented to match the direction of the vertical curve.

• AlignV set as Orient matches the direction of the vertical slope at the center of the graphical object.

• AlignV set as Warp will orient and also warp to follow the shape of the vertical curve.

Example 3

AlignT parameter provides similar effect on the cross-slope. Below are three volume objects (in blue) marked A, B and C.

Figure 1.1.4.4.2: Objects positioned on transverse slope.

• Volume A has AlignT set as None, so it is positioned vertically but is not oriented to match the cross-slope.

• Volume B has AlignT set as Orient, so it matches the cross-slope.

• Volume C has AlignT set sa Warp, so it will orient and also warp to follow the shape of the cross-slope.