The settings in the Hatch, Cross Hatch and Pattern Area tools can affect the level that a hatch will be placed on and whether or not a new bounding line will be generated. 1. Tick Associative Pattern. a) If you use the by Element method the hatch or pattern will be placed on the same level as the element and will reflow if the element is modified. b) If you use the Flood or boolean methods the hatch or pattern will be placed on the active level and will create a bounding line on the active level around the hatch or pattern. This pattern and its boundary will not reflow if the element is modified. 2. Tick Associative Pattern and Associative Region Boundary. Whichever tool you use, the hatch or pattern will be placed on the active level and will create an invisible associative boundary linked to the bounding elements. When the bounding elements are modified the hatch or pattern will reflow. This is the most flexible option allowing you to separate the bounding elements and the patterns or hatches by level without adding unwanted boundary elements. 3. In some circumstances you may wish to tick the Snappable option on to enable snapping to the pattern elements, an example of this would be if you used the crosshatch tool to draw a ceiling or other grid. 4. There is also a change pattern tool that can be used to modify existing patterns. a) Tick the Attributes box, the tool will apply the current element attributes to the pattern, e.g. colour. b) Tick the Pattern Parameters box, the tool will apply the parameters currently set in the Hatch/Pattern tool settings, e.g. Spacing and Angle. c) Tick Intersection Point to, well..., change the pattern intersection point. Just activate this tool then select the pattern and snap to whatever point you wish the hatch/pattern to originate from. This point can be anywhere, it does not have to be within the hatched/patterned area.
5. There are also Match and Delete Pattern tools. (Note that the SmartMatch tool will also pick up any pattern settings.)
6. Flood Options, look at the pop-down section once Flood has been picked:
You have options to locate interior shapes and/or text, also to dynamically display the area that will be hatched.
Max Gap is the distance in working units (so usually mm) that the flood tool will jump when closing the flood area, this can be adjusted to an appropriate value to prevent the flood leaking out all over your drawing.
Zoom into the overall area that you want to flood so MicroStation has fewer options to contend with.