T-FLEX Parametric CAD. Fundamentals. 2D Design

Fundamentals. Two-Dimensional Design
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The first one is using a layer's own attributes (“Hidden when model is used as a Fragment”, “Visible only
when model is used as a Fragment”). This way does not allow defining several configurations of the
fragment image based on the same drawing. Nevertheless, it allows hiding/showing the elements of the
fragment part drawing that are definitely necessary in the part drawing, yet must be hidden in the assembly
(or vice versa). This can be, for example, the part dimensions, the title block, etc.
The second approach is more flexible, and can be used when positioning the fragment by a fixing vector. The
fixing vector parameters can relate the vector with selected layers (see chapter “«Bottom-Up» Design”).
Thus, a number of part configurations (such as part views) can be obtained from the same drawing by
creating several fixing vectors with different types of relation with the layers in the drawing.
Control over the visibility of the fragment drawing elements is done by using visibility levels in a way
common across all drawing elements. This approach may require use of external fragment variables. Such
external variables can be created in the fragment drawing, and then carried over to the assembly, in order to
control the visibility levels of the fragment drawing. The visibility levels of the fragment drawing elements
will obey the external variable settings both while editing in the assembly context and in detailing (in the
exported assembly fragment instance).
Hidden Line Removal in Assembly Drawing
One of the important advantages of T-FLEX fragments is the hidden
line removal mechanism when building an assembly from fragments.
This allows, on one hand, creating a complete drawing of the desired
part, while, on the other hand, “hide” the drawing lines that fall
behind the image of other parts of the assembly drawing.
The area in the drawing subject to hidden line removal is defined
using a hatch. To remove hidden lines, you can use an existing hatch
or create an additional invisible one (using the fill method
“Invisible”). In the hatch parameters, set the flag “Use for hidden
line removal”. In this case, the invisible hatch will be hiding behind
the objects with lower priority.
Control over the visibility of a covered up element is done by setting
an appropriate priority in its properties. If a fragment is supposed to
cover assembly lines, then the fragment priority should be set higher
than that of the assembly elements, which the fragment should cover.
Vise versa, if the assembly lines should cover the fragment lines, then
one would have to create a hatch in the assembly drawing itself, and
then set its priority higher than the priority of the respective fragment.