| Using Intent Chains for Quick, Robust Selection
Have you ever wondered what the "INTENT CHAIN" you see now and then means? Have you ever tried
to use it and found that is seems to do nothing?
The INTENT CHAIN is a powerful geometry selection tool for selecting a collection of edges all at once.
The real power of intent chains are two fold:
- First, they allow you to select families of edges with a single pick.
- Second, they don't care too much if the underlying geometry changes.
In a nutshell, when a feature with a sketch is created (like a protrusion extrude), some associated
chains of edges are also created. These can be selected as a collection. (For more info, Please see the
section from Pro/Help below.)
Figure 2 shows a protrusion with edges of different colors. The red ones represent one collection
of edges making up an intent chain. The blue another, and so on. If the edges of the protrusion are rounded
using an intent chain (as in Figure 3) all the edges can be selected with a single pick.
Even more impressive, if the section of the protrusion is totally changed the intent chain and therefore the round
will update automatically (as in Figure 4 where the geometry has changed, but the intent, a round about the
bottom, is the same).
How do you make it work?
Although it defies reason, PTC it seems has tried to bury this functionality. To make it work, you must
do 2 things:
- First, Set the config option "logical_objects" to "yes".
- Second, Force a complete regeneration of the model using #Info, #Regen Info (older versions)
or Utilities > Model Player (2001) to start a regeneration of the model from the beginning.
(Info from Technical Point of Interest (TPI) 104538)
Try the techniques. If it doesn't seem to work check the config and force a regeneration. This can be
a great time saving and model stabilizing function.
Have a great MAY!
COPY OF PRO/HELP INFORMATION ABOUT INTENT CHAINS:
Intent Chain and Intent Surfs
The Intent Chain and Intent Surfs options are a way to select multiple associated edges or surfaces
in a model. These options are available on the CHAIN menu (for Intent Chain) and on the SURF OPTIONS
menu (for Intent Surfs).
When you create a protrusion, you start with a sketched section or a surface and then extrude that section
or surface. Intent chains and Intent surfaces exist within this protrusion. Also, when
there is an intersection of a feature or surface, the edges created by that intersection can form an intent chain.
Intent Chains
There are three basic sets of intent chains:
- START EDGES - The edges around the portion of the protrusion containing the original sketched section.
- END EDGES - The edges around the side of the protrusion where the section ended its path.
- SIDE EDGES - The edges that appear as a result of the path of the protrusion. These edges exist from the start edges to the end edges.
In some cases, there are also other sets of intent chains:
- START INTERNAL EDGES - For an extruded quilt, the edges that appear at the beginning of the extrusion of the internal edges.
- END INTERNAL EDGES - For an extruded quilt, the edges that appear at the end of the extrusion of the internal edges.
Intent Surfaces
There are three sets of intent surfaces:
- START SRFS - The side of the protrusion containing the original sketched section or surface.
- END SRFS - The side of the protrusion where the section or surface ended its path.
- SIDE SRFS - The sides of the protrusion between the start surface and the end surface.
Note: If you create a feature based on an intent chain or surface, and the underlying edge or side
changes, the feature based on the intent chain will not fail regeneration. Only the intent object will fail,
but when you rebuild the intent object, all the associated geometry will reappear.
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