Pick a structure family and drag the parameters. Frame mode draws the bending-moment diagram on the tension side with reactions; truss mode colours every member by axial force — blue tension, red compression.
For portals, look at where the moment diagram crosses zero — those inflection points are where you want splices. In trusses, the end diagonals almost always govern; check them first. Remember this is first-order elastic: long compression members need a separate buckling check before you believe the force is usable.
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