Enveloping of results does identify for a selection of loadcases (with optional scaling factors) the minimum or maximum (user choice) result value per element or node.
In HyperView, enveloping is available under Results > Loadcase.
In HyperMesh, enveloping is available in Post > Results Browser: right click: Create Derived Loadcase.
However, HyperView and HyperMesh follow different approaches, described following.
HyperView does envelope for the currently contoured result type.
That means, it does compute the envelope only in the moment you choose to contour a result type, for this very result type.
The aim is, to show always the enveloped value for the result type that is currently contoured.
(If you are out for other result types being reported in the same subcase as found for an initially enveloped result type (meaning they are not necessarily the minimum or maximum values), you need to display the results of that subcase directly.)
HyperMesh does envelope for a selected result type (user choice), and reports along all additionally available result types in the subcase found by enveloping for the selected result type.
That means:
The aim is, to provide for the selected enveloped result type the additional result types in the same loadcase, for example for use in further assessment approaches.
(If you are out for the individual envelopes of multiple result types, you need to create one envelope for each result type of interest.)