There are two options for defining the emissivity for a RADIATE card created on individual elements or geometry:

The Pick loads button opens the HyperMesh Load Selector panel. Pick the RADIATE loads to which you want to assign emissivity, and click proceed.

The corresponding Reset button resets the selected loads.

The Update button assigns the value specified in the Emissivity: field to all selected RADIATE loads.

The Update button assigns the value specified in the Emissivity: text box to all the RADIATE loads in the current load collector.

In a similar way, for shell elements, it is possible to change the element face (RPOS or RNEG) on which the RADIATE load is applied.