self weight to members

Question

Hi, 
 
 In staad pro physical modeler I have made a load case name : Self-Weight and gave it a -1self-weight multiplier to Y direction. Does this mean that the program will automatically calculate the weight of each member and assign it to it? Do I need to assign it somehow to my members and how? 
 On the other hand there's a button ACTIVATE SELF-WEIGHT in loading tab. should I press it for this to be activated? 
 Thanks,

Modestas · Accepted Answer

The selfweight multiplier -1 applies the selfweight to all structure automatically. If you click Activate Self Weight button, it does the same for the active load case - sets the selfweight multiplier to -1.