You can make two versions of your damage effect (one with splash and one without) and two versions of the weapon your units uses (one linking to the splash damage effect, one not).
When you can create an ability (you could dublicate Stimpacks), make it apply a buff to your unit.
This buff will just enable the Splash weapon as long as it's applied.
What I would like is a "Full Auto Burst" ability for the Marine that appears as a btn-techupgrade-terran-fullborecanisterammo.dds button, that cost 5 energy(Im giving energy to Marines) and lasts 10 sec ( tiny red stimpack icon next to the marine image) with the splash being something like radius 1.7 and 0.3 of regular damage.
Im tripping in a maze of links between ability, effect, behavior, etc. I didnt get the effect (yet) but for some reason I no longer see stimpack for marines even when its reseached. I'll recopy the stimpack from another map to hopefully fix it.
Edit: This is strange I created a blank map with dependancies set to Wing of Liberty Campaign and researching Stim Pack on that basic map does not allow the ability to be seen for the marine?? Does anyone have a clue?
Edit2: Maybe its got something to do with the campaign tech selection, I'll try with regular melee if I can.
an ability "Full Auto Burst" that appears to be linked to a button "Full Auto Burst" and an Effect "FullAutoBurst(Marine - Full Auto Burst(Damage))"
which in CEffectDamage under the Searh tab in AreaArray has; Index 0, Arc 360, Bonus 0, Fraction 0.3, Maximum Count 7, Radius 1.8, Radius Bonus 0, Validator(none).
Any clue what is missing?
I notice that stimpack has an actor and a Behavior which appear to be linked to the ability, I have created a Full Auto Behavior but dont know how to link it to an ability, and dont know if this is required or not.