Explosives is far from useless on smaller missiles, it does extend the damage dealt, this is from practical testing, not just math. The max radius is easier to reach than you imagine. But if you like math I can tell you it would take a sniper missile of both missile and beam modules equaling 26525 each for a total weapon size of 53050 modules to deal 7,957,500 damage. I'm not about to build a missile launcher that size to test though. A pulse missile would surpass that at 8842 each or a total size of 17684 dealing 7,957,800 damage.
radius is used in two ways in starmade
first is the size of the impact, where the max radius is used to determin what is hit. this is only really useful in multi-ship scenarios and for turret destrustion, as two turrets on a ship both 50m away from the missle impact site will be effected and have independant damage rolls
now my math isnt perfect as i cant figure out of the damage for each of those two turret hits are calculated first or second, and weather or not the damage they take is removed from the damage total for the initial hit or weather each hit recieves the full damage of the missles blast.
what i do know however is that the holes created by the impacts are created in a layer by layer manner where a sphere of damage is moved one layer at a time through the object and damage is done based on what blocks intersect the sphere of damage, the damage sphere continueing untill it either runs out of available damage or hits its max radious from the impact point (thus meaning at max it can make a perfect half circle)
so what using explosive does is it increases the size of that damage sphere, this creates a slightly wider but shallower hole in the target. at lower damage levels (sub 8mil) this creates a situation where you may have a hole thats 1-5 blocks wider but 1-3 blocks shallower than any other missle combo of equal damage (except one special exception where 1 missle build can create a hole 60% larger than explosive untill it hits that 8mil damage cap)
that means its almost always better to use alturnate effects then explosive, xplosive being a "jack of all trades" type of missle and a "nuke" aka >8mil damage missle
even then your better off using ion to bleed of excess damage over the 8mil cap converting it to a higher level shield damage becuase the difference between 40m radius and 50m radius isnt all that important when most ships arnt big enough to ensure that a gigantic 80m by 40m sphereical hole in thier ship isnt crippling.
also in order to make it a 50m by 100m hole using explosive you need 15,062,500 damage otherwise your just creating a 38m by 84m sphereical hole in their ship trading penetration for a wider impact radius. you need somewhre around the 10mil damage mark to overtake a 40m radius missle in penetration.[DOUBLEPOST=1415780109,1415777695][/DOUBLEPOST]after some quick testing the damage on multiple targets (or turrets on a ship that gets hit) are done simultaniously using the exact damage sphere that calculates the primary impact, if that sphere intersects a second object (such as a turret or a nearby ship) then when it calculates that layers damage it does it n all things within the sphere of influance one layer at a time expending the missles potential damage to do so.
what happens is that the missle impacts a point, and the damage calculates layer by layer radiating from the centermost point of the sphere outwards one layer at a time. untill it reaches its either maximum radius or its damage threshold.
this means ultimatly all missles that do the exact same total damage have the exact same sized hole at the end all the way tunill that magic number just under 8 mil damage, i was achieving slightly different results before because of an error in my testing method wich i corrected.
meaning explosive is 100%useless before you hit 7957500 damage as you never get the chance to do damage past a 40m radius without at least that much (assuming only 1 layer of hardened hull on a flat impact point) if the target isnt flat or has multiple layers of hardened hull you actually need MORE damage before explosive becomes worthwhile so that number is an absolute minimum. if the target is using lesser hull then you only need just over half that damage to inflict maximum radius however (est 4.5mil dont feel like running that math again)
keep in mind each layer contains more "blocks" than the one before it so its not a liniear equasion, meaning you can get CLOSE to max radius with smaller damage missles as each layer requires more damage to fully remove than the last you can create a 35 radius hole with ALOT less damage than it takes to make a 40 radius hole