skeletal mesh material dissolve based on projectile impact point

I require some help having a skeletal material dissolve to occur on first person projectile impact point. The fx works fine if i use a material sphere mask with world position, however i would like to use the skeletal mesh UVs to decide where the impact point occurs. I hope that makes sense. The images below is how its currently setup but I can’t get the mask location to change location on projectile impact. Any help appreciated.