Probably worth mentioning CG unreal’s tutorial:
you could download the file here
is any way to make more than one object hit the shield in different position and creat the spheremask to the object to affect the vertex ?
I think there are no arrays in the material graph, maybe with a custom node.
Otherwise you will need to create a spheremash per impact effect. Then shuffle through them every time you add a new impact.
You can ofc limit the amout of impacts/spheremasks to something like 5. Which should be enough for most cases.
Another alternative would be, to use a render target with the new Niagara Simulation stages, which allows for additive texture manipulations at runtime. They have an example of this in the content examples.