I want to select linked mesh in an object using an empty in geometry nodes. As soon as the empty sphere touches a face it becomes black, after that want to check if the current mesh has any black values, if yes I want to select it and apply a material. I am able to do the first part but unable to select the whole linked mesh
use an accumulate field node. This node adds up all the values within a group ID. What you want to do is set ot to integer and use the selection you have (black face) as the value then compare the total to see of it's more that 0. if you want to select per mesh island, then use the mesh island node and use the island index and the accumulate field's group ID(index).