This is one of over 4594 effects generated by Filter Forge, a Photoshop plugin that allows you to create your own filters.
To open this filter, you must have Filter Forge 2.0 or higher installed on your computer. If you don't have it installed yet, click here to download Filter Forge
This snippet lets you choose exactly where you want each of two particles to be bombed, W/O any blank spaces. Just replace the "switch" component with a gray-scale range of your choice.
snippet, bomber, particle, border, sorting, chance, selection