don't really know what campaignname is

[blissful storm]

.

[regal yew]

if you map is in Maps/korne/pizzaplace/ then your assets should be spikes/korne/pizzaplace/ or korne/pizzaplace/custom - note that custom is should be replaced by the name of the spikes sprites

[dark solar]

to be more clear, the path can be anything - it's just that using your username and campaign name / mod name is a good convention to make sure filepaths in your mod are unique