Add custom tilesets without overwriting existing Blocks/BGOs?

[Nugget115]

Does anyone know an easy/simple way to add custom tilesets to a new group in the tileset item box without overwriting existing Blocks/BGOs?

I tried to add some of PROX's fantastic GFX pack to a level I'm working on, and it just overwrites various IDs in multiple groups - This defeats the purpose of adding new content, because I lose just as much as I add. Anyone got the piece of the puzzle I'm missing?

[wurstmechanic]

There are customizable blocks, BGOs, and NPCs in the tileset itembox (in the default PGE UI it looks like a ? block with a magnifying glass on it). With my experience, editing these customizable sprites can get really funky and there is only a limited amount of them. Overall, I suggest editing the blocks and stuff you know for a fact you won't end up using ever, but if you want to have a custom sprite on for example, the SMB3 wood to be some metal blocks, you can keep those metal block images in a level's custom folder (the folder's name comes directly from the .lvlx name) and the custom metal blocks will only be in that level.

Hopefully this helps!