It excludes liquid ingredients (so something using sulfuric acid would never drop sulfur) and will not break down any recipe of type "chemistry" or "oil-processing;" this may change in the future depending on how the game changes.
As separate but similar effect, it also gives trees a wood drop (less than their minable/choppable result - most trees will drop between 0 and 3 wood instead of their nominal yield of 5), so deforestation projects will leave a lot of wood on the ground - this may or may not be a pleasant side effect, depending on your disposition regarding wood.
So far, I'm pretty happy with it.
- Mod load order - doesn't affect mods that load after it, of course. Mods which load after it and alter basic game recipes will make it inconsistent with the modified recipes. However, it should work well with any mods it does get processed after. update: should work with F-mod and DyTech
- Any item with multiple recipes may be processed weirdly - Scrap Mod only uses the first recipe it encounters. In current vanilla this is not an issue, but it could become one later or with mods.
- Items with less than one of an ingredient per item and/or recipes in their chain containing very few ingredients (such as telephone poles) could be set either have zero potential drops or percentage chances to drop each of its intermediate ingredients (a telephone pole built from 1/2 unit of wood and 1/2 unit of copper having small chances to drop each of: processed wood, raw wood, copper cable, copper plate, and copper ore), so if the game "rolls" well, the scrap could potentially be more than was input). I'm not sure which way to go on this; while it enables weird situations where a net gain is provided, each drop's probability is small enough that statistically over time this should not be an issue (even accounting for productivity modules) but it does make for the odd inconsistency. The currently uploaded version allows for these possible overdrops.
- This adds loot entries to buildings, none of which have drops in vanilla. If a mod or future development grants buildings drops, together the result will probably be too much.
- Construction robots replacing a destroyed building will also overwrite the scrap, making Scrap Mod less useful. I am considering adding a collector item such as found in other mods to help with this. Bot collection behavior in the future would be nice.
- Batteries, as a "chemical" recipe, would currently be considered a base ingredient except that I have coded an ugly exception for them to generate copper and iron scrap. Commentary in the lua files suggests batteries will be changed to an assembler process, at which point this blemish can be removed.
- Because this mod changes basically every placeable building, those buildings will show up with the mod's tag on it, which could be distracting, annoying, or confusing, especially when combined with other mods.
- Recycling - introduces the recycler, a furnace-like item that can reduce anything placed in it to ore or scrapmetal, which can be separated in an assembling machine to component ores with a little sulfuric acid (currently only supports copper and iron, won't give you back any of the special stuff other mods may add).
- Improved recipe parsing - items should never drop more than their ingredients could make, ever.
- Chest contents reclamation - when chests (or vehicles) are destroyed, spill a portion of their contents to the ground. This includes fuel inventory and modules.
0.2.2:this version works with Factorio 0.11.x
- Collectors, as mentioned above