So this may sound kind of stupid...
I've been working on a little side the past day or so adding in expanded/other mod metals as Weapons using BWM mechanics. My first attempt has been with Thaumium from Thaumcraft and it has worked out pretty darn good. As weapons they have the same mechanics as all other BWM items, except they retain the things that make Thaumium unique, damage, enchantability, and being valid for Repair.
I've only run into one problem... I seem to be missing how you would get the actual entities for the Knife, Spear, Boomerang, and Flail to change color to reflect the new Material that I'm using.
I feel like I'm missing something really obvious so if anyone has any pointers, I'd appreciate some help.
At the moment there is the ICustomProjectileMaterials interface you can implement somewhere. The getAllMaterialIDs should return all the integer IDs of the materials you use, probably the enum ordinal. The getMaterialID(ItemStack) function should return the ID of the material that specific itemstack has. The getColorFromMaterialID method should return a float array of length 3 containing the RGB components of the color for the renderer to use.
I am currently working on a material API that should make this all a lot simpler. You can find it on GitHub: https://github.com/Ckathode/balkons-weaponmod/tree/material_api
I would really appreciate some feedback about what you need and would like to see as a feature in the API.