The Bone-Hiya attachment is based on the (棒火矢 Bō hiya) which fires a fire arrow from a cannon. The Bō hiya would have exsited in the same time period which Sekiro takes place in; the Sengoku period. The Bone-Hiya could either be used as a crowd control weapon to snare enemies or an sticky remote rocket launcher with area of effect damage.
The Low Poly models including some Retopo was done in Maya. I considered this an Hero Assist so the poly count is higher then it would normally be for an arm/weapon of a 3rd person character. Also the extra polys helped for close up pictures.
The models were UV’d in Maya & HeadusUV. All the maps were baked in Marmoset Toolbag. All the texturing was authored in Substance Painter. Since this is a Hero Assist the final textures maps where exported at 2k resolution; but can be down-scaled in engine if need be.
Arm TXTRS @ 2k : Base Color, Normal, AO, Rough, Metal
Bone-Hiya TXTRS @ 2k : Base Color, Normal, AO, Rough, Metal