Inaccuracy of vrm character's left hand

[peirongxu]

When I raise my left hand, it keeps low and almost not moving.

When I change this line (src/HandSolver/index.ts line 26) handRotation.y -= side === LEFT ? 0.4 : 0.4; to handRotation.y -= side === LEFT ? -0.4 : 0.4; It seems correct for left hand but error for right hand. Since they are both 0.4, why there is a condition judge? And why handRotation.y needs to reduce by 0.4?