EDIT 2: UPDATED TUTORIAL IS HERE:    • How to Convert MikuMikuDance (MMD) An...  

EDIT: I realized how confusing this tutorial is, I plan on remaking this tutorial!

WithOUT having to pay an arm and leg AND your first born child!
That's right, this method is FREE!!! YEY!!!

LINKS:

Sims 4 Studio: https://sims4studio.com/board/6/downl...

MMD: https://learnmmd.com/downloads/

PMX Editor: https://www.deviantart.com/inochipm/...

MMD Tools (Blender Plugin): https://github.com/UuuNyaa/blender_mm...

Rokoko Blender Plugin: https://support.rokoko.com/hc/enus/a...

Sims 4 MMD Bases: https://www.deviantart.com/applewater...

Here's a list of MMD's Japanese bone names (so you can retarget them correctly):

DON'T WORRY ABOUT TARGETING THESE BONES:
全ての親
グルーブ
左足
左つま先
右足
右つま先
左足IK親
右足IK親
左肩P
右肩P
右足D
右ひざD
右足首D
左足D
左ひざD
左足首D

TARGET THESE BONES (to the respected Sims joint):

センター b__ROOT_bind__
上半身 b__Spine0__ (IF 上半身 has a at the end, then b__Spine1__)
首 b__Neck__
頭 b__Head__
下半身 b__Pelvis__

LEFT SIDE:

左目 b__L_Eye__
左肩 b__L_Clavicle__
左腕 b__L_UpperArm__
左ひじ b__L_Forearm__
左手首 b__L_Hand__
左親指 b__L_Thumb0__
左親指 b__L_Thumb1__
左親指 b__L_Thumb2__
左人指 b__L_Index0__
左人指 b__L_Index1__
左人指 b__L_Index2__
左中指 b__L_Mid0__
左中指 b__L_Mid1__
左中指 b__L_Mid2__
左薬指 b__L_Ring0__
左薬指 b__L_Ring1__
左薬指 b__L_Ring2__
左小指 b__L_Pinky0__
左小指 b__L_Pinky1__
左小指 b__L_Pinky2__
左足 b__L_Thigh__
左ひざ b__L_Calf__
左足首 b__L_Foot__
左つま先 OR 左足先EX b__L_Toe__

RIGHT SIDE (Basically the same as the left side, EXCEPT you're replacing 左 with 右):

右目 b__R_Eye__
右肩 b__R_Clavicle__
右腕 b__R_UpperArm__
右ひじ b__R_Forearm__
右手首 b__R_Hand__
右親指 b__R_Thumb0__
右親指 b__R_Thumb1__
右親指 b__R_Thumb2__
右人指 b__R_Index0__
右人指 b__R_Index1__
右人指 b__R_Index2__
右中指 b__R_Mid0__
右中指 b__R_Mid1__
右中指 b__R_Mid2__
右薬指 b__R_Ring0__
右薬指 b__R_Ring1__
右薬指 b__R_Ring2__
右小指 b__R_Pinky0__
右小指 b__R_Pinky1__
右小指 b__R_Pinky2__
右足 b__R_Thigh__
右ひざ b__R_Calf__
右足首 b__R_Foot__
右つま先 OR 右足先EX b__R_Toe__



Previous Sims (4) (Animation) Tutorials:

Sims 4 Animation Tutorial Part 1 (Adding Hair physics to sims rig):    • [Sims 4 Animation Tutorial (Part 1) (...  
Sims 4 Animation Tutorial Part 2 (Adding foot IK and eye control bone):    • [Sims 4 Animation Tutorial (Part 2)] ...  
Sims 4 Animation Tutorial Part 3 (Adding morphs for more simple animation):    • [Sims 4 Animation Tutorial (Part 3)] ...  
Sims 4 Animation Tutorial Part 4 (Adding custom animation for use in game):    • [Sims 4 Animation Tutorial (Part 4)] ...