The MMD Physics Engine keeps Skirts from going through legs!

An MMD Feature Article by Winky on!Why does my model look so stiff? Can I adjust the MMD Physics Engine to automatically take care of my model’s fabrics and hair? Do I always have to adjust every bone in the model in order to get a natural pose?


How to keep Skirts from going through legs …
Adjust Gravity & Wind Effects …

Adjust The MMD Physics Engine!

Set the Physics Settings for a Natural Pose

Have you ever opened up MMD and decided, With the Physics turned off ... almost nothing on your model will look natural.“Hey, I’m going to pose  a model with a skirt, sitting on a chair!” and have this happen.


Oh noes! Now we have to take each skirt bone and individually adjust it! That will take forever!

Actually, there’s a fancy trick to fixing this.







Open the Physical Operations Tab to make adjustments to your physics settings.

First, before you sit the model down, turn the Physics settings on. Don’t know how? Let’s adjust the MMD Physics Engine.  Click the “Physical Operation (P)” tab, and then click anytime (To turn it back off, just select “Only Playtime” or “No Calculation”).




With the Physics switched "on", your model will look more natural with little effort!



Now gently sit your model back down again and…voila! No tedious work!








Sometimes your beautiful pose needs a little something to make it more dramatic ...



While I’m still on the subject of the Physics Engine, why not talk about wind? Say I pose a model in a nice little pose, like this…

…But I want to make it more dramatic, so I decide to add some wind, but how?





You can create "wind" by adjusting the directions of the Gravity settings.

Easy. Go back to the Physical Operation tab and click gravity settings. After you do, something like this should come up.




Wow! ... The "wind" adds so much life to your model's appearance.


Now, it’s time to adjust the wind.
-slide along the X axis for the wind to go LEFT and RIGHT
-slide along the Y axis for the wind to go UP and DOWN
-slide aling the Z axis for the wind to go FORWARD and BACKWARD

This was the final outcome.




Careful ... your model will look bad if you turn off the physics!


On a final note, if you use a PMD model, don’t turn the physics off unless you want to start over with them because this will happen.

If you turn the physics engine off with a PMX model, the bones will not reset.





Also, in case any of you are curious, this is what the tabs on “Physical Operation” mean.
-Anytime: The physics are on at all times.
-Only Playtime: The physics are on only when you play an animation.
-No Calculation: The physics are off at all times.
-Display Bodies: Allows you to see the “physical physics”.
-Initialize Bodies Position: Not quite sure. If you know tell me.
-Floor: Click to make the floor not be affected by gravity. For example, if you sit a model down on the floor his/her dress will fall through instead of spread out.

Model Credits:
Sweet Ann: Saboten (さぼてん)
Chair: 3D-Custom Girl, ripped by


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