4.9 Mass not affecting skeletal ragdoll

I recently ported over some characters with physics assets to 4.9

I noticed that regardless of what mass I set the ragdolls to (even .1 mass scale or a weight of less than 1KG), my impulse does not affect them in any noticeable way unless I crank the impulse multiplier up very high.

In 4.7 the ragdolls would be blasted away from the impulse just fine. I cannot seem to fix this issue.

Help appreciated!


I have been unable to reproduce your issue. Could you post a screenshot of your ragdoll setup so I can ensure I am setting mine up correctly?

Here is an image with some settings.

The mass and mass scale does not seem to affect the model. The grenade has an impulse of 4000 which needs to be cranked up in 4,9,2 to see a similar effect.

Also, here is a video comparison of the issue using the same settings in 4.7.6 and 4.9.2:

Even with a super high or low mass value, there is no change. The only way to make it work is to crank up the impulse of the grenade to 40000-80000, which breaks the weight scale for lighter objects.

Edit: This is the same effect for any skeletal ragdoll, not just my custom one. It includes the standard third person “Hero” ragdoll.

I’ve tried to reproduce your issue, but I was unable to do so. I had a radial impulse of 4000, and it moved my skeletal ragdoll properly. Could you try to set up a simple test project in 4.9.2 with a skeletal ragdoll and a radial impulse and see if you get your desired effect without importing the assets from a previous version?

I did a new setup, and using the normal 3rd person blueprint template w default physics asset, it took 40000 force to make it move like it did in 4.7.6

I noticed that setting the mass and mass scale doesn’t work from the instance settings but only from a physical material. This seems odd to me.

  • What is your Falloff set to on your Add Radial Impulse node?
  • Have you ensured that you check your Vel Change box on the same node?

If none of these options are causing the issue, could you zip up the test project you created and send me a link to Google Drive or Dropbox so I can take a look at your settings and see what the issue is? Thank you.

The initial error of the grenades not impacting the ragdolls is gone when using a new project, so that must be some error when converting the project to 4.9.2.

Some quirks still remain though, and I am very confused on how to set the weight of a physics asset. I can’t seem to get results when changing the mass or mass scale manually on the level actor.

It only will change at all if I change mass ratio in a physical material or by changing the bones individually in the physics asset.

That said… I went ahead and made a project for you to look at!


Each map has three ragdolls and three bottles, set to different masses in the level. I have annotated the scene some to hopefully make it easier for you.

There are 3 main maps located in content folder ThirdPersonBP/Maps:

  • 40000MassGrenade (default map; 40K impulse on grenade)
  • 4000MassGrenade (same as before but 4000 impulse on grenade)
  • NoGrenade (no grenade, so you can examine impulse buttons easier)

You can use the levels to compare the strength of the grenade impulse.
Also, you can apply a radial impulse to all of the bottles/people pressing:

  • M for 4000 strength
  • N for 99999 strength

Hope you can help clear this up for me! My game is based around physics interaction, so getting ragdolls to have proper weight is important.

Thanks again! I look forward to hearing your findings.

  • What version did you create this project in before converting it to 4.9.2?
  • Can you provide me with a copy of that original pre-conversion project?
  • You’re saying that setting the mass of the bones individually allows you to get the result you’re looking for?

Thank you.