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root motion help needed

Development Discussion Animation
#1

hello, i’m working on a third person game, i’m using as a player p`rototype a model and animation from mixamo website (the main reason for this is beacause on mixamo website i found all the animations needed for my game project).

i’m using normal animations for the basic locomotion (walk, run, strafe and so on) the player can do some specials moves, these moves are some acrobatic jumps and some slides to avoid obstacles and dangers; i want to use root motion on these specials move, but i’m facing some issues.

  1. if a check root motion on the animation click, the animation will play weird, i tried all the option but, if i enable that option on the animation window, the animation will broke and don’t work as expected.
  2. without to check the root motion option on the animation panel, the animation will play very nice, but at the end of the animation clip, the player returns to the idle animation but in its first position, (i need the player to return to the idle animation but in it’s last position, i mean, at the end position of the root motion clip.

i readed on some place that i must add a root bone for the mixamo models, because they don’t have the root bone.

any help will be very useful to help me to figure out this issue.

thanks i advance for all the help.

#2

Hi there,
When you enable the root motion in the anim previewer and this is assuming your skeleton has a root bone with animation, the preview WILL look displaced and weird, from what
i understand you are seeing the delta offset from the root bone animation. As long as there’s a RED colored line, which represents your root displacement. This is OK.
In game the character’s controller will be displaced by this root motion. Try and play the animation in-game and not rely on the animation preview for correct displacement.

Cheers

#3

hello, i tried the animation in game, the player moves and when it returns to the idle state at the end of the animation, the player is in the position where the animation has started.

In the animation preview i don’t see any red colored line, my model & animation are from mixamo and i don’t see any root bone on the rig, that is why i’m asking here for a fix or solution.

i’m thinking in removing the movement of the animation in 3d studio max and when the player do the special move, play the animation and apply a constant movement to the capsule, to try to replicate the right behavior for the specials movement; don’t know if this will work, is just a theory that i will try to verify if i can’t figure out the root motion issue that i’m facing.

thanks for the help.

#4

hello again, i fixed my problem, i will tell here how i got my issue fixed, just in case of someone gets the same scenario like me.

i bought the mixamo retargeting plugin from the marketplace, with this plugin i have retarget the mixamo skeleton to the ue4 mannequin, this plugin has an useful feature for the root motion, it adds the root bone, the one that is missed when you import a mixamo character because the mixamo rig has the pelvis as the root bone.

with the animation retargeted with the root bone, i tried many times but it didn’t worked, at this point, after searching a lot on the web and the epic forum i saw in some website that the root bone must have the traslation to let the capsule move with the motion of the animation. In my retarget animation i have the root bone but that bone didn’t have any traslation, that is why in the video that i have posted the animations moves and the line on the floor is white, you need to see a red line, if you see the red line you are goog to go, that wasn’t my case.

i exported the animation with the root bone to fbx and i have opened it on 3d studio max, i have set the keys for the root bone traslation on each animation frame, you need to take care of this part, because it must be done manually and after move the root bone, you need to return the pelvis bone to it’s prior location, because when you move the root bone all the animation will moves forward, just copy the location of the pelvis bone before you move the root bone to it’s new location, after move the root bone, select the pelvis and paste the location that you have copy before, just repeat this step for each keyframe that you have in your animation and you animation will work just fine.

remember you need to move on the Y axis (if you are moving forward, that was my case).

if you have any question about the method that i have used to get this working, you can ask it here.

#5

Yep, from the video it looks like you had hips translation but the root bone was at the origin. Glad to hear it works now.