Skeletal Mesh floating above ground on BeginPlay caused by AI Controller

Development Programming & Scripting AI
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After having problems that my character starts floating above ground when starting play, I could reduce my problem to a minimal setup with a very basic cylinder skeletal mesh (40 cm height) with just 2 bones, even removed the animation blueprint for the simple test animation to reduce further.

Also having no physics asset for this test mesh, as I did suspect that floating to be caused by that, which is not the case.

Made blueprint BP_Cylinder for this (derived from Character class). Adjusted Capsule Shape and Mesh Transform so that the capsule matches the cylinder for collisions and can be properly placed on ground:

300359-capsule-adjust-to-cylinder.png

Create a copy of BP_Cylinder, and just change settings for Auto Possess AI and AI Controller Class. Keeping default AI controller for the test. Placing both blueprints into the level, and on starting Play, the one, that’s getting possessed by the AI Controller immediately begins floating above ground as in the following picture:

300360-problem-picture.png
300360-problem-picture.png1133Ă—380 300 KB

I have absolutely no idea, what I could be missing here.

Edit:

I could reproduce this on 4.24 as well.

Edit #2:

Enabling physics for the capsule makes the mesh just jump shortly when starting play, then it falls down to ground. But I actually do not need physics simulation on this and want to keep this disabled.

Edit #3:

Actually, the Character Movement Component seems to be involved here - changing Default Land Movement Mode for this component from Walking to None makes the mesh stay on ground. Changing this in the blueprint after a sleep back to Walking makes the character jump up - so even after placing the character in scene and later switching to a movement mode would cause a visible artifact.

Thanks a lot for any ideas.

1 Like
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Hey herb, have you been able to figure this out?

I’m having the same issue, also traced it back to the CharacterMovementComponent and the AIController, AND for me it only occurs with a custom collision channel, the built-in channels work fine… (Using Engine 4.25)

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Hi, unfortunately not. But I did not really go much further into this.

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That’s too bad… I finally figured out my issue: I had a huge TriggerVolume in my level which I didn’t notice. Since my custom collision channel had a default Block response, the volume was blocking it and made my Character stand ontop of the volume… (it wasn’t very high, just above ground level: hence the effect of “floating” above ground)

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I don’t know if it will work for you…
I had a float issue with the skeletal and animations in begin play (derived from retarget). I solved it by changing the skeleton options.
In the Skeletal Tree:
->“Options” → clic in “Show retargeting options” and try change Recursively Traslation Retargeting with right clic (in some bones). Try with all the options (“Recursively set Traslation Retargeting Skeleton”, "Recursively set Traslation Retargeting Animation… ANimation scale…etc).

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MMM in my