Hey, this issue has been around for a while now, so I just want to explain how to fix it.
The cape is simply not interpolated correctly at a certain point in the code. To fix this you only have to change one line in the following method: net.minecraft.client.renderer.entity.layers.CapeLayer#render
Add the interpolation to the body rotation by multiplying the rotation with the partialTicks variable. That's it! You can also take a look at my screenshot of my changes to the code:
Hey, this issue has been around for a while now, so I just want to explain how to fix it.
The cape is simply not interpolated correctly at a certain point in the code.
To fix this you only have to change one line in the following method:
net.minecraft.client.renderer.entity.layers.CapeLayer#render
Add the interpolation to the body rotation by multiplying the rotation with the partialTicks variable.
That's it! You can also take a look at my screenshot of my changes to the code:
!diff.png!
I really hope that helps to fix this issue!