Animation and Render

Hi all,
I am working on an animation of a beam engine. The animation works perfectly in the viewport but when I render the animation, eevee or cycles, parts of the animation render wrongly. Interestingly if I manually scroll through the individual frames and render them out as images they render fine.
For example here is a render of the image of Frame 16.


and this is a copy of the same frame from the animation render

This is typically caused by a cyclic dependency.

Check and see if you have any. A situation where bone (or object) A has a constraint targeting bone B, and bone B has a constraint targeting bone A. There may be more than two bones, i.e. A > B > C > A.

A typical way to check quickly is to jump around to random frames in the timeline and see if the rig is ever out of place, or to step a few frames forward, then a few frames back, then a few frames forward again and see if you can notice it lag behind by a frame.

@Antaioz I don’t think that this is the problem as the animation functions as expected when testing in the viewport and also I have tested in 2.79b and it is fine there. However I will do as you suggest and check for cyclic dependency.

I have checked for cyclic dependency as suggested by @Antaioz but didn’t find anything so I wonder whether it might be still to be sorted out by the developers.

Here is a screen capture of the animation running in the viewport in solid random colour display.