[Joaquin Revel] “did the steps needed to do the slow motion with say 4% speed, but once it renders the video, just lags up it reaches the slow motion clip. “
Not sure what you mean? what does “just lags up it reaches the slow motion clip” mean?
If Twixtor works at 20%, it should work okay at 4%. Of course if there are any artifacts they will become more obvious at 4% than at 20%.
Basically Twixtor behavior is that it inbetweens frames with linear interpolation. ARe you seeing what seems like speed changes or shifts at each of the original frames when you slow mo to 4%? If so, then perhaps that’s too drastic for Twixtor. You might try slowing down by 20%, render out, read it, and slow down again. Although can introduce it’s own set of problem.
Twixtor Pro is not offered for Vegas Pro (because it doesn’t have the support we need). You can read more about Twixtor Pro features for After Effects here to understand the differences, but basically we supply more features so you can hand-tweak the results using mattes and splines. https://www.revisionfx.com/products/twixtor/features/#ae_compatible_4
Pete Litwinowicz