Hi Pierre,
So I followed what you said. I have 3 layers:
Layer 1 is a pre-comp of the footage
Layer 2 is a rotoscoped of the layer 1
Layer 3 is the footage
I applied Twixtor 4.5 to the Layer 2 and 3 and set the ALT motion source to Layer 1.
It works for Layer 2, but Layer 3 show that pinkish-red, nothing. It doesn’t make sense at all to me, if Layer 2 is working why not Laayer 3?
I followed the tutorial, the ‘Alternative Input’ is not documented as well as other sections, no After Effect project. I really don’t get it. ;(