Failure here, big one ! A rock on the set blocked the character's rail support from his course at the end of the sequence. When i realized that, i though to myself that i didn't spent these last hours for nothing and have to "try" to let the rock slide a little bit, each frame til the rail could overpassed it. Total disaster.
I'm gonna scrap these 20 frames and restart at the 45th frame of that 70 frames sequence. 8 hours invested on the "shooting" of this sequence yet and lost almost 3 hours this week on it. I'll try to finish it this week but, maybe not tomorrow. Too pissed.