Throughout the film "Big Mama’s House 2", Martin Lawrence’s on-screen wife is pregnant. In the original cut of this sequence, the following scene
appears 9 months after the birth of their child. The producers of the film appropriately cast a 9 month old baby to play the role of Martin’s child. In the original cut of the film made thematic sense. Unfortunately, The edit of the film changed. With the new editing, the last time the audience sees Martin’s wife she is still pregnant. Shortly after that the family appears to be coming home from the hospital for the first time.
Test audiences commented that the baby used in this sequence looked much too large to be a newborn. So the producers asked if there was anyway that we could “Just shrink the baby.” What followed was 5 weeks of intense compositing to get the shots done in time. (the producers originally offered only 3 weeks, but magically found more time when changes were requested.)
In order to Shrink the baby by 20% overall, we first rotoscoped him off of the background. Then stabilized his movement through space. Once stabilized we re-tracked a scaled version back into the shot.
Since the original baby was covering a larger area of the frame, the background had to be meticulously reconstructed. This included rebuilding the faces of the other actors in the scene. This was accomplished by pulling frames from later in the shot where the faces were not obscured. Then re-sequencing them to approximate the earlier face positions. Then multi-stage morphing the frames together in their new order to create in-between frames that could be composited back over the obscured faces.
After rebuilding the faces, the actor's bodies, the car, and the rest of the background had to be painted in as well to erode the edges of the original baby from the scene.
Once the clean plate was constructed the smaller, stabilized, and re-tracked baby we introduced into the scene. Careful attention had to be paid to the center of gravity of the baby as he was handed from actor to actor, and then slid down the hip of the actress at the end. Both actors hands had to be meticulously rotoscoped as well to place the fingers back over the smaller child.
This is the completed shot from the film with the smaller baby.
Here's a side by side comparison of the two baby sizes.