next week I have a challenge in a shooting. we are recording a videoclip and the director want to create a VFX on the face of the singer, erasing his nose , eyes and mouth, and including some burn paper effect composited in his face.
My first idea was covering the face artist with green tape, in order to track in mocha y later doing a chroma of this part and changing for this burn paper effect.
As well, I was thinking different ways how to develop this effect. I was thinking recording burning papers to blend with some of the fires tutorials in after effect. Or should I try to do this burn effect in cinema 4d with some of the particules???
Mocha does not track green or flat colors. Mocha tracks textures and shapes. The outline of a green marker may possibly be tracked but the nose, mouth and eyes are natural track markers on their own and will offer much more tracking information for Mocha.
As for painting out the mouth, nose and eyes, it is best to paint them out to create a clean plate before overlaying with the burnt effect. To paint over the existing facial features, you will need source from which to clone.
Taking closeups of the face will allow you more source material from which to clone, relative to cloning from areas within the same shot that will be tracked. You should shoot the closeup material with different perspectives to allow you more options for your clone material.
Such effects are not difficult if the perspective change isn't too drastic. Suggest to the director to take at least one safety shot for each take with the safety shot having less perspective change.
thanks a lot too Roland. In theory, we want for the face basically to blur the nose, eyes and mouth. It is kind a effect similar to Sunshine for the spotless mind, where there is a frame where the doctor has the face blurred with Skin.
so I guess we do not need to clone the mouth, eyes and nose. Which it could be interesting filing that part with skin texture, maybe in 3d.
Later over this skin including this burning paper effect.
One of my friends recommended me to create small circles of green around the silhouette of the face I will blur. so using this green point I can track with mocha and including on here this composition with the skin and burning effect.
[Victor Camacho Guerrero]"so I guess we do not need to clone the mouth, eyes and nose. Which it could be interesting filing that part with skin texture, maybe in 3d."
You do not need 3D for this. Since Mocha is going to give you a perspective track for each of the different facial features, all you need is a clean patch, one for each of the facial features. Then apply the appropriate Mocha Corner Pin data to the patch for the corresponding facial feature.
[Victor Camacho Guerrero]"Later over this skin including this burning paper effect."
The burning paper effect is applied with the same technique for applying the patch.
As for the silhouette, does this mean that you will shoot twice, once with a silhouette and another without? Do, yeah, I think I'm not following you. As I've mentioned, the facial features are already natural tracker markers.
When in doubt, ask the COW then as always, do a couple of test shots before the actual shoot.
This was what I had in mind too. As I've mentioned tracking the facial features without any markers should be sufficient.
You may of course place markers BUT these markers should supplement the natural tracking data AND NOT obscure the natural markers. How large these markers are and where you place them are crucial.
If it were me, I'd place high contrast stickers - even cartoon ones above and below the lips, on the side's of the bridge of the nose, above the eye-brows, and the sides of the temple.
Again, run a couple of tests to see which works well.
Once you have the tracking data. The trick is to then create a clean plate which you will then apply the tracked data. As I suggested earlier, various closeups will come in handy as they will provide you with sufficient clean areas from which to use as clone material.