(Sorry I’m not someone who does composite work at all so this may be common knowledge)
I thought of a way of color keying this morning that I wondered if anyone has tried in Blender or at all.
Not really sure how to explain this
Shot 1: Person in front of green screen (Only used to extract color information)
Shot 2: Same person in the same cloths in an environment where it would be impossible to green screen like a person running in the woods.
Could you setup a simple keying shot where you can control what object is to be keyed(a person) on a green screen which is shot 1. Take that shot, separate the object from the background and then uses the color information about the object in that shot 1 and use that to mask out that object in shot 2 assuming that nothing else shares the colors found on that object in the environment of shot 2.
Does this make sense? Is this possible with blender without programming at all? Is this a common technique that I’ve just never heard of? Do you think this would work?
I don’t know if it’s possible, but you’d have lots of problems if it was. The main reason for problems is that you would need to have the exact same lighting & environment setup to get the colours the same between shot.
Even if you had the colors exactly the same the program would probably would select the colors in the environment that where similar to that of the clothing.
Challenge: Seperate running person from forest background.
Issues: 1. Person running has some blur causing indistinct edges for key. 2. Person running may have similar colours or shading to background making seperation hard. 3. Shooting person on green screen wont help as lighting must match forest exactly. And you can just sample the actual colours from the forest footage anyway. 4. What will you replace the person shaped hole with? As the background is obscured by running person.
Solutions: Seperate subject from background, light (with colour) the background very differently to the person running. ie. if the forest is mostly green the light the person red and key them out. Or shoot the scene 3D and use depth information to remove the foreground element.