The Halo 4 greenscreen is a fantastically powerful tool for machinimators, but from everything I have seen so far, no one has used the green screen right. I realise the majority are tests or first timers, but to place a Halo character, vehicle, Forge building block into another world there is one thing you have to do. Think.
Almost every video created to show off the green screen use, uses inadequate footage, for example, the Halo footage composited into another game or the real world has a constantly moving camera (recorded from theatre mode or live action). Without propper planning this will never work, especially with static images found on the internet.
Another issue, is the complete lack of planning in terms of camera position. Before you go into Halo and shoot your green screen footage, find the location or image you will be compositing onto and considering this when planning your movement in-game, and your camera positioning in theatre mode.
This below example, almost gets this right, but at times falls short:
Also take into account, you can angle green screen pieces just like another in Forge, use this to create a layout similar to that you are planing to superimpose onto.
As you can see, planning is imperative. The video at the top of this article was created by myself in response to all the bad green screen use. It is in noway perfect, but every shot (except the Spartan to camera) was planned out and researched before capture.
The warthog spawns on ground that is shot from a similar angle, character select Spartan is similarly sized to the other Minecraft skins, and most importantly, when the camera does move in both worlds it has been planned. When the Warthog drives across the grassy plain, the camera positioning in Minecraft was thought through in terms of what can be done in Halo 4 theatre and the same can be said with the Banshee flying.
Also take into account the onscreen assets, if you have the ability to chroma-key you will guaranteed have the ability to mask or reframe assets on your timeline. If something doesn’t look right, don’t just leave it wrong- Fix it.
The camera pan up on my Warthog spawn turned out completely different to the motion I captured in Minecraft, but I persevered. I altered the speed of the Halo footage to match what was captured in Minecraft, moved the Halo footage down in the frame so that it matched exactly. Unfortunatley this meant in the pan up in Halo I was left with an area of the warthog cut off (until the camera caught up and revealed the entire vehicle) to fix this i masked the top of the Warthog, added some feathering, and as the full Warthog comes into view, moved the mask upwards to reveal the top. Mixed with a few simple VFX, a small bounce in motion, it still added up to a somewhat believable Warthog in Minecraft Spawn.
The above video actually works pretty well and takes into account the environment and camera positioning. The only issue is the quality of the chroma-key itself, I would recommend using Adobe After Effects with the usually pre-installed plug-in Keylight - also a few shadows added in would help too (see top video under the warthog on spawn).
I really want to see the Halo 4 Green Screen used for fantastic things, and I release this may seem more like a rant than a tutorial, but with such a powerful tool, to me it deserves better implementation in videos. I will be using it again soon, I have several big ideas for Gamer UK exclusives, and I hope you will all take into account everything I have said and use it too.
For more information on the process of chromakey and how to use the programs needed to use the green screen successfully, this video created by Caboozal is a great start.