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Cutting off limbs in CompositeLab
This tutorial will cover the basics for creating the illusion of limbs (amongst other things) being cut off. It can be used for a viarity of wanted effects, like chopping a head off, ripping an arm out or just simply making something fly. It's up to you! But in this example we'll cover how to cut of a head.
You'll need to shoot the shot this way:
- Lock the camera
- Start capturing, and let the actor(s) preform their part
- Without moving the camera (it's usually best to not touch it at all) start capturing again, but without the actors. This will create a clean backgroundplate for you to use in the compositing of the shot.
This is my original footage that I'll use as example in this tutorial.
Now, to begin with you open up a new project and select the proper settings. Import the video clip, and part it up into two pieces, two seperate tracks. On the bottom track you place the background-shot without the actor who's going to have his\her head chopped off. Over that you place the part where the actor does his\her part and falls down or whatever. Make those two tracks end at the same time and set the out point. (O)
Now you look through the timeline. Find the moment where the actor is supposed to get his\her head cut off. Study the movement carefully and choose an excact frame where the compositing should begin, and the head are starting to leave the neck. ( )
At that excact frame you create a new mask, and make it so that it seperates the neck from the head and covers roughly the head. Already now you might be surprised of how cool it actually looks!
The following is a bit timeconsuming, because now you have to animate the mask throughout the rest of the shot so that it coveres the head. Remember to have the line that seperates the neck properly placed through the whole act. As you can see I've not animated every single frame, but because of CompositeLab's excellent tweaning system the mask follows its motion smoothly.
By now the shot should already look quite impressive, as the head will suddenly disappear and the actor will continue his\her acting to the end of the shot with no head. But it's not finished yet! Now we have to have the head itself being chopped off and fall down to the ground. To do this we need to have another track, a copy of the current upper track. This is done by a simple Copy-And-Paste to the left of the timeline.
Now that you have two identical tracks, crop the new track so that it starts of at the frame where the actor looses his\her head. You won't notice any differense yet.
We want the head to be visible all the way untill it falls out of frame, so you delete the mask. Do not delete the mask in the track below! Only in the upper track!
Instead of the mask you create a new garbage matte which will keep the head as the masked object nomatter how you animate the shot. The Garbage Matte is found under the "Matte" submenu. Now carefully draw the garbage matte around the head. You might also want to add a slight feather to the mask. (Don't worry, the head will be a bit blurry anyway when finished if you're using Compositelab Pro or VisionLab HD) Animate the garbage matte so that it follows the heads excact movements. Choose a length of the head-animation and animate it all the way to that frame where you crop the shot to end.
Now this is the fantastic thing about this: now that you've seperated the head from the rest of the image you're free to animate the head just as you want! So, animate the head so that it looks like it's being cut off the way you want to. I made it fly a bit up into the air, spin around slightly and then fall down to the ground. I also made a little after-jump to increase the realism.
Through the whole animation it's quite cool to add a rotation of the head, so play around with the rotation-wheel. Unless the actors head is in the center of the frame it's best to do the rotation at the same time as the quad-manipulation. Making the animation seem believable might be a difficult task, so play around with it until you're happy about the animation.
The effect is now complete! The basic part of how to make the illusion of a head being cut off is now done..! Congratulations!
CompositeLab Pro and VisionLab HD users!
Owners of CompositeLab Pro and VisionLab HD will in addition be able to add motion blur to this effect.
Click on the "Grade" button to have the toolbox show the different grading options. Select the "blur : angle" and give the head-animation a bit motion blur while moving. NOTE! The rotation-wheel will not apply correctly to the finished result because you've rotated the whole clip, so keep an eye on the complete project while doing the motion blur.
And that's it!
Take a look at the finished shot here!
Now you can use this for whatever you want, lightsabre stunts to brutal gunfights. You might also want to add some blood-effects to the incident. I hope this has been an interesting tutorial, and that you're happy about your result!