11.) Now do another Paste Linked of the Master Fade node and attach that under the screen node you just make. Your tree should now look something like this:
12.) Now we can go and screen these two elements together giving you a tree that looks like that:
This tree should give you an image that looks like this. You can now use an Add or Screen node to composite this over your plate that you shot and color correct to taste.
Using this technique of a Master Fade node gives you the ability to control many elements by animating only 1 node.
Extra Credit
So now you know how to create a muzzle flash without ever firing a gun. The one thing that is missing is having the background react to the light given off by the fire. There are many ways to do this, so since this is more of a beginner tutorial, I’ll go with something a little easier to do.
1. Take your BG or FG plate that needs to be adjust and attach a Lumakey node. Turn on the matteMult radio button in the parameters. Adjust the values so that only the highlights are visible. If you need help using the LumaKey node, refer to the user manual for more info.
2. Blur the resulting image and use an IAdd or Screen node to comp it back over your existing plate. 3. Now take another Master Fade node and Paste Linked (shift+apple+v) and insert that under the blur node to control the opacity so that it is only visible when the flash fires. Your tree should look like this:
One thing that I wanted to point out here are the noodles that connect the nodes to each other. As you can see, the ones coming off of the Muzzle Flash are 8 bit and the rest of the comp is 16 bit. You can tell this by how the lines are broken up. The 16 bit lines have bigger spaces whereas the 8 bit spaces are very small. This is an excellent feature in Shake that lets you determine the bit depth of your elements at a glance. If this was going to be a real comp to use in production, you want everything to be the same bit depth, or at least the highest bit depth in the comp. What’s nice about this example is that if you were creating the element in 8 bit space, and then you realized that the comp should be 16 bit, all you have to go up to the Rotoshape node and change the bit depth to 16-bit.
You can also tidy up your script by putting things into groups which helps you and others decipher what is what. You should also name all of your nodes just like I have not done here.
Shake is a very robust tool indeed. In my opinion it is a great app not only for what it can do, but because it forces you to actually understand compositing, so that you know what is going on underneath the hood. You can then take those fundamental principles and apply that to any app or image you wish. So instead of wondering where the "Stencil Alpha" button is and what that really does internally, you'll know that all you have to do is multiply away the unneeded parts of the image. Compositing is essentially all pixel math, so if you know what the operations do mathematically, your life as a compositor will be that much easier. Nodes may seem a little daunting at first...especially if you have been using other packages for a while, but once it clicks......everything clicks. So learning other node-based packages will suddenly become much easier.
Another good skill to have is knowing how to build nodes that don't exist, such as a glow. I did cheat in this tutorial by using a plugin, but you can easily build your own glow with just a few nodes as I did with the BG layer at the end of the tutorial. Take it upon yourself to try and build some of these for yourself. Not only will you save time later on down the road, but you will teach yourself how these nodes work internally. So if your package does not have a particular node, you can now look like a hero when you build it from scratch.
Happy Shakin’,
Sean Falcon
Gaining national acclaim for his work as the Visual Effects Supervisor on Alex Ferrari's Broken, Sean Falconnow works as a Shake Compositor for Sony Playstation Studios in San Diego. For more on what he's up to, check out his site at: http://www.seanfalcon.com.
