Transforming Robot Production Pipeline Volume 10: Compositing

In this lesson, we're just going to take a brief look in Maya at how we set up the nodes and exported them to FBX to begin our particle work in Nuke. Now to begin with, I've rearranged the project files just a little bit. So if you go into your project files, you'll find in Nuke Scripts I've put all of the finished scripts inside of this folder. And that's just because we have, as you can see, quite a few of them. So I've just opened up Truck Particles Version 5, and this is where we're going to start with our particle work. So as you open this up in Nuke, we'll start at the top obviously. And we have two FBX files that we are importing from Maya, and these are the wheels of our truck. So if you hit Tab to jump into your 3D view, you may want to actually disable your particle emitters just to speed up your workflow and your view port. Not sure what kind of a computer you're working on, but I've noticed that particles can sometimes freeze, pause, or otherwise slow down my pipeline. So if I'm not actively developing them, I always disable the emitters so everything's nice and snappy. So if we take a look at our transformed geometries and take a look at our wheel emitters, we can see these pieces of geometry, and if we click the TransformGeo, the exact emitting location of these pieces of geometry. Now these were exported actually from Maya for use in Nuke. So let's jump over to Maya and quickly see how we exported these so in the next lesson we can begin talking about our particle set-up. So I've jumped over to Maya, and you'll find this file inside of Maya Files, Wheel_locators. And this is just a stripped down version of the file that the rigging artist gave to me, or the finished animation file that was sent down. And to create these emitting pieces of geometry, I just followed a few simple steps on every single tire. To begin with, I created a new locator. And then Geometry constrained it to the ground, and then Point constrained it to the tire geometry. And what that gives us, is it gives us a locator wherever the tire is actually touching the ground geometry. And it's going to stick to the ground wherever it is and so this is a great way to get the position information of where our tires are, in respect to the ground. Now from there it was a rather simple process of creating a new piece of geometry. I've left the history intact if you want to take a look at this, I believe, on one of these. Essentially it was just a cylinder that we created. We just cut it in half, added a few edge loops, and there we go. So as you can see, it's an incredibly simple shape. And I've just parent constrained this to our locators and moved them back just a little bit. And rescaled them, or moved the points so that they are essentially in the area where dust would begin to be emitted. Now the track of this, or essentially the location and the movement, is not perfect. As the tire moves up, you can see our emitter geometry is left behind as it is stuck to the ground. But this is going to give a rough estimate that we can refine inside of Nuke for the position where our dust should be emitted from. And since we're emitting this dust mostly pretty far away from the camera, I'm not too worried about inner-penetration or small shifting issues that we might see. So with all that done I just select all the emitters, of course. Gone to File, Export Selection, FBX File, I'll check here-- looks like I don't have that loaded. So, of course, Windows, Settings Preferences, Plugin Manager, FBX Export and export that out into the FBX file format so that Nuke can read it in. The only change I made is obviously to bake these animations down so that we have the key frames available. And I'm using the FBX 2010 as it is the latest FBX, I believe, that works with Nuke. But, of course, with newer updates and newer software, we might be able to use newer versions of the FBX file format. So that's essentially all we did in Maya. Beyond that, I believe we actually also took a look at the center of gravity controller for this entire truck. Let's see if that's still around. And we connected another piece of geometry to this position so that we could have this information available to us in Nuke. Finally, we took the ground geometry and exported that out as an FBX as well so that we would have something for our particles to intersect and so we had an idea of where the ground plane should be. So if you jump back to Nuke, we can see here are the six tires we brought in and four of them we really didn't use. For this drop-in, just read Geo Node, read this in, duplicate it across and change the node name emitter. So here we have the front right wheel ground and the front left wheel ground. So after that was done, we brought in the ground. And now we can take a look at how we set up our particle system to create a dust cloud trailing behind our transforming robot in its truck state. So we'll begin breaking this Nuke script down in the next lesson. So in this lesson we just took a quick look at how we exported all of our data from Maya. And this may or may not be your responsibility as a compositer. If you know that you're going to need to create particles from various pieces of geometry, you can of course ask for these locators, these positions, these animations from the 3D department. But if you're lucky enough to be able to use 3D software and Nuke, you'll be in a much better state to create the tools and generate the tools that you need in Nuke inside of Maya, and then use the FBX format to cross-pollinate.