Compositing a VFX shot using Nuke and ProductionCrate

We chat with three Nuke compositing students to discuss their course work, what challenges they faced along the way, and how they integrated ProductionCrate’s original assets into their VFX shots to create unique scenes worthy of their portfolios!

As part of CG Spectrum’s Nuke Compositing Course, students are tasked with integrating CG, matte paintings, library FX assets, and live-action footage to create a seamless, single-shot — an integral part of a professional compositor’s role in the industry. 

To help create their VFX shot, CG Spectrum students have access to thousands of high-quality assets from ProductionCrate's VFX and motion elements website, FootageCrate, which is included in the course fee.

A still from ProductionCrate with added smoke plumes and fire, demonstrating just a couple of the thousands of original VFX assets available for download and use

CG Spectrum's Dept. Head of Compositing, Sean Amlaner (Black Panther, Shrek, and Bridgerton) explains the importance of having access to quality library assets in film and television:

While plenty of customization happens in the VFX pipeline, allowing for all categories of VFX job titles to play a critical part, library FX assets play an invaluable role in the overall post-production visual effects industry.

What are production library FX assets?

Production library FX assets cover many different categories: fire, smoke, floating embers, explosions, bullet hits, squib (blood) splatter, basic-rendered vehicle elements, water pouring, water splashing, magic-based FX, and much more!

Library FX assets can make for very convincing and realistic effects-based compositing if done properly, and there are some major advantages to using pre-created elements. They can save a significant amount of time and resources because the only department in the entire VFX pipeline it needs to go through is compositing. Library assets are a quicker, cheaper, and more resource-friendly method, particularly for episodic streaming media. 

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More customized FX elements, however, will require input from the VFX pipeline. These projects typically cover some of the larger-budget categories of feature films and episodic streaming media.

What to look for when selecting library FX assets

According to Sean, there are many things you need to look for in a good library asset. Below are some of the questions you should ask when making your selection:

• Variance — Multiple versions of a ‘type’ of asset are great for building up a scene. For example, how do we make a building look like it is burning but not have repeating fire movement?
• Element resolution — Is the asset a large-enough resolution? Can you zoom in and isolate a specific area of that FX element to use?
• Perspective — Does the asset match the perspective of the background plate and, if not, can it be digitally modified inside the compositing software to properly match?
• Element movement/speed — Does the movement of the element match the movement of the background plate? For example, if adding a CG vehicle driving across the horizon, does it match the movement/speed of a live-action car that might also be in that scene?
• Motion blur — Does the asset have motion blur or will that need to be added in-comp? If already rendered, will it match any motion blur of live-action elements in the background plate? If adding in-comp, will we be able to replicate the motion blur referenced in the live-action background plate?

How to use VFX elements

Recent Nuke compositing students put their skills and their FootageCrate assets to the test, compositing landscape drone footage with "explosive" results! Check out their work and read their processes below.

Laura Whitty 
For my project, I chose to go down the “end of the world” route. I wanted to go with something that looks simple enough, but in order for it to feel as close to real as it could be, I'd have to work hard. 

Everything in the shot that isn’t the main video is from FootageCrate, which includes the main and background asteroids, the smoke plume, the explosion, the shockwave, and the breaking ground. Even the flash of light is a lens effect taken from them. 

Laura's final version. She used a wide range of FootageCrate assets to help build her scene: from large and small asteroids and the shockwave to smoke plumes, explosions, breaking ground, and even the flash of light lens effect. 

Getting the asteroid to hit and make it look real was a challenge in itself, with the lighting on the plate needing to be as realistic as possible, and matching the colors, adding subtle things to finish it off and give it that cinema feel. 

The most challenging part was the cloud of dust heading towards the screen, to get it to roll over the hills, and be in time but not look like a direct copy of itself. There were a lot of things that on paper should’ve worked to help accomplish it, but, frustratingly, didn’t. For me it’s not 100 percent perfect, I still see elements that need adjusting but that’s the same with anything creative. 

I learned that I can proceed with an edit from scratch by myself; I can create a shot from start to finish with no help on what I need to input, which is something I thought I wouldn’t be able to do.

Shot breakdown of Laura's final composite, demonstrating all the work, layers, and FX library assets from FootageCrate that went into making her shot. See more on Laura's ArtStation.

Joe Carvalko
Upon being presented with various footage, I first liked the aspect of the camera move on the shot I chose (just to make it a bit more challenging for myself). I’m probably like any other student in compositing where we just want to blow stuff up, set things on fire, make scary stuff, and alien worlds. So, I looked at the footage piece I selected and decided, “It’s a nice place…it really needs some destruction to go with it!” 

I wanted some explosions that would wake the neighbors in the shot, so my first task was to look at reference. Reference is king. I looked at as many different types of explosions available through FootageCrate as possible. Knowing that different munitions created different signatures, as well as the intended targets, I had to look for footage to fit my style of targets. Looking at the timing of the blasts and smoke was critical. 

Along with the initial explosions, I realized I would also need primary and secondary smoke assets along with a third level of smoke. I used various explosive assets from FootageCrate. 

I wanted each one to be different, including smoke and dust assets, debris, and still assets such as scorch marks and building damage that would reflect the aftermath of the explosion to the structure.

This project taught me that details matter. The viewer may not directly notice some aspects, like the sparks from the transformers on the poles, but it makes a difference. 

My biggest challenge was tracking certain items. So if I couldn’t do it in Mocha, I ended up using Nuke’s tracker to do it. 

The other challenge was deciding what to blow up and how much was too much. I thought one missile would leave a lot on the table, but 20 missiles would be overkill. So I settled on four and spaced them out as if someone was targeting the area, not just one certain building, and I also decided one stray hit would be expected. I also decided to change out the sky to make it a bit more foreboding.

Joe's outstanding final shot. Explosions, smoke, dust, debris, scorch marks, and building damage from FootageCrate. Check out more of Joe's work on his impressive compositing showreel.

Next time, I’d probably add more debris flying into the air from the blasts and maybe add some CG cars getting lifted from the blasts.

Ben Macchiano
I know driving comps and paintouts are a big part of what junior compositors are expected to do, so I thought having a keyed-out pilot and landscape with electric poles painted out would be a good idea. We decided that the general narrative would be to have an aerial pilot ascending in a ship while witnessing a bombardment of a city. Using assets and footage from FootageCrate, I tracked on forcefields, smoke, fire, and helicopters. 

Ben’s final shot as part of the Nuke Compositing Course. HUD, smoke, helicopters, forcefield, and most of the fire is from FootageCrate — a total of 13 elements. Other elements (two fire elements that are action VFX and the cockpit footage) are from YouTube.

I learned that timing can be a challenge in Nuke! It’s best to map out the timing of your elements and plates at the start, if at all possible. The drone footage was relatively long and slow for the purpose of the shot. So we retimed it, but once you change the timing, any tracks or roto must also be revisited and reworked to match. 

It turns out that being thorough and patient are key traits in compositing!

Using the assets from FootageCrate, my mentor also showed me a few techniques for blending fire with smoke, which is not the most intuitive thing — one is rarely smack-on top of the other; it requires a kind of finessing to sell it.

Breakdown of Ben's final shot, demonstrating all the layers and FX library assets from FootageCrate added as part of his process.

[Ed note:] Ben used some of the excellent work he created while studying at CG Spectrum in his compositing showreel and guess what? He landed a job this week at Artjail in New York! Congratulations, Ben, we can't wait to see what you do next.

Skilled VFX compositors are in demand! 

Did you know that even if a shot doesn't need to go through any other VFX department, it will most often go through compositing? This makes compositing an in-demand position in the visual effects industry.

Whether you're a beginner or more advanced, CG Spectrum's Nuke compositing courses will provide you with specialized training to help you progress in the visual effects industry. Learn how to layer live-action shots with CG and library FX so seamlessly you'll have people thinking it was all filmed in-camera!

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