To create something as instantly familiar and recognizable as a time-lapse sequence, reference is absolutely essential. Start by taking your own photographs and investing a good amount of time researching the Internet for images and videos.

For this project, "Carbon Footprint," we would wander about the streets of London on our lunch break looking at dirt, stains, litter and corrosion and taking macro photographs of what we found! This can be a very exciting time in the development of a project, when you lock down the elements that you’ll be recreating or images that are a source of ideas and inspiration.

I was taught many years ago by photographer Andy Hughes (www.andyhughes.net) and I found his photographs of litter to be a great source of reference.

"Carbon Footprint" changed dramatically from the first animatics that were created. Usually and ideally, this shouldn’t happen. But in this case, it further illustrated how essential an animatic sequence can be. There were many shots and cuts in the early versions that made us realize it would look better and more impressive as a single seamless shot. By creating an animatic, you and your client can see a rough draft of the entire sequence. This leads to a lot of creative discussions, revisions, notes and, often, new ideas.

Once we got this assignment, we invested a considerable amount of time in R&D. If you want it to rain one moment, snow the next— all the while grass grows and paint erodes— you will need to figure out the best way to achieve your idea. The inevitable problems and challenges may arise when working on your visual effects. The best way to solve them is to have solved them already! Spend some time thinking and trying out how you will create your effects— it can save you hours of headaches later in production. One last bit of advice during this phase: Try to create things with the skills and knowledge you already have, and don’t be tempted to jump into the deep end with a new piece of software or fresh script to write.

If you’re creating a visual effect, chances are you’re matching something to a real-life location. Taking further reference photographs and images to use as textures later on means you can accurately recreate a piece of the real location. An HDRI lightprobe is an essential addition to your toolkit. By capturing the real lighting data from the set, you can quickly and accurately recreate lighting and reflections later on. Creating your own means you’ll have an exact match of the location you’re in and also something that’s unique.

Modeling can be both frustrating and enjoyable. Having your reference images on hand means you’ll be able to build accurate shapes and forms. You might have a modeler or modeling team build your assets for you, or maybe you already have models suited to your project. 3ds Max has some great poly modeling tools that let me quickly create all the objects I need. It’s essential to keep your models as neat and tidy as possible; also make sure they’re all quads (four-sided polygons). This will help you avoid problems later when you try to deform and render them. It will also speed the process of creating UV maps so you can accurately apply textures.

As you start to consider your textures, open up all your reference images from earlier and start to sift through what you think you can use. If you’re creating an object you can buy, such as a soda can, then head down to the corner store and grab yourself a well-earned can of soda so you can have the real thing on your desk to study.

Use your preferred image manipulation software to patch together the required texture maps, taking care to align them all to your neatly laid out UVs. Frequently test them out with the shader you’re using and on the object. Your R&D from earlier might come in handy here, as metals are quite complex materials with various levels of reflectivity and density.

You or your studio probably have a preferred rendering engine, and a number are available for each 3D application. For "Carbon Footprint" I used the GI engine in SplutterFish’s Brazil r/s render system for 3ds Max. By using the HDRI you made earlier, you can quickly light your scene and align accurate reflections. Rendering can be a hugely time-consuming process and part of your skill as a 3D artist is being able to balance quality with time. Other time-saving techniques include baking lighting to textures or projection mapping. I used projection mapping extensively on this project, from rendering a few huge 8k images of the scene and "projecting" them back onto the scene geometry. We’ve found that this can sometimes save days of render time and will look indistinguishable from something that took three days to render.

It’s commonplace to use "passes" when rendering so you can have complete control of your rendered image later on. By splitting your render into what are essentially split elements, you or your compositer can blur or sharpen reflections and shadows, tint shadows, change colors and even relight 3D objects. Due to time constraints and the sheer amount of data we were creating for "Carbon Footprint," render passes were kept to a minimum: all we did was a main beauty pass, then reflection and depth passes.

Compositing is an essential and incredibly powerful stage of the visual effects process that can can greatly enhance your rendered scenes. We composited "Carbon Footprint" in 3D space with Digital Fusion to be able to import 3D scenes from 3ds Max. This let us insert further details and debris accurately behind and around the soda can, without any need for mattes or roto work (a huge time-saving trick).

The final step is a more creative and less headache-inducing stage where you can color- grade and tweak your sequence to perfection. Much of the time-lapse/sequenced photographs effect for "Carbon Footprint" was done in post by offsetting frames, adding macro-lens distortion, saturating and de-saturating colors and animating gamma levels. Now you can go and watch it on a giant television screen and marvel at your digital creation… and notice a few mistakes that you missed!

Tools Used: 3ds Max, Softimage|XSI, Pixologic ZBrush, eyeon Digital Fusion, SplutterFish Brazil r/s, glu3D

Matt Chandler is a TD and lead visual effects artist at Jellyfish Pictures, an award-winning visual effects studio based in central London. He was VFX supervisor on the award-winning "Carbon Footprint" short that was first broadcast on Discovery Channel EMEA (Europe, Middle East and Africa). He was also a lead TD on the multi-award-winning BBC series Fight for Life, generally recognised as representing a step change in internal human body CGI realism.

MATT SAYS KEEP IN MIND…

Remember to sleep and eat when in the middle of a busy and time-consuming project! If you’re tired and struggling to solve a problem into the early hours, you are going to be even more tired and unproductive the following day. Getting a few hours of rest will mean you’re refreshed and able to tackle them anew.

To view the final video, go to Jellyfish’s Web site here and click on "Visual Effects." Click on "Carbon Footprint" image in the upper right-hand corner.