Making of 'Tough Love'

Introduction

At Slide Ltd we have a great rule: between every few paying jobs we undertake an internal studio project, in order to experiment, explore and expand without putting our clients at risk.

Our explorations for a recent project were twofold. Firstly this piece was to be a principle production illustration that would establish an art direction for an 'imagined' larger production. For this we wanted to try to create an oppressive mood, with light, shadow and detail pressing in on the characters while they stand in a 'defiantly relaxed' pose.

The second purpose was to give us a test project that would allow us to amalgamate all the new processes and techniques we've learnt over the past 18 months into a new, internal 'best practice' pipeline. As we're an illustration and animation studio this all had to be done in an animation friendly way.

This 'Making Of' article gives us the opportunity to share our results with the CG community - we hope this is both useful and enjoyable! To see more of our work, or to get in touch, please visit our website at http://slidelondon.com.

Concept Development

Partly inspired by the current economic turmoil, we decided to paint the portrait of a couple who have descended into criminality against the backdrop of a once prosperous, consumer-driven European country - in some ways echoing Bonnie and Clyde and their spiral into notoriety during the Great Depression of the 30s.

How would a relationship manifest in such a harsh environment, where the comforts of modern life are not there to ease the process of maintaining a loving relationship? Would couples instead be bound by a more visceral form of co-dependency?

Our first step was to gather references and create some preliminary concept and design sketches (Fig.01 - 02). This was more about a first pass at the details of their costumes than a fully polished concept piece.

d_Fig.

d_Fig.

d_Fig.

d_Fig.

Compositionally, we started off playing with the idea of a torn dark heart (Fig.03), conveying the cynical and slightly twisted relationship between the two characters and hinting at the environment's role in making them that way. In the early stages we jumped between 2D paintings and 3D block-outs to explore our ideas, using whichever medium was quickest at getting an idea across so as not to stagger the process.

Fig. 02 d_Fig.

Fig. 02 d_Fig.

We ended up with plenty of fun ideas we would love to follow up - including a possible three-panel strip (Fig.04) telling the story of a typical day in the hood. With this conceptual framework in place, we were ready to dive in and start working up the piece.

Fig. 03 d_Fig.

Fig. 03 d_Fig.

Characters

We have a robust pipeline for producing 3D characters at Slide, in many ways that is our speciality. We tend to start out with a quick concept sketch, just nailing basic forms and direction. We then try to get into a sculpting package as quickly as possible, continuing the design process by painting over screen grabs out of ZBrush or Mudbox (Fig.05).

Fig. 04 d_Fig.

Fig. 04 d_Fig.

This is an iterative process, we create the paintovers then jump back into our sculpting tool to propagate any designs or ideas generated by the paintover into 3D, further refining the design and sculpt as we progress. Our reason for this is simply to be sure that our design isn't relying too heavily on 2D 'tricks' in order to work. In our experience, working at a range of studios on projects ranging from games to TV production there is always a fair amount of 'redesign' needed during the 3D phase, we simply find it more controlled and productive to treat the concepting phase as a combined 2D/3D task. This way we get the benefits of quick paintovers in 2D, while proving out that the design works in 3D using rapid sculpting.

The end result of this process is a roughly textured, full 3D character maquette (Fig.06) which is then ready to be translated into a production model with final textures and shaders.

If the character is for hi-res use (such as in this instance) we will create mid res subdiv. mesh ready for use with displacement and bump maps. If the characters target is a realtime engine then we produce a mesh with a suitable level of detail for the intended engine/project specifications ready for normal/bump maps (Fig.07).

d_Fig.

d_Fig.

d_Fig.

d_Fig.

Environment

After playing around with a variety of compositions, we settled on a close crop of our protagonists against their natural environment. This gave us lots of scope for background detail while still making the piece achievable in the time we had allotted for this internal project.

We dug around in our reference library to explore a gritty, distressed urban fabric, and the bright graphic elements with which a faded consumer society would once have adorned this environment (Fig.08). Graffiti, posters, tags, filth and fury ... delightful!

Fig. 07 d_Fig.

Fig. 07 d_Fig.

We initially white-boxed the scene in 3ds Max using placeholder objects to establish camera and object placement. When a direction became clear, we were in a good position to take the basic geometry a step or two further before using it as a basis for reassembling the scene in ZBrush.

We've had a lot of success using sculpted 'digital maquettes' for character development: the immediate visual feedback and short iteration times mean this method is a great way to start injecting detail and mood at an early stage. This project was the perfect opportunity to expand this process for environment assets (Fig.09).

Fig. 08 _Fig.

Fig. 08 _Fig.

As our models progressed, we made much use of ZBrush's ability to work on low subdivision levels externally and re-apply high level detail. Non-destructive tweaks to underlying topology and UV-maps are essential when preparing sculpts for clean texture extraction and practical use in renders.

We brought meshes back into 3ds Max (via the .obj file format) at a variety of resolutions, baking out bump and displacement maps for the more visually important elements.

Displacement maps in Mental Ray almost need a whole 'Making Of' to themselves! Establishing a robust workflow was far from trivial, so here are some pointers for anyone else attempting this:

  • Retopologise and re-UV your underlying meshes before baking. A good, clean mesh with roughly equal quads and clean UVs is the key to getting a good bake.
  • Use Mudbox to bake. A bit cheeky perhaps, but in our experience - compared to ZBrush 3.1 - Mudbox 2009 is quicker, more reliable and easier to tweak to get good maps. Your mileage may of course vary.
  • Use 16-bit displacement maps. Displacement should ideally be stored as 32-bit floating point textures, which store actual world unit offsets. In practice, we couldn't get Mental Ray to use these in a remotely stable way - most of our renders either crashed or had crazy artefacts (Fig.10 - 11).

_Fig.

_Fig.

_Fig.

_Fig.

  • Use material displacement rather than the Displace modifier. The former optimises what it does based on the screen-space size of the displaced object; the latter requires modifier-based mesh subdivision which will eat up all your memory before you get to a decent poly resolution - especially if you're displacing many objects in a scene. Of course, depending on the density of your low-res mesh you may need to meshsmooth it a little - do this within the NURMS section of the Editable Poly.
  • Worry lots about gamma. Displacement textures represent distances and as such should not have gamma or colour correction applied at any point. Opening, editing and converting them in Photoshop can do this if you have colour profiles enabled. 3ds Max and Mental Ray have numerous sneaky ways of doing this behind your back - be it through the overall app. preferences, the bitmap material node, the Mental Ray map manager and so on.
  • Test out your maps as you make them. As you start to establish your displacement pipeline, produce comparison renders of your displaced meshes against their high-res sources. It's often the case that the whole mesh will have receded or bloated (particularly with gamma issues) and laying one on top of the other is the best way of spotting these problems.
  • When it comes to shaders we use whatever tricks and techniques we know to produce a good result, and then optimise the network and its textures to keep both the scene and render times manageable. In this case, textures were created from a combination of photographs and hand-drawn elements, layered with baked cavity maps and a lot of good old-fashioned grunge (Fig.12 - unfinished and unlit).

Fig. 10 _Fig.

Fig. 10 _Fig.

In addition to 3ds Max, we use a variety of tools for UV mapping and shader development. For more detail on these have a look at our tools page: http://slidelondon.com/iv.

The result was a rich and stylised setting for our scene, full of juicy detail but light enough for easy manipulation and quick renders. From here we moved onto lighting.

Lighting & Rendering

When it came to lighting this scene we wanted to concentrate on achieving an evocative and expressive feel using a simple Mental Ray Sun + Sky setup (with light portals, left), rather than a traditional point/spot rig.

While we anticipated slightly more difficulty in getting the exact look we wanted, we knew we had enough tricks up our sleeves to get over any hurdles. We also liked the idea of establishing a robust and predictable lighting rig which would hold up to full scene animation with a minimum of post work required.

As an added bonus, Sun + Sky setups can also be pretty snappy to render.

Our approach here reflected the freedom of an internal project: we started off with a goal in mind but allowed the finer details to evolve over the course of production (Fig.13 - 14).

_Fig.

_Fig.

_Fig.

_Fig.

Creatively, we wanted to achieve a rich image with strong contrast in both tone and colour. The central characters needed to stand out against the detail in the environment, and overall the piece should have an oppressive feel to hint at the crowded and threatening back-alley surroundings beyond the frame. Light and shadow were to play a big part in the composition.

To explore the lighting we used a combination of concept sketches and paintovers of 'low quality' renders. By flipping between these methods, we could easily identify and flag-up key areas which weren't working and get a clear idea of what needed to change to bring these up. At this stage we were making extensive use of two great tools: LPM and PhotoStudio.

Lukas Lepicovsky's LPM (http://www.lukashi.com/LPM.php) is a render pass manager for Max which allows you to set off multiple render variations without having to remember the complex per-render tweaks every time (Fig.15). This was really useful for crafting our own specific render elements, such as a tweaked direct-light-only pass, and it also let us create and then automatically re-use high-quality/low-resolution Final Gather maps in a completely hands-off way - keeping render times down when we needed to iterate the most.



Fig. 12 _Fig.

Fig. 12 _Fig.

Thorsten Hartmann's PhotoStudio (http://www.infinity-vision.de/PhotoStudio) provides - among other things - a central location for tweaking the multitude of 3ds Max settings to do with exposure, glare, depth-of-field, colour-correction and gamma. It's also great for zeroing all of these, to get a nice clean render from which the process of balancing can start. Its main purpose is to create beautiful and polished renders, but we actually put it to use as part of the paintover process, exploring what needed to be done via quick tweaks in PhotoStudio before going back to the scene and getting the same effect from the scene lighting rather than in post.

We kicked out nightly renders over the course of the project (some examples in Fig.16 - 17) at high enough resolution to ensure we could see the day's changes in a realistic context. Frame sizes varied between 2500px and 4000px high. For those interested, our PCs are Q9450s (single quad cores) with 8GB each, running Vista x64. The scene plus textures eats up about 6GB when loaded - this could have been optimised, but wasn't really necessary for this project.

_Fig.

_Fig.

_Fig.

_Fig.

The Result

So there we are - a whistle-stop tour of what was involved in bringing together Tough Love. We hope you've enjoyed both the article and the final image. Thanks for reading.

Final Image

To see more by Etienne Jabbour, check out Digital Art Masters: Volume 7

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