Cooking Up "Ratatouille" Kitchen

Ben Cooper is a lighting artist, compositor and LightWave 3D generalist. He’s been working in the animation industry for more than eight years, specializing in film and television projects throughout his career. He was recently involved in the creation of the animated short film "Hooked”—his contribution included lighting, shading and 90% of the compositing for the project. Now Cooper shares his experience using LightWave to create a contest entry for one of the popular CGsociety Lighting Challenge #29 that was a “Tribute to Pixar.” The challenge provided the model of the set and the participants in the challenge created their own CG magic to create the final image.

Now he shares how he created the final “Ratatouille Kitchen” image using LightWave for lighting shading, and texturing along with Photoshop and Fusion 6.4.

Before getting started, I studied the provided set for the challenge, choosing an angle that appealed to me. The point of the lighting challenge was to capture the look and feel of the "Ratatouille" film by Pixar.

I love the feeling of warmth that the Pixar artists create in the kitchen, and did my best to replicate it in my scene. It was fun to observe how the surfaces were treated in the film, then recreating the look in my own pipeline. My final render was selected and hosted in the online gallery for the challenge.

I use LightWave 3D for my lighting, shading, texturing and rendering. I love the look of an image that you can create with the LightWave native renderer. I find the surfacing tools in LightWave very user-friendly and the real-time renderer and VPR, can make tedious time-consuming tasks an absolute breeze. LightWave's Area lights are also a joy to work with, you can get accurate, beautiful shadows with a soft edge fall off very quickly without negatively affecting render times. The other great advantage of LightWave is that, to my knowledge, if you own a license for one copy, you can have unlimited render node license use, which is an astronomical saving for any studio.

Lighting

When I start a lighting rig, the first thing I establish are my light sources and how they cast lights into the environment. For this model, I was working with an interior environment that was quite large, and concluded there would be lights outside of the shot that will affect the final look.

After receiving the greyscale model, I needed to do a bit of geometry cleanup on some objects that did not translate too well from Maya to LightWave. LightWave does not like polygons that have more than four edges (not quads), something that most LightWave users are used to. Generally it’s much neater to have quads when sending objects to apps like Zbrush, for example.

My lighting set up had prominent lights inside the oven canopies, with gentle overall illumination achieved by an overhead area light utilizing Monte Carlo Radiosity for light bounce. For animation I would usually use Final Gather, as it calculates faster than Monte Carlo, but Monte Carlo is more accurate, which is why it takes longer.

 

The purpose of the lighting challenge was to replicate the look of the “Ratatouille” film, so I would study my reference images and try to figure out how to achieve the look Pixar achieved. When creating the shading setup for the floor, I knew that it was going to need to be reflective, but I wanted to stay away from that artificial crisp raytrace CG look. Instead, I experimented with getting the right amount of reflectivity with the right lighting and reflection blur settings, finding the sweet spot to make the reflections appear more natural.

Materials - Metals

Here we have a screen grab of the Conductor Material. This shader is great for creating metal surfaces.

[Image007.jpg / Conductor Material]

Once you are familiar with setting up a shader, it's a pretty straightforward process.

The two main settings for a shader are Specularity and Roughness. The more specular you make the shader, the more chrome like it becomes with more defined reflections and pronounced specular highlight. The rougher the shader, the softer the edges of your specular highlight. For a blurrier reflection, enable the blur reflection setting in the shader, and add more roughness value.

Texturing

The texturing was accomplished by simply observing what textures had been established by Pixar in the film and replicating the look and feel. I used Photoshop for creating all the image maps used in the render.

One thing that I did find challenging was that the lights that I placed in my scene did a great job on the overall lighting, but I wasn't happy with how they were affecting some of the shaders.

 

Some metals would still look quite dull because of the angle of the object, which was not getting hit properly by the main lights. This was happening because there was a lack of specular highlight that needed to be addressed.

I then added point lights and set them to only cast specular highlight. Then, using the LightWave VPR, I was able to place my specular lights and get real time feedback.

Rendering

For this shot, I set up a camera with a 1280x720 resolution and utilized the Classic reconstruction filter with a 0.5 oversample sample setting to give the frame a slightly softer appearance that makes it look more film-like. LightWave 11's shading sampling is also connected to the anti-aliasing. To get a nice clean render, I used 12x AA.

Upon rendering, if you have not cached your GI, LightWave will first calculate the radiosity and then start off on the actual render.

I am very fortunate to have a workstation at our studio that has 32GB of RAM and a 16-thread processor--it makes my test renders speedy.

All the lights are set to use raytrace shadows, which make it accurate. The area lights are scaled to for a non-cg shadow look.

The color layer and ambient occlusion layer are in two seperate scenes, for no particular reason other than it was just the way i chose to go about it.
For my ambient occlusion pass, I used the LightWave Occlusion II shader, using a range setting of 2ms for this image.

[Image013.jpg / Ambient occlusion shader settings]

Compositing

Here we have the composite of my image in Fusion 6.4. I organized all my parts of the comp with the underlay tiles.

The Master Color section, is where i add the master color render pass and a color corrector to a small part of a bottle that was getting too bright.
Ambient Occlusion was then added and set to Multiply over the image at a level of 0.5.

The bowl on the right had a very crisp reflection on the worktop, so i decided to blur the reflection in post using a mask with a soft edge added to a blur node.

Next, i added an Overlay layer with a 0.3 level of opacity and blurred it a bit, just to enrich the color a bit more. The color of the copper utensils still didn’t look right to me, so I adjusted it using an alpha mask and a color corrector to tweak it.

I did a fake depth blur effect in post using a mask and blur node—a lot of care went into creating the mask—I kept experimenting to get just the right look.

To achieve a film-type look, I added a combination of glow effects. The first was the Soft Glow node that focuses more around actual highlights to create a glow effect where a surface has a specular highlight, or gets affected brightly by the light rig. The second glow effect was a FuseGlow node added, which created a softer overall glow effect that lightly softened the overall image.

Additional Settings