Lesson 4 : Render Setup
A lookdev scene, or rendering development, is a crucial step in the creation of 3D images or animations. It focuses on the final visual appearance of a 3D model by applying textures, materials, lights, and other visual properties.
Table of Contents
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1. Important tools for a Lookdev Scene
2. Turntable
3. Camera Setting
4. The famous Grey (0.18)
5. Sources
1. Important tools for a Lookdev Scene
we'll learn what a rendersetup is, how to do it, how to do it for a lookdev scene and much more.Â
The lookdev scene is an exploratory and experimental step aimed at refining the visual appearance of a 3D creation before moving on to the final rendering phase. It provides artists with in-depth creative control. Let's explore together the different tools that make it so distinctive :
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Macbeth:
In lookdev, a Macbeth chart is a tool used to calibrate and assess color and lighting in the creation of digital images. The Macbeth chart, also known as ColorChecker, is a card containing multiple standardized and known color patches. Each patch has a specific color and is designed to be used as a reference during the creation and manipulation of textures, lighting, and materials in graphic creation software used in animation, film, video games, and other industries.
By using a Macbeth chart in the lookdev process, artists can:
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Calibrate Colors: Ensure that the colors of textures and materials in the scene match the real colors represented on the chart.
Evaluate Color Consistency: The colors on the chart serve as a reference to check the consistency of hues and tones in lighting and materials.
Standardize Renders: Having a standard reference helps make colors and textures consistent throughout the creation process.
Color Correction: If necessary, the Macbeth chart can also be used to adjust and correct colors during post-production, ensuring that tones are true to reality.
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In summary, the Macbeth chart is a fundamental tool to ensure color accuracy, visual consistency, and fidelity in renders throughout the visual creation and look development process.
HDRI Studio
A High Dynamic Range Imaging (HDRI) Studio is a virtual environment used in graphic creation to simulate realistic and complex lighting conditions. It is a method that captures and represents more precise lighting information than traditional images can offer. For the lookdev rendering scene, we create an HDRI based on a real, physical studio. This allows us to achieve reflections as if we were in an actual studio.
Poly Haven HDRI / https://polyhaven.com/hdris/studio
A HDRI Studio typically consists of a 360-degree HDR image that captures light data across an extensive dynamic range. This image is often created by taking multiple photos of a real environment at different exposures and then combining them to gather information on both highlights and shadows.
The use of an HDRI Studio offers several advantages:
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Realistic Lighting: HDRI accurately captures the nuances and intensity of light in a real environment, enabling the reproduction of natural and realistic lighting conditions.
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Precise Reflections and Refractions: Due to the high precision of light information, HDRI allows the generation of realistic reflections and refractions on the surfaces of virtual objects.
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Compositing and Integration: HDRI is often used to integrate virtual objects into real environments, facilitating the creation of credible visual effects.
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Lighting Control: Artists can adjust and manipulate the lighting in an HDRI Studio to achieve different visual effects and atmospheres.
Poly Haven HDRI / https://polyhaven.com/hdris/studio
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Poly Haven HDRI / https://polyhaven.com/hdris/studio
The Measurement Tool is a rather important element to bring realism to the rendering; it allows establishing the scale of the rendering and the object size.
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A Grey Chart, in look development, is a tool used to aid in establishing precise references regarding exposure, brightness, and contrast when creating digital images. Also known as a Grey Card or Grayscale Chart, this chart is composed of various shades of gray ranging from black to white, with intermediate values between these extremes.
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​When used in the look development process, the Grey Chart serves several purposes:
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Brightness calibration: The different shades of gray on the chart act as a reference to adjust the scene lighting, ensuring that dark and light areas have the correct brightness values.
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Contrast control: By using the Grey Chart, artists can assess and adjust the image's contrast, ensuring that details in shadow and light areas are accurately rendered.
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Color neutrality reference: The shades of gray are also useful for checking color neutrality, ensuring that gray tones don't have an undesirable color cast.
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Consistency in renderings: By using a Grey Chart as a reference, artists can maintain visual consistency in their renderings, which is essential for ensuring consistent quality in the images.
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In summary, the Grey Chart is a valuable tool in look development as it provides a standardized visual reference to adjust and control brightness, contrast, and color neutrality, thus guaranteeing visually consistent and accurate renderings.
Here is a render setup by RenderFactory. You'll be able to access it in the site's shop.Â
The placement of lights: it's important to position at least two lights on each side of the object to achieve neutral lighting.
The intensities can vary between the two. For instance, in the Bumblebee turn scene, the (a) light is set with : Intensity 1 / Explosure 2 and the (b) light with : Intensity 1 / Explosure 1.2
2. Turntable
Turntable
In 3D look development, a "turntable" refers to an animation where a 3D model or scene is rotated at a fixed viewing angle, often on a central axis, to showcase the model from different perspectives. It is a common way to display a 3D object or character from all angles, allowing artists, art directors, or clients to better assess the model's appearance, textures, materials, and modeling from various viewpoints. These animations are often used for presentations, demonstrations, or evaluations of 3D projects.
Bumblebee Turntable :
Set up by Cave Academy
How to animate lights to create a Turntable?
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To create a turntable by animating lights in a 3D scene, you can follow these general steps:
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Place your model in the scene: Import or create the model you want to showcase in a turntable in your 3D software.
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Place the lights: Add light sources to the scene to illuminate your model. Ensure that lights are positioned to properly illuminate your subject from different angles.
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Create animation for lights: Use the animation features of your software to animate light parameters. You can animate properties such as position, intensity, color, or other light attributes to create interesting visual variations during rotation (360 degrees).
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Set up the camera and animation: Position the camera at a fixed location and oriented towards your model. Create an animation of the camera rotating around the model to achieve the turntable movement.
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Render the animation: Preview the animation to ensure that the rotation movement and lighting variations work as intended. Then, start the rendering process to generate the final animation.
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Here we can see the animation parameters; the lights rotate 360 degrees. It is important to animate the group, and to facilitate a smooth rotation, you can place a locator at the center of your object.
Once you have animated the lights and camera, recorded the animation, and completed the rendering process, you will have a turntable showing your model from different angles with lighting variations.
Here it's a good example for the lambert part (look the variation of the lights during the turntable) :
3. Camera Setting
Camera settings: it's important to adjust the camera parameters and the render scene in LookDev (resolution, sampling, etc.). I invite you to watch the lesson on sampling here: [link].
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For the camera, you can add depth blur to your renders to give a more realistic touch. It will always look better in Maya than in Nuke with the Z-map.
It's important to activate Display/Object Details to see the position of the object you want to set as the focus point (the sharp object). This way, we can input this value into the FOCUS DISTANCE.
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Focus Distance: This determines the distance at which the object is sharp. Setting the focus distance means the object at that distance will appear sharp in the render, while objects in front of or behind it will appear blurry based on their distance from this value.
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F-Stop: The F-Stop controls the camera's aperture. A lower value (like f/2.8) means a wider aperture, creating a more pronounced background blur, whereas a higher value (like f/16) means a smaller aperture with less background blur.
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Focus Region Scale: This scale adjusts the sharpness area around the focus point. A higher value increases the sharp region, while a lower value makes the focus area more precise and narrow.
Renderman Setting for the Depth of field
Focus Distance = 17,328
4. The famous Grey (0.18)
In the realm of look development and image creation, the gray 0.18 refers to a specific gray value used as a standard reference for the exposure and diffuse reflection of surfaces. (Often used for rendering backgrounds.)
This gray level is frequently employed as an average reference for diffuse reflection because it corresponds to the average luminance of many matte or diffusing surfaces under typical lighting conditions. Technically, this value corresponds to approximately 18% of the maximum possible luminance, hence the term '0.18'.
Unit used: cd/m²
The candela / square meter (symbol cd m−2 or cd/m²) is the derived unit of luminance in the International System of Units (SI) corresponding to a luminous intensity of one candela over an area of one square meter.
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The gray 0.18 is used to adjust white balance. For example, on a reference exposure, if we take the black grey as 90 cd/m² and a white grey as 14000 cd/m², what would be the in-between value? One might think it's 745 cd/m², but that's incorrect; the answer is 360 cd/m².
This is due to our flawed perception of color and brightness with our eyes. They don't correspond linearly, which is why in Photography we talk about powers of 2. This means that to find the midpoint between white and black, we don't take the arithmetic average; we take a geometric average. We multiply the numbers and then take the square root:
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90 x 1400 = 126 √126 is 354.9
Here we get the rounded value of 360 cd/m².
The average gray was determined back in 1903, and the 0.18 comes from a halftone process dating back to 1880. Printers used these gray cards to calibrate ink flow. The 0.18 signifies that they reflected 18 percent of the light that struck them. 18% gray comes from the world of print and is based on reflection. An 18% gray card reflects 18% of the light that hits it. It's actually the geometric mean between white paper (reflecting at 95%) and black ink (reflecting at 3.5%).
Eastman Kodak Company, better known as Kodak, is an American company that played a crucial role in the development of photography since the 19th century.
Kodak has developed a very famous gray card that is accurately calibrated. A gray card is a flat object of a neutral gray color derived from a flat reflectance spectrum. A typical example is the Kodak R-27 set, which includes an 8x10" card and a 4x5" card that have a reflectance of 18% in the visible spectrum, and a white reverse side that has a reflectance of 90%.
When Ansel Adams and Fred Archer introduced the Zone System in 1941, they used this 18 percent gray card. In the 20th century, color spaces like LAB were optimized, describing color in terms of (L) for luminance and (a) and (b) for opposing colors (red/green, yellow/blue). The average gray corresponds to 50 percent of (L), which equates to 18.42.
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Ansel Adams, was an iconic American photographer and environmentalist known for his stunning black-and-white landscape photographs, particularly of the American West. His passion for nature developed early in life, influenced by his family's trips to Yosemite National Park.Â
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In the 1920s, Adams became involved with photography and, by the 1930s, had established himself as a prominent photographer. He co-founded Group f/64, a collective of photographers advocating for pure photography and sharp focus. Adams's technical mastery of photography, particularly his zone system—a technique for controlling exposure and development—contributed significantly to his distinct style and impeccable prints.
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Yosemite Valley became a focal point of Adams's work, capturing its majestic beauty and becoming a symbol for conservation efforts. His iconic images, such as "Monolith, the Face of Half Dome" and "Moonrise, Hernandez, New Mexico," reflected his dedication to capturing the essence of the natural world.
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Beyond his photographic achievements, Adams was an advocate for environmental conservation. He used his imagery and influence to promote the preservation of wilderness areas, co-founding the Sierra Club, and contributing to various environmental causes.
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Ansel Adams's legacy extends far beyond his photography. He published numerous books, including the influential "The Camera," and his work continues to inspire photographers and environmentalists globally. He passed away on April 22, 1984, leaving behind a rich legacy of breathtaking imagery and an enduring commitment to the preservation of natural landscapes.
I hope this lesson has served you well !