Cell shading , or toon shading , is a 3D rendering technique that gives images a cartoonish look. It is characterized by strong black outlines and limited color palettes, similar to traditional comics or cartoons. Cell shading is used in many video games, such as Jet Set Radio, XIII, and Borderlands, to create a unique and stylized atmosphere.
The principle of cell shading
Cell shading relies on two main effects: contour drawing and shadow thresholding.
The outline drawing
Contouring involves drawing a black line around 3D objects to make them stand out. There are several methods to achieve this effect, such as multipass, envelope, or depth filtering.
- Multipass rendering involves rendering the object twice: once with its normal color and once with a solid color (black or white). Then, the two images are superimposed, slightly offsetting the second one to create the outline.
- The envelope technique involves creating a copy of the object slightly larger than the original and coloring it black or white. Then, the original object is displayed over the envelope to create the outline.
- The depth filter uses the scene's depth map (which indicates the distance between the camera and each pixel) to detect abrupt changes in depth. These changes correspond to the edges of objects, which can then be colored black or white.
The thresholding of shadows
Shadow thresholding involves replacing light gradients with distinct shades of gray, as seen in comics. There are several methods to achieve this effect, such as using a 1D texture or a pixel shader.
- Using a 1D texture involves creating a texture that contains the different shades of gray you want to use. Then, you apply this texture to the object based on its lighting. For example, if the object is illuminated at 50%, you would apply the color located in the middle of the 1D texture.
- Using a pixel shader involves programming a function that calculates the color of each pixel based on its lighting. For example, if the object is 50% lit, it is assigned a color that corresponds to a predefined threshold.
The advantages of cell shading
Cell shading offers several advantages over realistic rendering:
- It allows for the creation of an original and recognizable graphic style, which stands out from other games.
- It allows for more expressiveness and personality in the characters, by exaggerating their facial expressions or emotions.
- It saves graphic resources by using fewer textures or details.
- It helps to mask certain visual defects, such as aliasing or clipping.
But to truly benefit from cell shading, you also need a good graphics card. Among the most reputable brands is AMD Radeon, which offers high-performance and affordable cards. The best AMD Radeon graphics cards can handle cell shading brilliantly, offering high resolution, fast refresh rates, and low power consumption.
The disadvantages of cell shading
Cell shading also has some drawbacks compared to realistic rendering:
- It may be perceived as too childish or too simplistic by some players, who prefer a more immersive or more realistic rendering.
- It can be difficult to adapt to certain game genres, such as horror games or historical games, which require a darker or more believable atmosphere.
- It can be difficult to master, as it requires a good artistic sense and a good knowledge of 3D rendering techniques.
FAQ
Which games use cell shading?
There are many games that use cell shading, such as Jet Set Radio, XIII, Borderlands, The Legend of Zelda: The Wind Waker, Okami, Dragon Ball Z: Budokai, Viewtiful Joe, etc.
How to do cell shading with Photoshop?
There are several tutorials that explain how to do cell shading with Photoshop, such as this one: https://www.youtube.com/watch?v=4wz7n2f0l9g
What is the difference between cell shading and flat shading?
Flat shading is a 3D rendering technique that gives each face of an object a uniform color, regardless of lighting. Cell shading is a 3D rendering technique that gives each pixel of an object a color based on its lighting, but using distinct shades of gray. Flat shading gives objects a more geometric and simplistic appearance, while cell shading gives them a more cartoonish and stylized look.
What is the difference between cell shading and comic shading?
Comic shading is a 3D rendering technique that adds extra effects to images to make them resemble comics, such as speech bubbles, onomamouseeia, panels, and so on. Cell shading is a 3D rendering technique that modifies the color and outlines of objects to make them resemble cartoons. Comic shading can use cell shading as a base, but it can also use other rendering techniques.
What is the origin of the term cell shading?
The term cell shading comes from the English word cel-shading, which refers to celluloids, the transparent sheets on which the characters and backgrounds of traditional cartoons were drawn. These sheets were then layered onto a background to create the final image. The term cel-shading was coined by Sega to describe the technique used in the game Jet Set Radio.
Conclusion
Cell shading is a 3D rendering technique that creates cartoon-like images. It relies on contour drawing and shadow thresholding, giving objects a cartoonish appearance. Cell shading is used in many video games to create a unique and stylized atmosphere. To optimize the graphics performance of these games, it is recommended to install Vulkan Runtime , a software library that allows you to fully utilize the capabilities of your graphics card. Vulkan Runtime is compatible with most operating systems and gaming platforms. It has advantages and disadvantages compared to realistic rendering, and it requires a good artistic sense and a solid understanding of 3D rendering techniques.
