Essential Techniques for Effective 3D Scene Lighting: Key, Fill, and Rim Lights

Guillaume Chichmanov
May 17, 2024

When it comes to lighting a scene, there are several aspects we need to consider to highlight all the details in the best possible way effectively. This article is written by Matias, 3D generalist at Cominted Labs, he will outline the main steps to achieve professional scene lighting!

The first step is to identify the type of scene we want to illuminate, whether it's a character, an object, or even a landscape. Depending on what needs to be illuminated, the steps will vary. In this article, we will go over the steps to illuminate a character that we designed for a horror video game called Pneumata. This methodology can also be applied to any type of 3D model.


If you want to illuminate an entire scene without highlighting a specific model, the most common approach is to use HDRIs (High Dynamic Range Images). These are equirectangular (spherical) images that envelop the entire scene. As their name suggests, HDRIs serve to emulate the entire environment, including light sources, which are stored within them.

When using real-world images, the results can be highly realistic. When choosing the appropriate HDRI, it's essential to consider the location where the scene takes place, the time of day, and even the weather conditions.

If we want to apply an HDRI in Blender, we need to go to the "World" settings, click on the yellow circle next to "Color," and select "Environment Texture".

Afterward, we select the downloaded HDRI, and we're good to go. To find the best HDRIs, we recommend the website:

Key Light

The key light is the primary light source in a lighting setup. It's typically placed at an angle relative to the subject to create depth and dimensionality. This light establishes the overall lighting direction and intensity, emphasizing the form of the character or subject. It also helps to create shadows, adding depth and realism to the scene. The key light is crucial for setting the mood and highlighting the most important aspects of the character or subject.


Example only with the Key Light.

Fill Light

The fill light is a secondary light source used to fill in the shadows created by the key light. It's positioned opposite the key light to soften shadows and reduce their intensity. The fill light helps to balance the overall lighting in the scene, providing additional illumination to areas that may appear too dark due to the key light's direction. It contributes to creating a more even and natural-looking lighting setup, enhancing the character or subject's appearance without overpowering the key light's effect.


Example with the Key Light + Fill Light.

Rim Light / BackLight

The rim light, also known as edge or backlight, is positioned behind the subject and off to the side. Its purpose is to create a thin, bright outline around the edges of the character or object, separating it from the background and adding depth to the scene. The rim light helps to accentuate the silhouette of the subject, making it stand out against the background and giving it a three-dimensional appearance. This light is particularly effective in highlighting the contours and details of the character or object, enhancing its visual presence within the scene.

Example with all the Lights, Key Light + Fill Light + Rim Light.

Here is an image where you can see where these 3 types of lights should be positioned to achieve an optimal result.

Soft and Hard shadows

In essence, hard shadows have distinct edges, while soft shadows have smoother, more diffused edges. These differences can significantly impact the mood and realism of a 3D scene.

To switch between soft and hard shadows, it is necessary to change the "Radius" parameter in the light settings that we want to modify, the higher the Radius number, the softer the shadow will be, on the contrary, the smaller the Radius number, the harder the shadow will be.

- Hard Shadows: These shadows have well-defined, sharp edges. They occur when the light source is small or distant, resulting in a focused shadow with clear boundaries.

- Soft Shadows: Soft shadows have more gradual transitions between light and dark areas, creating a smoother, softer edge. They occur when the light source is large or closer to the object, causing light to scatter more, resulting in a softer shadow edge.

To conclude...

In summary, achieving professional scene lighting in 3D requires a strategic approach. By utilizing HDRIs and mastering key, fill, and rim lights, artists can enhance the visual impact of their work. Overall, implementing these techniques elevates the quality of 3D renders, ensuring all details are effectively highlighted.

If you are building a game and looking for an efficient and cost effective outsourcing partner, Cominted Labs is at your service. We are a leading game art outsourcing platform that has collaborated with over 50 leading game publishers and developers. Our clients include TCG World, Perp Games, Ethereum Towers, Baby Doge, Crossmint, MadWorld, and many more.

Contact us today and book a demo with an intro call.

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