Creating Photorealistic Environments with HDRIs

In this chapter, we will learn to create photorealistic environments using custom environment textures known as High Dynamic Range Images (HDRIs). We will first discuss what HDRIs are and how they work, before diving into how to acquire them and apply them in Blender.

By the end of this chapter, you will be able to download and apply a custom background to create more realistic scenes in Blender. This will allow you to complete your scene with lighting and backgrounds effortlessly.

The following topics will be covered in this chapter:

• What are HDRIs?
• Downloading HDRIs
• Applying HDRIs in Blender

What are HDRIs?

HDRIs are special images that contain a higher range of brightness values than regular images. This allows them to capture the lighting of a real-life environment, which makes them ideal to simulate environments in a 3D scene in Blender. An HDRI will create a background in our world and project light into our scene, which allows us to complete our projects with better lighting and backgrounds.

Figure 12.1 shows a simple scene that has an HDRI applied as an environment texture.

Figure 12.1 – A simple scene with an HDRI environment

As you can see, the metal sphere looks photorealistic simply because of the lighting and shading cast onto the object from the environment.

Figure 12.2. shows what an HDRI looks like when viewed as a regular image. HDRIs are 360-degree images that can be imported into Blender as a spherical light source.

Figure 12.2 – An HDRI image

To understand how HDRIs work,...

Downloading HDRIs

We will now explore some online libraries for HDRI images. This will allow us to download HDRIs with a wide variety of environments.

The following platforms offer free HDRI images:

• https://polyhaven.com/hdris
• https://hdrmaps.com/freebies/free-hdri-maps/
• https://www.openfootage.net/

Figure 12.5 shows the HDRI section at polyhaven.com. Here, we can get a preview of the 2D image as well as a demonstration of how some common materials would look in these environments.

Figure 12.5 – HDRIs available on polyhaven.com

To download an HDRI from Poly Haven, simply click on an image, and then click on the Download button in the top-right corner.

Figure 12.6 – Downloading an HDRI

The other HDRI libraries work the same, and images can be downloaded by simply clicking on them and using the download button.

We will now have the HDRI saved to our computer in either the .EXR or .hdr...

Applying HDRIs in Blender

We will now learn to apply the downloaded HDRI image in Blender. This technique will allow us to load custom textures as world backgrounds. In the following steps, we will load the .EXR file in Blender using nodes:

1. In the Shading workspace, switch the Shader Editor mode to World, as shown in Figure 12.7.

   This will load a separate node space where we can create materials for the world instead of an object.

Figure 12.7 – Switching to world shading

Here, we will find the Background node, which defines the color and brightness of the environment. This is where we will apply our HDRI background. By default, the environment is dark gray and emits some light, as we can see in Figure 12.8.

Figure 12.8 – Background color as defined by the Background node

We can change this color the same way we change the base color of a material in a Principled BSDF node, as we learned in the Creating...

Summary

In this chapter, we learned how to download HDRIs, import them into Blender, and modify them with some nodes. We can now use HDRIs to create custom backgrounds and realistic environmental lighting. This can help us create beautiful renders with our 3D models and scenes in Blender.

In the next chapter, we will learn to use, set up, and tweak the camera and its settings to create a good foundation to render high-quality images.