What is a HDRI map?

A HDRI map is a high-dynamic range image that contains all the information necessary to light a 3D scene. A HDRI map can be used in conjunction with 3D software to create realistic lighting effects.

What is HDRI used for?

High dynamic range imaging (HDRI or HDR) is a technique used in imaging and photography to allow for a greater dynamic range between the lightest and darkest areas of an image than standard digital imaging techniques or photographic methods. This wider dynamic range allows HDRI images to more accurately represent the wide range of intensity levels found in real scenes, from direct sunlight to shadows.

HDRI can be used for a number of different applications, including:

1. Capturing high-contrast scenes: Traditional photography can often struggle to accurately represent both the very dark and very bright parts of a scene. This can result in washed out highlights or blocked up shadows. By using an HDRI map, you can more accurately capture the full contrast of a scene.

2. Enhancing details in shadows and highlights: By correctly exposing an HDRI image, you can bring out more detail in both the shadows and highlights than you would be able to with a traditional image. This can be particularly useful when post-processing images, as it gives you more information to work with.

3. Creating realistic lighting effects: One of the most popular uses for HDRI maps is in creating realistic lighting effects in 3D rendering applications. By using an HDRI map of a real world location, you can create incredibly realistic lighting conditions that would be difficult or impossible to recreate with traditional methods.

Test Rendering created with KeyShot

HDR File Formats

HDR image files come in a variety of formats, each with its own strengths and weaknesses. The most common HDR file formats are .hdr and .exr.

.hdr files are the most widely used HDR file format. They are supported by a wide range of software, including Adobe Photoshop and Autodesk Maya. .hdr files are also relatively easy to create, making them a good choice for beginners. However, they have some drawbacks. .hdr files can be large, making them difficult to work with on slower computers. They can also be tricky to edit, since they often contain a lot of data that can be hard to change without destroying the image entirely.

.exr files are less common than .hdr files, but they are slowly becoming more popular. They are supported by some professional-grade software, such as Nuke and After Effects. .exr files have several advantages over .hdr files. They can be much smaller than .hdr files, making them easier to work with on slower computers. They can also be edited more easily, since they contain less data overall. However, .exr files can be more difficult to create than .hdr files, so they may not be suitable for beginners.

Published Date: 2022-10-21