Introduction to HDRI Lighting

HDRI stands for High Dynamic Range Imaging. It's a technique that uses lighting information from real-world scenes to illuminate 3D environments, providing natural and realistic lighting effects with varied luminance.

HDRIs are captured using a camera with bracketed exposures, often of panoramic scenes. The multiple exposures are combined to record a greater range of luminance than standard digital imaging.

Most 3D software can import HDRI maps to create a lighting environment. This envelops the scene, offering reflections, lighting, and shadow details that respond naturally to camera movement.

Materials in a 3D scene can reflect the HDRI environment. This is particularly essential for reflective and glossy surfaces, as they exhibit realistic reflections and complex light interactions.

The dynamic range of an HDRI ensures that bright spots (like the sun) emit significantly more light than other areas, which is crucial for maintaining realistic lighting ratios and intensities in 3D scenes.

You can adjust HDRI maps in image editing software to alter the lighting mood, intensity, or to add specific light sources before applying them to your 3D scene.

Advanced methods include using HDRI for Image-Based Lighting (IBL), where the environment map contributes not just to direct lighting but also to indirect bounced light within the scene.