HDRI 360 Sunrise #38 Sky Panorama for 3D object based lighting

Achieving extreme realism in your 3D scenes requires realistic lighting, shadows, reflections and refractions. Using HDRI images instead of jpeg background images and lights has the advantage of a faster and simpler workflow while delivering spectacularly realistic renders. Achieving professional renders is as easy as dropping an HDRI image onto a sky object and hitting render.

A sky panorama using 32 bit HDR format brings out lifelike reflections and refraction in the glass, while the 8 bit jpeg images looks flat and dull by comparison

In photography, High Dynamic Range Images are typically created by compositing multiple exposures to capture and bring out information in the extreme shadows and highlights of a photograph. These exposures are then tonally mapped using software and merged to create an visually pleasing image.

In 3D, however, the purpose is to make use of the extra the luminance information stored in 32 bit images to bring the same environment that was shot in camera into the 3D environment. While standard jpeg files contain 256 levels of brightness, the information contained in an HDRI image extends into millions of shades of color and luminance.

Thes extra luminance information in HDRI images is sent to the render engine where it is used to create highly realistic reflections, shadows, refractions and specular details on the objects inside the scene when global illumination is turned on in the renderer.

Even without global illumination, HDRI images still bring realistic reflections and refractions that cannot be achieved using an 8 bit jpeg.