What is HDR or HDRI maps?
HDR or High Dynamic Range image is one of the latest technology in 3D computer graphics.
It has been widely used to create very realistic 3D renderings.
Many 3D programs support this format of HDR. Lightwave, 3D Studio Max and Maya all support this format.
Basically, it allows a wider range of colour tones to be rendered in 3D computer graphics. This results in images with very high photorealism.