Display a high dynamic range image

You can load a floating-point image into Maya as a file texture and control its exposure for preview. Supported formats include OpenEXR, TIFF, and DDS. High dynamic range images can now be displayed in the scene view, in the material swatch, or in the rendered image. For display preview purposes, floating point images are reduced to fixed point precision.

During final rendering (including hardware shaders), the original image is used with its full dynamic range.

To use this feature, you must use a plug-in that loads high dynamic range images into Maya and convert them to fixed-point. The following sample API plug-ins have been provided with Maya:

• OpenEXR.mll - reads .exr images. OpenEXR is a high dynamic range (HDR) file format developed by Industrial Light and Magic ^®
• ddsFloatReader.mll - reads either half (16-bit) or IEEE 32-bit floating point .dds images
• tiffFloatReader.mll - reads IEEE-32bit floating point .tif images

For all of .tif, .dds, and .exr, only individual 2D images are supported. That is, concatenated or multiple embedded images, (including cube maps, and 3d textures) are not supported. This is equivalent to the support specification for existing IMF based plug-ins. In addition, compression is not supported in the plug-ins as all of .tif, .dds, and .exr do not support floating point compression at this time.

To display an OpenEXR image and control its exposure:

1. Load the plug-in for the desired format using the Plug-in Manager (Window > Settings/Preferences > Plug-in Manager), for example, OpenEXR.mll.
2. In the file texture node, expand the High Dynamic Range Image Preview Options section. Select the desired conversion via the Float to Fixed Point attribute. There are three types of conversion available:
   • Clamp

   All color values in your image that are outside the range of 0 and 1 are clamped. Values higher than 1 are clamped to 1 and values lower than 0 are clamped to 0.

   • Linear

   Normalize the color values in your image to be between 0 and 1.

   • Exponential

   Retain the lowest and highest color values and ensure that the remaining color values have a reasonable contrast.

3. Adjust the exposure level via the slider bar as desired (only applicable if Exponential is selected as the conversion method).