Autodesk 12812-051462-9011 User Guide 3 - Page 2103

an alpha channel but don't require the alpha data, choose the RGB version to save some memory. If you choose a storage type that supports alpha, but load an image without alpha, no memory is allocated for the alpha channel; the loader detects the situation and reverts to the alpha channel-free storage option with equivalent RGB bit depth. The options supports the HDR bitmap storage options. This allows storage of the high-dynamic-range data within 3ds Max in three different HDR formats: 24- and 32-bit LogLUV formats and 32-bit RealPixel format. EXR files loaded using these storage modes are suitable for use as environment maps for reflections and skylight. Color Transform Because EXR images often contain values brighter than "white," it is often desirable to change the luminance range in the source image over which black to white occurs; that is, to remap the color data. When Color Transform is on, you can adjust these luminance and general brightness controls: Exponent The exponent to apply when loading the file Black Point Where black should be in the luminance range of the image White Point The white point RGB Level A standard multiplier for the RGB data RGB Offset An additive offset for the RGB data Preview The Preview window provides for interactive previewing of color-transform options for loading EXR files. After choosing an EXR file to open, click Preview to enable the preview window. The image file is loaded into the preview window, and from then on any changes to the Color Transform options update the thumbnail in real time. The preview window ignores the aspect ratio of the image to make the most of the small screen space available. Plugin About Opens a dialog that shows information about the OpenEXR plug-in. File Info Opens the File Information dialog on page 7359, which lets you view file statistics plus any attributes and channels stored in the file. OK Accepts any changes, closes the dialog, and opens the image file. Cancel Discards any changes and closes the dialog without loading the image file. 7358 | Chapter 23 Managing Scenes and Projects