The RPF format is the 3ds Max Rich Pixel file format, which supports the ability to include arbitrary image channels.

RPF files replace RLA files as the format of choice for rendering animations requiring further post-production or effects work. Many channels available in RPF files are exclusive to this format. The following topics pertain to the storage type and format used for the RPF format.

• GBuffer - The G-Buffer stores multiple layers at each pixel.
• List of Image (G-Buffer) Channels - This section provides an overview of the image channels available with the GBuffer which relate directly to the multiple layer pixel information stored in the RPF files.
• List of G-Buffer Channels Indices - This section provides a quick overview of the various data size and channel names relating to the G-Buffer and layered pixel storage in RPF files.
• List of G-Buffer Channel Types - This section provides the list of channel types and the size associated with these channels per pixel.
• GBufData - This structure is used by the GBufReader and GBufWriter.
• RealPixel - This structure represents an RGBE based pixel where E is the base 2 exponent of the maximum RGB component while RGB are the mantissas of RG and B relative to E. This will compress the essential data of a floating point based color into 32 bits.

The actual RPF file source code can be found in the SDK samples directory under \samples\images\rla\rla.cpp. The files still refer to RLA instead of RPF for legacy purposes.

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