VRay for 3ds Max Manual

.vrimg to .exr Converter

Search Keywords: vrimg, OpenEXR, converter, high-dynamic range, HDR, HDRI

General

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This is a command-line utility that can be used to convert .vrimg image files to .exr files in OpenEXR format. The .vrimg file format is a special format used by the V-Ray VFB to store the rendered image incrementally while rendering, in full floating-point format, will all available render elements.

Installation

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By default, the installation of V-Ray for 3ds Max installs the .vrimg to .exr converter in the folder [Program Files]\Chaos Group\V-Ray\3dsmax Rx for yyy\tools. A shortcut to the converter is also installed in the Start Menu: click Start Menu > Programs > Chaos Group > V-Ray for 3dsmax > Tools > VRImg to OpenEXR converter.

Usage

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There are two methods for running the vrimg2exr converter:

• Converting a single .vrimg file to a single .exr file:

  > vrimg2exr <vrimg_file> <exr_file> [options]

  In this case, the <vrimg_file> cannot contain wildcards. Note that the .exr extension is not added automatically to the output file name.

• Converting multiple .vrimg files to multiple .exr files:

  > vrimg2exr <vrimg_wildcard> [options]

  In this case, <vrimg_wildcard> can contain the wild-card symbols '*' and '?'; the .vrimg files will automatically be converted to OpenEXR files with the .exr file extension.

In both cases, the original .vrimg file is not deleted.

Options

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One or more of the following options may be specified:

Option	Description
-info	Prints information about the .vrimg file (resolution, channels present etc). This is only supported for .vrimg files created with V-Ray versions 1.48.xx and higher.
-half	Stores the floating-point data in the .exr file as 16-bit floating point numbers. If this option is not specified, the data is stored as 32-bit floating point numbers.
-sRGB	Converts the RGB data from the .vrimg file to the sRGB color space before writing it to the .exr file. Without this option, no color conversion is performed.
-channel <name>	Only reads the specified channel from the .vrimg file and writes it as the RGB channel in the output file. No other channels are written to the .exr file. This option can be used to extract the different channels in the .vrimg file to separate image files. Currently supported values for <name> are: Atmosphere, Background, Diffuse, Reflect, Refract, SelfIllum, Shadow, Specular, Light, GI, Caustics, RawGI, RawLight, RealColor, MtlID, RenderID, ObjectID, RGB Color, Alpha
-compression <method>	Sets the compression type for the resulting .exr file. If not specified, ZIP compression is used. Currently supported values for <method> are: none, zips, zip, piz, pxr24
-bufsize <buf size>	The maximum buffer size per channel (in megabytes) that will be used for the conversion. If the image does not fit into that buffer size, the converter will process it in several passes. Larger buffer size means faster conversion, but, obviously, requires more memory. The default is 10 MB per channel.