This is a tool for combining render output from multiple render sessions. A typical use case is the same scene being rendered by multiple machines, each producing a different render output. We call these render outputs "films". Multiple films can be merged into a single film in various ways. For example, statistically independent films can be merged into a more converged film with reduced noise and bias.

Note: If you are building the engine from source, you may need to enable the CMake option PH_BUILD_OPTIONAL_TOOLS to build this tool.

Available Options

Primary usage:

[<film-path> [-w <weight>]]... [-o <image-path>] [-of <image-format>] [--help]

See below for more information about the arguments.

Options	Effects
`<film-path>`	File path of the film to merge.
`-w <weight>`	Specify a weighting factor for the film. If the film format does not come with weighting factors, 1 will be used.
`-o <image-path>`	Specify output path for the merged image. This should be a filename without the extension part. Note that the application will not create the directory for you if it is not already exists. (default path: `"./merged_image"`)
`-of <image-format>`	Specify the format of the merged image. Supported formats are: png, jpg, bmp, tga, hdr, exr, pfm. (default format: exr)
`--help`	Print this help message then exit.

Examples

All following commands are expected to be executed from the build/install directory.

To merge three films into a new one named "./merged.exr", use the following command:

./bin/FilmMerger "./film1.exr" "./film2.exr" "./film3.exr" -o "./merged"

You can also specify a weighting factor for each film. In the following example, two films are merged with a 1:2 ratio:

./bin/FilmMerger "./film1.exr" -w 1 "./film2.exr" -w 2

The film merger tool accepts an arbitrary number of films.