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The minmax information that is generated by vdbmake is used in conjunction with volumes that have Attribute "volume" "int dsominmax" [1] to greatly decrease time to first pixel for aggregate volumes. The additional information takes the form of a dual mipmap pyramid that contains the minimum and maximum values of the source grid. By default, any float grids in the input file that are processed for mipmapping will also have generate minmax information. As a space optimization, the optional -minmax parameter can be used to specify the name of the source grid that contains the density information; grids that do not match this name may get mipmapped but will not generate the additional dual minmax pyramid data.

> vdbmake -minmax density input.vdb output.vdb

Note that if the minmax data is not present in the VDB file, impl_openvdb will still generate it on the fly at load time if Attribute "volume" "int dsominmax" [1] is set. This may slow down time to first pixel somewhat.

Including vdbmake in your own toolchain

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