Post Processing allows you to additionally trim the grid, exclude certain channels, bake Render Warps or to retime caches.
For Retiming to be successful you need to export Velocity Channel during Default Sim. If you have fire in the scene, you will also need to export the Temperature channel, so that Retimer can properly burn fuel.
Range - Allows user to use different simulation range for Post Processing. If used, the simulation range is defined with Cache Start and Cache End parameters.
Cache Start - First cache frame for post processing.
Cache End - Last cache frame to be processed.
Minimize Grid - You can use this option to let FumeFX minimize grid dimensions, thus reducing cache file size and increase rendering speed. Grid will be shrunk to the smallest possible dimensions, eliminating empty voxels that does not contain significant information.
Bake Render Warps - This option allows to you "bake" Render Warps into the cache files. Once baked, you can disable them inside the Maya Relationship Editor.
Exclude Channels - It is possible to exclude channels that you do not need anymore. For example, you might exclude Temperature channel that you had stored into caches because of Retiming, but you do not need them in the final pass.
Retime - allows you to alter the speed of cache files.
FumeFX allows you to retime simulation based on the velocity in the grid. For Retimer to work properly, the Velocity channel is required in the output caches. In the case of fire simulation, the Temperature channel is required as well. The ability of Retimer to smoothly create new frames greatly depends on the Simulation itself. In the case where a simulation is performing many simulation sub - steps, retiming could be problematic.
Method - You have two methods available to retime your caches.
Time Scale Factor - Use this option to increase or decrease the speed of final animation in an easily perceivable way. As an example, value of 0.5 would create a final animation that is half as fast as the original. By contrast, a value of 2.0 would create a final animation that is twice as fast as the original.
Frame - Using this method, you can create parameter keys at certain Maya frames, specifying which cache frame to load. This can be used if you have to match FumeFX timing to an adjusted object's animation.
Adjust Playback Range Method - If you select this option FumeFX will automatically adjust Play From and Play To parameters inside the Playback rollout, depending on the total number of frames created by the Retiming process.
Note: When retiming the FumeFX grid that contains a particle system, please make sure that particles are cached as otherwise retiming can produce unexpected results.