The tyCache modifier is an alternative to 3ds Max’s built-in Point Cache modifier, that has no restrictions on the type of mesh input it can cache. Caches can preserve changing topology, animated UVWs, animated explicit normals, etc.
tyCaches exported from an Export Particles operator within a flow cannot be loaded by a tyCache modifier, and vice versa. The two file formats share the same base name (“tyCache”) but are not interchangeable. Caches saved with a tyCache modifier can only be loaded by a tyCache modifier - and caches exported from an Export Particles operator can only be loaded by a tyCache object.
tyCache modifiers can be instanced across multiple objects. If cache mode is set to “Save in .max file”, the modifier will automatically save each object’s cache to the appropriate data chunk in the .max file. If cache mode is set to “Save in external file”, the modifier will assign a unique 6-character hash value to each object (stored in its user properties buffer under the “tyCacheModID” key), and then append that hash value to the specified output filename for each cache (internally). So, for example, if you instance the tyCache modifier across 3 objects and set the output path to “C:\cache.tycm”, the actual output cache names might look something like “C:\cache[P1TV39].tycm”, “C:\cache[TD2R0l].tycm” and “C:\cache_[A8MMDR].tycm”. This system prevents objects from overwriting each other’s caches when exporting from an instanced modifier.
Filename: the cache file to load, from disk, when mode set to “save in external file”
Keep cache in RAM: when disabled, no cache data will persist in memory between evaluations of the modifier.
While disabling “keep cache in RAM” can improve RAM usage in scenes with heavy caches, it can lead to significantly longer evaluation times, because the entire cache must be re-read from disk each time the modifier is evaluated. Disable this setting with caution!
Start/end frame: controls the time range that will be cached.
Time step: controls the size of a time step (in frame units) between each cached frame. Values lower than 1 will create larger caches due to sub-frame data being cached.
Once a cache is saved, you can disable all modifiers below the tyCache modifier (even modifiers that change mesh topology) - the cache contains all data required to perfectly recreate the mesh at any given cache frame.
Users can use MAXScript to export caches from a tyCache modifier by calling the “cache()” function on the modifier. If any errors occur during export, they will be printed to the MAXScript listener.
Frame offset: offsets the timing of sequence playback.
Clamp frame range: controls whether the input sequence frame range will be clamped.
Clamp range: define the clamped frame range of the sequence.
Hold: requested frames outside of the clamp range will be set to the nearest frame within the clamp range.
Blank: requested frames outside of the clamp range will be empty/ignored.
Loop: requested frames outside of the clamp range will be set to loop within the clamp range.
In hold mode, a requested frame of 125 in a clamp range of 0-100 will be set to 100. In loop mode, a requested frame of 125 in a clamp range of 0-100 will be set to 25.
When “round to nearest frame” is enabled, deformation motion blur will no longer occur.
Enable retimer: controls whether playback will be controlled by the retimer frame value.
Retime type: controls whether the retimer affects playback frame or speed.
Speed %: the percent value that controls playback speed.
Ref Frame: the reference frame that the speed multiplier will be relative to.
Setting a proper reference frame is important for the speed multiplier. The reference frame should typically be the start frame of your playback sequence, not necessarily the start frame of the tyCache.The equation for the speed retimer is:playbackFrame = [referenceFrame + abs(time - referenceFrame) * speed * sign(time - referenceFrame)].