Prepare your Bifröst simulation for user caching
To reduce unnecessary computations and memory requirements while you generate a user cache, do the following:
- If you have multiple Bifröst simulations in the scene, you can temporarily turn off the simulations you are not user caching. To do this, uncheck
Enable in the
Container Attributes group of the main container nodes.
- It is best to disable the scratch cache to avoid excessive memory use and disk access. If both the user cache and scratch cache are enabled at the same time, the user cache gets written or read from disk, and in addition the scratch cache keeps those frames in memory until the memory limit is exceeded, at which point the scratch cache also gets offloaded to temporary files. To disable the scratch cache if it is in use:
Create a user cache for all the cacheable objects in the scene
This method simultaneously creates individual user caches for all the cacheable objects in the scene, including caches for liquid, aero, foam, and collider objects. Use this method if you plan to extend the frame range of your simulation by appending newly cached frames to the existing user cache. See
Append to an existing Bifröst user cache.
- Select the container for the simulation that you want to cache.
- Make sure that the settings are as desired. For example:
Compression format is set to the appropriate quality.
Cache Elements are enabled.
Cache time range is set to begin at the
Start Frame of the simulation set in the
Simulation Attributes group of the main container node.
- Write Mode is set to
Compute and Cache Options.
Enable Background Processing is off, the requested frames are sent to the Bifröst Computation Server one at a time and you must wait for them all to be processed before you can interact in Maya.
The user cache gets written to disk. In addition, the following things happen:
- Frames that have been computed and cached are displayed in blue on the
Time Slider. However, if you did not disable the scratch cache, then any frames that are also in the scratch cache are displayed in green.
- For each cacheable object, the
Cache Directory and
Cache Name attributes are set in the
Caching attribute group of the object's main properties node.
- Enable is activated and
Cache Control is set to 1 (read mode).
- If desired, you can turn
Scratch Cache back on for faster scrubbing and playback.
Note: When using the cache, turn off
Run up to current time in your
Create a user cache for individual Bifröst objects
You can create a user cache for an individual Bifrost object by setting its
Caching attributes. Caching a single object reduces unnecessary computations when user caches of other objects in the simulation are not needed. This means that you need to recache the entire simulation if you extend its frame range.
Important: In your
preferences, make sure that
Looping is set to
Once. Otherwise, Bifröst re-caches the simulation when it loops back to the start frame.
- Select the main container for the simulation that you want to cache.
- In the
Attribute Editor, click the tab for the main properties node of the object you want to cache.
- In the object's Caching group, set
Cache Control to 2 (write mode).
Make sure that all other Caching attributes are set as desired. See
Bifröst Caching attributes.
- Play the simulation from the start frame to create the user cache.
Bifröst computes and caches frames for the object and saves them to the specified location.
- Set the
Cache Control to 1 (read mode).
- Preview the simulation.
Stop reading from a user cache
- Rewind the simulation to the start frame.
- Turn off
Enable in the Bifröst object's
Caching attribute group of its main properties node.
Cache Control remains set to 1 (read mode). However, Maya will compute the simulation rather than read the user cache.