Learn about load simulation from a disk, and disabling and re-writing a cache.
- [Narrator] In this movie we'll look at reading, disabling, and rewriting a Bifrost user cache. Before saving a scene that references a cache, it's a good idea to rewind to the beginning of the timeline before the simulation start frame. That way Mya will not need to access the cache when the file first loads. We can control when that access happens. In this case we can press the play button. The cache gets loaded in when the timeline reaches the first frame of the simulation.
It may take a moment to load the entire cache because in this case it's 15 gigabytes. But once it's loaded, the cached frame range appears in blue when we select the Bifrost liquid solver or our liquid properties node. I'll select one of those, and the cached frame range is displayed in blue. We can press stop. At this point we could build a play blast if we wanted to. We also need to talk about how to make changes to the simulation. Maybe we make a play blast and we don't like what we see.
To make changes we need to disable the cache. If you look in the Bifrost fluids menu, there's no menu item for that. Caching is handled by the liquid properties container. Let's rewind to the beginning of the simulation and select Bifrost liquid properties one and open the attributes. We should be taken to Bifrost liquid properties container one. Scroll down.
We've got a section for caching. It's got four subsections. We have liquid cache, solid cache, mesh cache, and initial state cash. We'll get to those last two later, close those back up, because this level set only has a liquid for the voxels and the particles, and it has a solid cache for the collisions.
We can see that the cache directory is listed here. If we wanted to point to a different cache, it would be a simple matter to just type that in here or copy and paste it. To make changes to the simulation, first disable the relevant caches. Then make the adjustments in the scene and rewrite the caches from the same menu item, Bifrost fluids, compute and cached disc options. I recommend always going into the options and checking them. If we wish, we can overwrite the existing cache or we can specify a new file directory here.
We're not actually going to do this. I'm going to close the compute and cash options dialog. The cash enable switches are turned back on automatically as soon as we initiate a new cache write operation. That's how to read, disable, and rewrite a user cache. I'll reenable these, and now we're ready to to move on to meshing.
- Bifröst basics
- Analyzing the node structure
- Emitting from a polygon mesh
- Colliding with a polygon mesh
- Adding velocity, friction, and drag with motion fields
- Optimizing space and time accuracy
- Caching simulations
- Meshing and exporting liquids
- Render-time meshing in Arnold
- Applying channel data to Arnold shaders
- Generating foam from a liquid
- Rendering and shading foam in Arnold