Fluid will just not bake sometimes

I came across many threads on this topic but no solution.

I’m using Blender 2.70 on Linux, sometimes when I bake the fluid domain, only the first frame gets baked and not the rest, and sometimes no frames at all get baked.

I tried all sorts of resolution and time settings, low, high. The progress bar appears at the top for a minute and seems like its baking but then the progress bar goes away and the domain object is still a cube.

I also tried deleting the cache, changing the cache name, even resetting the fluid objects but just for some reason or randomly the fluid domain just will not bake.

Has any else come across a solution to this problem?

I have experienced similar problems on Windows 7. It always seems to have something to do with the cache path. By default Blender uses Relative Pathing and this can be set to Absolute pathing in the User Preferences. Under the File TAB disable Save & Load Relative Paths. This is one of my personal default that I change each time I get a new copy of Blender. Try changing the pathing method on Linux and see if that helps. Blender expects to have write permission access to the cache path as well.

When in doubt, I will throw away all fluid elements or start with a brand new scene and rebuild the fluid sim from scratch.

Also I recently had a hard disk go bad. Blender was having strange problems that did not make sense because it was denied access to bad sectors that resided in folders that Blender should have had access to. This made Blender internally think it was a permissions issue but the disk was really just bad.

If you have not done a check disk in a while that might be worth running overnight just to be sure.

No good :frowning: I tried using /tmp/cache_fluid_89234 and other absolute paths with random names trying to get Blender to re-bake everything but it still will not.

After a while or a couple of tries at bake, the fluid domain will not bake at all (no frames will bake, it remains a rectangle on all frames).

I tried this on a brand new scene, an icosphere set to inflow and a plane below it as an outflow, then I use quick fluid.

Sometimes the first time around it will bake, but the second or third it will never bake.

Deleting the cache does not work.

Changing the path of the fluid domain’s cache does not work (even on absolute paths).

I tried this on a couple versions of blender; 2.70, 2.71, 2.63, it’s always the same problem.

I’m absolutely sure it’s a bug, ad perhaps a simple one where Blender just won’t clear a cache.

I’m not sure exactly how to file a bug or where to file a bug for Blender though.

EDIT:

I tried baking fluid on Mac with Blender 2.70, it’s basically the same problem.

The first time it bakes a few frames, then subsequently it bakes fewer and fewer frames until it bakes none and you only see the fluid domain cube as a cube on all frames.

No matter how low or high the resolution, it just won’t bake, the progress bar does show for a short period but then goes away as if it was done baking.

I seriously think this is a bug.

I get that frequently on Windows. Sometimes deleting Inflow or Domain objects and replacing them will help. Slightly tweaking the sizes and/or the settings on either object has cleared it up for me too. But keep an eye on the Bake Memory if you resize your Domain. If it goes up a significant amount, you may want to build a new one. I wish there were definite solutions for these kinds of bugs, but I haven’t found any.

I have been at this for many hours and pretty exhausted.

I have tried every thing that I could think of, including creating new blends with simple inflow and fluid domain objects, still the problem is always there. Occasionally a new scene will bake the first few frames but not the rest.

I have tried this with Blender on PC and Mac with the same problem.

The most memory the bake ever uses is about 70MB, a fraction of what of my computer’s available real memory.

I think it’s a bug in which Blender just won’t clear some kind of reference that it has to an old cache that no longer exists yet it still thinks it exists somewhere.

I’m pretty close to abandoning fluid in Blender for now. X.X

Here is a chopped down new scene I created from the one I was having problem, it also does not bake for me.

If anyone can get this fluid to bake on this scene please let me know, I would greatly appreciate it. :slight_smile:

fluid_example.blend.zip (450 KB)

After looking at your Blend I do see a mistake. You have non-applied scaled for your Domain and Inflows. You need to apply the scale. The domain needs to have a scale of 1.0 for x,y,z. So clear the scale (ALT-S) put the cube in edit mode and scale up the vertices instead of scaling the object. Also 10 meters for world size often produces no action because the body of water is evaluated as more static than in motion. Try setting world size to 1.0 instead.

With the above changes, and specifying a valid cache path on my drive the bake works.

I got a lot out of watching this tutorial on how to use the fluid sim.

Thanks! Ah okay, so the problem was that the scale of the fluid domain object must be 1.0 and its veriticies (in edit mode) define its bounds?

I should note that the fluid domain was automatically created by the Quick Fluid function under the Object menu. Maybe that is where the bug is? I basically selected all my inflow fluid objects and went to Object->Quick Fluid.

It automatically creates the fluid domain cube (wrong?).

The size of domain is about 10m in real life, are you saying that is too big? I did model everything up to scale.

I managed to get something rendered, here is a snapshot of the stream up close rendered with the fluid domain’s resolution set at 250 and the real world size at 10m. Should I make the real world size smaller?



Please let me know what you think, I feel that the surface tension is a bit too strong as the water forms beads and large rounded edges.

I set the fluid domain object’s material to Mirror 0.3 and its reflecting Fresnel to 4.0.

Adding to what Atom said, I think everything used in the fluid sim is supposed to have a scale of 1. I had a lot of issues with fluid being out of scale with the obstacles when I first started, and setting the scale of all objects to 1 fixed it.

I believe I have found the bug with your help, it seems that “Quick Fluid” is the problem (it has a bug).

It automatically generates a fluid domain cube and scales the object to something other than 1.0, not its mesh verticies to encompass the fluid objects. In other words, it has a scale other than 1.0 and that messes everything up.

If I use “Quick Fluid” and then manually fix the domain cube that it generates to a scale of 1.0 and edit its mesh, then the fluid domain bakes.

Good to know, that should be reported as a bug. I have never used any of those “quick” solutions.

Yeah when I was learning smoke/fire, the tutorial said to use the “Quick Smoke” and then I tweaked the values from there.

So I figured I do the same for fluid, but I never read anywhere online about fluid needing every fluid object scaled to 1.0.

I’m still not understanding the Real World Size either, I’ve tried adjusting it to larger values and smaller values but my fluid still looks like giant beads (as if it was a closeup of fluid in a cup or a splatter on a table. I have 5 meter lone pond/river and so I need fluid to look more flat and less surface tension.

Any ideas?