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Homer0

How to resume a Flip simulation

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Hi all, i'm just starting to learn Houdini and diving into some Flip simulations; but i encountered a little problem.

I found that to cache my simulation i can save the sequence of .bgeo files throught the Import node of ParticleFluid, but let's say i have a very long simulation, how can i run half of it, then stop and finish it in another moment?
 I found some information about a .sim file, but in Houdini 15 there's no such thing like "Explicit Cache" (probably the command is changed). And more important, with these .sim file, houdini does save the simulation as well the particles?

Also, a (probably silly) question: when i import the .bgeo cache in a new scene, it's all grey, with no point coloration based on the velocity; but when i create a digital asset from that cache and i import it in maya with houdini engine, the velocity color comes back. Any change to enable that color in the .bgeo chace in houdini?

Thanks in advance ^^

Edited by Homer0
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I havent got into FLIP yet but for pyro there is a save checkpoints option on your sim node that writes .sim files that you then load into the initial state to resume from there. May be the same for flip

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In dops Under cache tab u have an option to save checkpoints(.sim files) and you can specify the interval to save checkpoints. In simulation tab u can load the initial state.If this causes problems u can use file node inside dops mention the path,set it to write and in activation u can specify the interval to activate(Ex:$F%50==1)  and load it in intial state tab. To visualize velocity u can find the speed of velocity(length) and call the attribute into color from attribute.

visspeed.hip

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awesome thanks ^^

Another couple of questions:

-In my last test, i saved my particle cache as .bgeo files, then loaded and used to simulate the Whitewater. As a third step i simulated the Surface. For hdd space purpose (the particles cache took about 300gb), can i directly simulate the surface bypassing the particles and use it to simulate the Whitewater?

-In the file attached i've some emitter falling down after a light collision with a mesh and colliding with a Ocean Waves floor. I'm pretty satisfied from the motion and all, but i noticed there are too many splashes after the collision with the floor. I know that since the scale is big (34 meters height) the behaviour is pretty realistic, but i have to get rid of those for artistic purpose. I tried with a Pop Drag node but it kills me the fluid internal movement completely... also tried to 0 the bounce value of the floor but seems that doesn't count for Flip...

 

splash.jpg

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if i may, other case - if simulation flip or whitewater crashed during the write .sim sequence, is possible to read unfinished sequence and continue?

i cannot read to autodop or fluid network broken sequence...seems [out node] dont recognize .sim files ...(?

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16 hours ago, kaumanawardze said:

if i may, other case - if simulation flip or whitewater crashed during the write .sim sequence, is possible to read unfinished sequence and continue?

i cannot read to autodop or fluid network broken sequence...seems [out node] dont recognize .sim files ...(?

i'm confused, if you .sim sequence crashed for example at frame 50, the corrupted file shoul be only the last frame, so by loading the cache 1-49 should be fine...

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yes, your`re right, something with my project, houdini tried to reach broken frame and crashing everytime... mayby some performance problem. I change my question - is possible to kick houdini to jump last frame faster lets say to 49frame instead reading simulation everytime from beggining? For comparison Maya has diffrent cache method- just jump & read specific frame, houdini "likes" reading everytime from beggining. thanks!

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3 hours ago, kaumanawardze said:

yes, your`re right, something with my project, houdini tried to reach broken frame and crashing everytime... mayby some performance problem. I change my question - is possible to kick houdini to jump last frame faster lets say to 49frame instead reading simulation everytime from beggining? For comparison Maya has diffrent cache method- just jump & read specific frame, houdini "likes" reading everytime from beggining. thanks!

I tried to create a simple sphere emitting some fluid. If i enable Save Checkpoint and generate my .sim sequence (let's say to frame 49), then i can scrubs between 1 and 49 with no Cook time.

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