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ekan de

Bottle pour into glass.

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Beginner houdini user here. Trying to learn small scale simulations has been a struggle so far. It's been far from a logical journey so far i must say.

The simulation i am working on is a bottle of beer poured into a glass and then the bottle is set down on again.

With lots of iterations i have managed to get the first state of the pour to a good look i think. however i know want to set the bottle down again and that is when things start to get funky.

The flip particles seems to increase in velocity when moving the bottle back and down again, resulting in them spraying out in control upwards.

I have no idea what is going on and why, been trying different settings for quite some time now so if someone has a pointer in the right direction that would be awesome!

 

Attaching a compressed scene file with all the geo and also a flipbook of it.

beerpour.rar

beerpour_v008.mov

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Well for starters your gravity scale is way off, I'd recommend working at a 1 unit = 1 meter scale.

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14 hours ago, Aragatory said:

Well for starters your gravity scale is way off, I'd recommend working at a 1 unit = 1 meter scale.

I have tested different scales to no avail.

Tested to go the 1unit 1 meter scale but that gives me a sim that is very unstable.

I can ofcourse do another testrun to check it once again.

And even if the the scale was off, why would the particles go upwards?

 

Starting a sim with another scale now to see how it behaves.

 

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So. tested to scale it down and even thou the sim takes time to go thru i get no particles at all.

Will take a look at the link sepu submitted and see if i can find something.

 

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On 1/27/2018 at 3:30 AM, ekan de said:

I have tested different scales to no avail.

Tested to go the 1unit 1 meter scale but that gives me a sim that is very unstable.

I can ofcourse do another testrun to check it once again.

And even if the the scale was off, why would the particles go upwards?

 

Starting a sim with another scale now to see how it behaves.

 

Well I feel like they were going upwards because of centrifugal force and the gravity effectingthem being relatively small due to scale. But I could be wrong. 

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So i have tested sims in different scales now. they all give the same result with the particles going upwards when i take away the bottle. a little would have been fine but them going 10 cm over the bottle when the bottle is going down seems weird.

I did test the pour in real life. measuring how long it would take to empty the bottle and see how it behaves when putting it down. the motion when putting the bottle down is fairly quick.  Did a test with a slower version but that didnt help much.

 

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Ekan, there are a bunch of issues with your setup, but I don't think scene scale is the main issue. 

I'd try matching the pour motion and speed with a real bottle, my guess is you'll make a big mess! :)  You'll need a lot of substeps as your bottle/glass are very thin, and the fluid will still go flying when the bottle flips back.

Your sim is also really slow as it's rebuilding very high res collision volumes for the bottle/cup on every frame (deforming is on). I'd apply your motion at object level so that you only need to build the collision SDF once at the beginning. Cup is static as well, so no need for the deforming flag to be enabled as that really slows things down! This is an instance where using the collision shelf tools is great for getting something that works well for most scenes with minimal tweaking.

Will post a tweaked version of your scene with more notes if you still need help!

--Dave

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Thank you for the input Dave. im in the middle of selling my appartment so havent been able to spend any time on the scene. will have a look at the suggestions you made and come back.

 

Sidenote: i did take a bottle and fill it and took the time when i poured it into a glass. However i kinda just eyballed the timing on when the bottle goes back to the ground when the pour is done.

Thanks again for the input!

 

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