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Technical Discussion » Air and bubbles again - no way for me
- rgoldade
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I would recommend enabling “Apply Moving Collisions”, use a “Min Air Region Voxels” of something like “5”. Without moving collisions, your bubbles are pulled along with the cup so holes open up. The Min Air Region allows small bubbles to collapse, so if bubbles do form along the cup as it's moving they can hopefully collapse back down. Finally, adding more substeps could help (although I still got decent results without changing the substeps).
Technical Discussion » Floating Geometry- flip fluids
- rgoldade
- 73 posts
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I took a look at the boat. It seems like the resolution of the flip simulation is not high enough to capture the boat. One thing to keep in mind is that the size of a voxel in the flip simulation is (particle separation) * (grid scale). If the canoe is not thicker than one or two voxels, it won't be accounted in the solver. A good way to check is to enable “Collision” in the Guides->Visualization tab in the FLIP Object node. It will show a purple mesh of the collision volume.
I had to decrease the particle separation to .025 before I could even see the canoe show up as a collision. I imagine you will need to make it much smaller for the sides of the canoe to show up. This will definitely take longer to simulate so it might be preferable to reduce the size of the tank that you're using.
I had to decrease the particle separation to .025 before I could even see the canoe show up as a collision. I imagine you will need to make it much smaller for the sides of the canoe to show up. This will definitely take longer to simulate so it might be preferable to reduce the size of the tank that you're using.
Technical Discussion » Floating Geometry- flip fluids
- rgoldade
- 73 posts
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Are you using the same rigid body option for the boat as the torus? Also, how thick is your boat? If the shell of the boat is too thin, then the flip solver might not realise the boat as a collision (depending on the particle separation of course).
Technical Discussion » Floating Geometry- flip fluids
- rgoldade
- 73 posts
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Hello! I tried to run the float.hipnc file and the torus falls and floats on top of the fluid properly. I can't seem to recreate this problem.
Technical Discussion » Fluid densities
- rgoldade
- 73 posts
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In the FLIP solver->Volume Motion->Density tab there will be an option that says “Density by Attribute”. This will allow you to set the density per-particle. You can then set the densities as needed with a POP Wrangle.
I would recommend watching some of the fluids masterclasses to help get comfortable using some of these tools.
I would recommend watching some of the fluids masterclasses to help get comfortable using some of these tools.
Technical Discussion » Air and bubbles again - no way for me
- rgoldade
- 73 posts
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Hi,
It looks like things weren't working because the resolutions were too low. I decreased the particle separation in the flip simulation and decreased the division size of the sink. I then got the sink bubble that you were looking for. It will likely be difficult to do without losing water. One approach to correct this is to apply divergence to the fluid to help it expand and make up for the lost liquid. You will likely find that your bubbles change volume as well. I've found that using the “Detect droplets” feature with “kill at fluid” can help reduce volume loss with bubbles.
I hope that helps,
Ryan
It looks like things weren't working because the resolutions were too low. I decreased the particle separation in the flip simulation and decreased the division size of the sink. I then got the sink bubble that you were looking for. It will likely be difficult to do without losing water. One approach to correct this is to apply divergence to the fluid to help it expand and make up for the lost liquid. You will likely find that your bubbles change volume as well. I've found that using the “Detect droplets” feature with “kill at fluid” can help reduce volume loss with bubbles.
I hope that helps,
Ryan
Technical Discussion » FLIP Solver flow rate
- rgoldade
- 73 posts
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Have you tried to overwrite the velocity of the fluid in and around your emitter? This way the fluid can only flow out at (mostly) a fixed rate.
Houdini Indie and Apprentice » FLIP fluid passing through a RBD Fractured object
- rgoldade
- 73 posts
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You might need to increase substeps in the flip solver. It also looks like your fluid is pretty low res and doesn't initially fill the cup. It might be difficult to match the movement of the cup this way.
Houdini Indie and Apprentice » Flat Tank wont load - What's wrong with my FBX?
- rgoldade
- 73 posts
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Hi,
We've filed it as a bug. Fortunately there is a work around. Create a new geo node and place an object merge node inside. Then reference your desired follow object with the object merge. Now you can use your new geo as the follow selection for the flat tank.
I've attached a modified version of your example.
I hope that helps,
Ryan
We've filed it as a bug. Fortunately there is a work around. Create a new geo node and place an object merge node inside. Then reference your desired follow object with the object merge. Now you can use your new geo as the follow selection for the flat tank.
I've attached a modified version of your example.
I hope that helps,
Ryan
Edited by rgoldade - Nov. 20, 2017 12:08:24
Houdini Indie and Apprentice » Flat Tank wont load - What's wrong with my FBX?
- rgoldade
- 73 posts
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Hi!
Thank for including an example file. I was able to reproduce the issue and it looks like this is a bug. Please be patient while we look into it.
Thank you,
Ryan
Thank for including an example file. I was able to reproduce the issue and it looks like this is a bug. Please be patient while we look into it.
Thank you,
Ryan
Technical Discussion » Flip Fluid Tank and Ball
- rgoldade
- 73 posts
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Hello,
I would be happy to try and help. Would you be able to post the .hip file so we can take a look at what you're experiencing?
Take care,
Ryan
I would be happy to try and help. Would you be able to post the .hip file so we can take a look at what you're experiencing?
Take care,
Ryan
Work in Progress » Houdini 16.5 - Fluid NarrowBand simulation
- rgoldade
- 73 posts
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Technical Discussion » FLIP fluid friction values
- rgoldade
- 73 posts
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Have you tried using the “stick on collision” option in the FLIP solver? It might give you better control.
Technical Discussion » Velocity Variance with Flip Fluids
- rgoldade
- 73 posts
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Technical Discussion » Mud spewing
- rgoldade
- 73 posts
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Hi,
The liquid part of the mud should be achievable with the right viscosity + density settings. You might have to experiment with the sludge component however. Since it doesn't really behave like a fluid you might need to use grains.
Good luck,
Ryan
The liquid part of the mud should be achievable with the right viscosity + density settings. You might have to experiment with the sludge component however. Since it doesn't really behave like a fluid you might need to use grains.
Good luck,
Ryan
Houdini Lounge » Houdini 16 - Flip Fluid Upresing ?
- rgoldade
- 73 posts
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Are you able to provide an example file? I would be happy to take a look and offer some help.
Houdini Indie and Apprentice » Surface Tension - Multiple Flip Solvers?
- rgoldade
- 73 posts
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Hi,
Surface tension is applied through a field named “surfacepressure”. You can manually modify this field through the “Volume Velocity” input in the flipsolver.
For example, you could set an attribute on the particles to represent surface tension. Then use Gas Particle to Field to bring it into a field context and then scale the surfacepressure field by this newly created field. This will give the droplet and the tank different surface tension strengths. However once your droplet collides with the water in the tank, you will end up with a strange blend of surface tension strengths.
Hope that helps,
Ryan
Surface tension is applied through a field named “surfacepressure”. You can manually modify this field through the “Volume Velocity” input in the flipsolver.
For example, you could set an attribute on the particles to represent surface tension. Then use Gas Particle to Field to bring it into a field context and then scale the surfacepressure field by this newly created field. This will give the droplet and the tank different surface tension strengths. However once your droplet collides with the water in the tank, you will end up with a strange blend of surface tension strengths.
Hope that helps,
Ryan
Technical Discussion » Boat moving across ocean simulation
- rgoldade
- 73 posts
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It's possible that the particle sourcing step to maintain fluid in the guided layer is putting particles inside the boat. Try increasing the “Layer Size” in the Ocean Source.
Edited by rgoldade - July 7, 2017 10:15:54
Technical Discussion » FLIP Waterline Trouble
- rgoldade
- 73 posts
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Hi,
Can you post the .hip file? I wasn't able to recreate your problem.
To test I set up a scene with a FLIP Tank, an emitter and a keyframed waterline. In this example, the water level rose in accordance with the waterline plane.
Ryan
Can you post the .hip file? I wasn't able to recreate your problem.
To test I set up a scene with a FLIP Tank, an emitter and a keyframed waterline. In this example, the water level rose in accordance with the waterline plane.
Ryan
Technical Discussion » guidedoceanlayer caching
- rgoldade
- 73 posts
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Hi,
I'm happy to take a look at this issue. Can you include the .hip file so I can recreate the problem?
Thanks,
Ryan
I'm happy to take a look at this issue. Can you include the .hip file so I can recreate the problem?
Thanks,
Ryan
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