Fluid baking doesn't work on dynamically created objects #72291

New Issue

Mike · 2019-12-09T09:21:22+01:00

Mike commented

2019-12-09 09:21:22 +01:00

Blender Version
Broken: 2.81, released

Short description of error
Fluid simulation does not work on instanced objects. It ignores all objects that don't exist in frame zero.

Exact steps for others to reproduce the error
Create a fluid sim that works. Create an instanced object with fluid inflow. No fluid flows from it.
Create an instanced object with fluid modifier "Fluid". Does not generate associated fluid. Object with Fluid modifier "fluid" is visibly created, but the fluid itself isn't.

Fixing this allows for actual dynamic rain simulation.

**Blender Version** Broken: 2.81, released **Short description of error** Fluid simulation does not work on instanced objects. It ignores all objects that don't exist in frame zero. **Exact steps for others to reproduce the error** Create a fluid sim that works. Create an instanced object with fluid inflow. No fluid flows from it. Create an instanced object with fluid modifier "Fluid". Does not generate associated fluid. Object with Fluid modifier "fluid" is visibly created, but the fluid itself isn't. Fixing this allows for actual dynamic rain simulation.

Mike commented

2019-12-09 09:21:22 +01:00

Added subscriber: @MMMM

Stephen Swaney commented

2019-12-10 00:39:14 +01:00

Added subscriber: @StephenSwaney

Stephen Swaney commented

2019-12-10 00:39:14 +01:00

Got a .blend for us?

Mike commented

2019-12-10 01:08:09 +01:00

Fluid Bug.blend
You'll need Animation nodes enabled.
You can see the base object works, the object instanced in frame 0 works, all objects instanced after that do not produce liquid.
(Note, in animation nodes I have all spawns objects to be hidden, just as you would all fluid objects.)

Also, particles as objects don't inherit fluid property. As you can see they don't work as fluid even in frame zero. I looked at the base code, and it appears that passing this inheritance would be a simple fix. (Since you inherit other attributes of the base object already)

[Fluid Bug.blend](https://archive.blender.org/developer/F8203469/Fluid_Bug.blend) You'll need Animation nodes enabled. You can see the base object works, the object instanced in frame 0 works, all objects instanced after that do not produce liquid. (Note, in animation nodes I have all spawns objects to be hidden, just as you would all fluid objects.) Also, particles as objects don't inherit fluid property. As you can see they don't work as fluid even in frame zero. I looked at the base code, and it appears that passing this inheritance would be a simple fix. (Since you inherit other attributes of the base object already)

Mike commented

2019-12-10 01:12:38 +01:00

Also, it'd be nice if the particle as objects inherited the "hidden" if they inherit "fluid". That way they produce water to be simulated not 'physical' objects nor actual particles that die.

Germano Cavalcante commented

2019-12-17 13:32:17 +01:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2019-12-17 13:32:17 +01:00

A big fluid refactor of was made recently.
It's now a new system called mantaflow.
Can you try on a recent build? https://builder.blender.org/download/

A big fluid refactor of was made recently. It's now a new system called mantaflow. Can you try on a recent build? https://builder.blender.org/download/

Mike commented

2019-12-18 16:38:10 +01:00

It's actually worse in the most recent:
"Baking Data" in the fluid breaks Animation nodes.
If you bake animation nodes first then try to bake fluid, Blender crashes.

It's actually worse in the most recent: "Baking Data" in the fluid breaks Animation nodes. If you bake animation nodes first then try to bake fluid, Blender crashes.

Mike commented

2019-12-18 16:45:06 +01:00

Also, the Z axis is backwards for the new manta flow... everything "falls" up. ^_^

Germano Cavalcante commented

2019-12-18 17:34:46 +01:00

Animation Nodes is not an official blender addon and is getting deprecated as it will be replaced by a builtin system in blender.
To address the issue you need to describe steps that do not involve installing unofficial addons.

Animation Nodes is not an official blender addon and is getting deprecated as it will be replaced by a builtin system in blender. To address the issue you need to describe steps that do not involve installing unofficial addons.

Mike commented

2019-12-19 04:01:04 +01:00

I know of no other way to spawn an item on a frame other than first frame. Are there any official ways to make an item (or exact copy of another item) spawn into existence? Particle system doesn't carry over "fluid" properties. (Which I've submitted as a feature request.)

Germano Cavalcante commented

2020-01-03 15:31:51 +01:00

Changed status from 'Needs User Info' to: 'Archived'

Germano Cavalcante closed this issue

2020-01-03 15:31:51 +01:00

Germano Cavalcante self-assigned this 2020-01-03 15:31:51 +01:00

Germano Cavalcante commented

2020-01-03 15:31:51 +01:00

If we can't reproduce the problem using the official features available in Blender, there is not much we can do.
If you think you found a bug, please submit a new report and give us more clear instructions on how to reproduce it from scratch.

If we can't reproduce the problem using the official features available in Blender, there is not much we can do. If you think you found a bug, please submit a new report and give us more clear instructions on how to reproduce it from scratch.

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Fluid baking doesn't work on dynamically created objects #72291