Page MenuHome

Fieldweights Gravity doesn't work with Mantaflow Liquid
Closed, ResolvedPublicBUG

Description

System Information
Operating system: Windows-10-10.0.17763-SP0 64 Bits
Graphics card: Intel(R) HD Graphics 630 Intel 4.5.0 - Build 25.20.100.6472

Blender Version
Broken: version: 2.83 (sub 7), branch: master, commit date: 2020-03-10 12:11, hash: rB85cdf9a1b9e8
Worked: Never

Short description of error
Sliding the gravity slider all the wy to zero doesn't effect the simulation.

Exact steps for others to reproduce the error

Open a fresh Blender scene and delete everything. Add a sphere. With sphere selected choose "objects"->"quick effects"->"quick liquid".
In the physics properties go down to field weights and set the gravity slider to zero.
Bake the data and the mesh (if you like to).
Fluid is falling down to the "ground" allthough gravity has to have no influence to the simulation.

Event Timeline

Ankit (ankitm) changed the task status from Needs Triage to Needs Information from User.Wed, Mar 11, 12:26 PM
Ankit (ankitm) added a subscriber: Ankit (ankitm).

there are some reports about this.. please check if it is similar to one of :

https://developer.blender.org/T73680
https://developer.blender.org/T73474
https://developer.blender.org/T72949

It would help if you also provide a simple blend file.

T73680 is not using scene gravity (scene properties -> no checkmark at "gravity") but using the gravity settings inside Mantaflow. Also it says that using this property the gravity is 10 times stronger...
T73474 is a bug report concerning real word size setting...
T72949 mentions the initial velocity not to be used by the Mantaflow emission object...

Maybe all bug reports refer to the same basic problem, but each report describes a different but incorrect behavior of Mantaflow.

I also provided a .blend. Please open it and bake the data (not provided).

Ankit (ankitm) changed the task status from Needs Information from User to Needs Triage.Tue, Mar 17, 9:29 AM
Ankit (ankitm) added a comment.EditedTue, Mar 17, 10:21 AM

The report seems correct. scene gravity is working as expected, but global property is always downwards despite changing slider values. https://docs.blender.org/manual/en/latest/physics/forces/gravity.html says

Changing this value would simulate a lower or higher force of gravity. Gravity denoted g, measurement m × s-2.

Richard Antalik (ISS) changed the task status from Needs Triage to Confirmed.Tue, Mar 17, 12:19 PM
Richard Antalik (ISS) updated the task description. (Show Details)