Maniphest T76911

Mantaflow: Cache not invalidated when moving domain
Closed, Duplicate

Assigned To
None
Authored By
Andrea Coppola (blenderhighschool)
May 20 2020, 2:58 PM
Tags
  • BF Blender
  • Nodes & Physics
Subscribers
Andrea Coppola (blenderhighschool)
Germano Cavalcante (mano-wii)
Nikhil Shringarpurey (Nikhil.Net)
Sebastián Barschkis (sebbas)

Description

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce RTX 2080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 445.87

Blender Version
Broken: version: 2.83 (sub 17), branch: master, commit date: 2020-05-19 23:15, hash: rBdfe8195dfe83
Worked: (newest version of Blender that worked as expected)

Short description of error
Hi, In Blender 2.83 beta, can't bake the "Fluid" simulations. So, when I create a new domain, scaling it, the smoke stay in the original position. The same problem appears when I use Liquid similation. Scaling or moving Domain the particles scale and move but don't consider the original position of the flow object. Can't adjust it without bake? How to solve it? How to restart the simulation considering the new Domain dimension and position?

Exact steps for others to reproduce the error

  1. Create a liquid domain and an inflow object within it. Ensure the cache type is set to Replay.
  2. Set the domain to show as wireframe in the viewport so you can see the particles within it.
  3. Play 20-30 frames and observe particles behaving properly.
  4. Move the domain down on the Z axis while keeping the inflow object within it.
  5. Rewind to frame 1 and play again. Note that the fluid positions are still cached and calculated relative to the original domain position.

The only way to fix it is to set cache type to Final, start baking, then free all data, then go back to Replay cache type.

Event Timeline

Andrea Coppola (blenderhighschool) created this task.May 20 2020, 2:58 PM

Philipp Oeser (lichtwerk) added a project: Nodes & Physics.May 20 2020, 3:08 PM
Ankit Meel (ankitm) updated the task description.May 20 2020, 3:40 PM
Andrea Coppola (blenderhighschool) added a comment.May 20 2020, 3:53 PM

I wondered that, deleting the cache in the panel in Blender, the problem is solved and the particles or the smoke start correctly around the Flow object.
So, I think that this is non a friendly method.
It's OK to remove the Bake buttons and the real time simulations, but maybe you can add a "RESET CACHE" button?
Thanx!
Andrea

Germano Cavalcante (mano-wii) changed the task status from Needs Triage to Needs Information from User.May 21 2020, 11:21 PM
Germano Cavalcante (mano-wii) added a subscriber: Germano Cavalcante (mano-wii).

I don't understand the problem.
Could you provide a simple .blend file and describe the steps to reproduce the problem?

guideline for making bug reports: https://wiki.blender.org/wiki/Process/Bug_Reports

Nikhil Shringarpurey (Nikhil.Net) added a subscriber: Nikhil Shringarpurey (Nikhil.Net).EditedMay 22 2020, 5:25 PM

I can attach a blend file but I see what he is saying, and it is not related to Gas domains only - it also affects liquid domains. Here's what happens and I can replicate it 100% on 2.83 as of current build:

  1. Create a liquid domain and an inflow object within it. Ensure the cache type is set to Replay.
  2. Set the domain to show as wireframe in the viewport so you can see the particles within it.
  3. Play 20-30 frames and observe particles behaving properly.
  4. Move the domain down on the Z axis while keeping the inflow object within it.
  5. Rewind to frame 1 and play again. Note that the fluid positions are still cached and calculated relative to the original domain position.
  6. The only way to fix it is to set cache type to Final, start baking, then free all data, then go back to Replay cache type.

Some button or option to clear the replay cache is what OP is asking for, and I think that's a reasonable request. Or, the replay cache should reset at the start of playback at frame 1 if changes to the domain transform have occurred.

Currently, fiddling with domain settings and changing them back does force a cache reset, but that's not a clean way to handle this use case.

Andrea Coppola (blenderhighschool) added a comment.EditedMay 22 2020, 8:07 PM

Correct Nikhil.
I think that includIng into the final version 2.83 a reset button for the chache or force anyway the chache to reset automatically when restart the animation is a very reasonable solution.
Waiting.
Thank you

Germano Cavalcante (mano-wii) changed the task status from Needs Information from User to Needs Triage.May 22 2020, 8:23 PM
Nikhil Shringarpurey (Nikhil.Net) added a subscriber: Sebastián Barschkis (sebbas).EditedMay 22 2020, 8:55 PM

I wanted to tag @Sebastián Barschkis (sebbas) so he saw this, as he is one of the super-smart physics brains here! 😀

Sebastián,

Take a quick look at my comment above with steps to reproduce and I think you'll see right away what we are talking about.

Richard Antalik (ISS) renamed this task from Can't adjust the smoke simulation scaling domain in blender 2.83 beta to Mantaflow: Cache not invalidated when moving domain.May 25 2020, 11:46 AM
Richard Antalik (ISS) changed the task status from Needs Triage to Confirmed.
Richard Antalik (ISS) updated the task description.