Wrong location of FLIP fluid mesh after editing domain mesh #73979

New Issue

MARaf · 2020-02-18T18:41:17+01:00

MARaf commented

2020-02-18 18:41:17 +01:00

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 1070 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 436.30

Blender Version
Broken: version: 2.82 (sub 7), branch: master, commit date: 2020-02-12 16:20, hash: 77d23b0bd7
Worked: (optional)

Short description of error

Any time I make any simple scene with FLIP fluids and bake the mesh, it ends up bellow the actual fluid simulation. Moving it manually isn't helpful as it moves the particles along with it. I managed to get it to work only once by changing the cache folder. For some reason it worked then, but now I've tried about 5 times and made several different scenes, I always get the same result.

Exact steps for others to reproduce the error

Create any fluid simulation, either manually or with quick fluid
Select Domain, go to edit mode, move one of faces
bake the simulation
bake the mesh

{F8348391}Flip fluid bug.blend

**System Information** Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: GeForce GTX 1070 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 436.30 **Blender Version** Broken: version: 2.82 (sub 7), branch: master, commit date: 2020-02-12 16:20, hash: `77d23b0bd7` Worked: (optional) **Short description of error** Any time I make any simple scene with FLIP fluids and bake the mesh, it ends up bellow the actual fluid simulation. Moving it manually isn't helpful as it moves the particles along with it. I managed to get it to work only once by changing the cache folder. For some reason it worked then, but now I've tried about 5 times and made several different scenes, I always get the same result. **Exact steps for others to reproduce the error** - Create any fluid simulation, either manually or with quick fluid - Select Domain, go to edit mode, move one of faces - bake the simulation - bake the mesh {[F8348391](https://archive.blender.org/developer/F8348391/unknown.png)}[Flip fluid bug.blend](https://archive.blender.org/developer/F8348387/Flip_fluid_bug.blend)

MARaf commented

2020-02-18 18:41:17 +01:00

Added subscriber: @PirateKitty

Richard Antalik commented

2020-02-19 13:59:17 +01:00

Added subscriber: @iss

Richard Antalik commented

2020-02-19 13:59:17 +01:00

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

Richard Antalik commented

2020-02-19 13:59:17 +01:00

Can you check if this happens when you load factory defaults (File > Defaults > Load Factory Settings)?
Does this happen when you apply Object > Quick Effects > Quick Liquid on default cube?

Can you check if this happens when you load factory defaults (File > Defaults > Load Factory Settings)? Does this happen when you apply Object > Quick Effects > Quick Liquid on default cube?

MARaf commented

2020-02-19 14:49:34 +01:00

Quick effects on the default cube worked as expected.
Then I changed the scene in edit mode to be like this:

And this happened:

I applied all transforms to the domain, things moved a bit, but were still off:

After that I loaded factory settings.
Default cube with quick liquid worked as expected. Scaling and moving the cube inside the domain quick liquid created worked as expected.
But after I edited the domain, the same as above happened and the mesh was off place again.

Edit:
Made a video as well, here's the link
https://www.youtube.com/watch?v=-Wg4SrKBr7k

Edit2:
I may have figured it out, same scene from the video after setting origin to geometry:

Quick effects on the default cube worked as expected. Then I changed the scene in edit mode to be like this: ![unknown.png](https://archive.blender.org/developer/F8350635/unknown.png) And this happened: ![unknown.png](https://archive.blender.org/developer/F8350639/unknown.png) I applied all transforms to the domain, things moved a bit, but were still off: ![unknown.png](https://archive.blender.org/developer/F8350644/unknown.png) After that I loaded factory settings. Default cube with quick liquid worked as expected. Scaling and moving the cube inside the domain quick liquid created worked as expected. But after I edited the domain, the same as above happened and the mesh was off place again. Edit: Made a video as well, here's the link https://www.youtube.com/watch?v=-Wg4SrKBr7k Edit2: I may have figured it out, same scene from the video after setting origin to geometry: ![unknown.png](https://archive.blender.org/developer/F8350698/unknown.png)

Richard Antalik changed title from ~~FLIP fluid mesh baking always ends in the wrong position~~ to Wrong location of FLIP fluid mesh after editing domain mesh

2020-02-19 15:07:28 +01:00

Richard Antalik commented

2020-02-19 15:08:02 +01:00

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

ronan ducluzeau commented

2020-02-19 15:10:43 +01:00

Added subscriber: @zeauro

ronan ducluzeau commented

2020-02-19 15:10:43 +01:00

When you edit domain to elongate it on one axis, origin of domain is no more at center of bounding box.

If you reset origin of domain to center of geometry (Object menu -> Set Origin ->Origin to Geometry) , everything should go back to expected position.

When you edit domain to elongate it on one axis, origin of domain is no more at center of bounding box. If you reset origin of domain to center of geometry (Object menu -> Set Origin ->Origin to Geometry) , everything should go back to expected position.

MARaf commented

2020-02-19 15:16:59 +01:00

In #73979#876134, @zeauro wrote:
When you edit domain to elongate it on one axis, origin of domain is no more at center of bounding box.

If you reset origin of domain to center of geometry (Object menu -> Set Origin ->Origin to Geometry) , everything should go back to expected position.

Yes, I just realized that. At least that's a quick fix for me to continue with my planned scenes. Considering the rest of the baking works regardless of the origin position, I believe mesh baking should as well.

> In #73979#876134, @zeauro wrote: > When you edit domain to elongate it on one axis, origin of domain is no more at center of bounding box. > > If you reset origin of domain to center of geometry (Object menu -> Set Origin ->Origin to Geometry) , everything should go back to expected position. Yes, I just realized that. At least that's a quick fix for me to continue with my planned scenes. Considering the rest of the baking works regardless of the origin position, I believe mesh baking should as well.

ronan ducluzeau commented

2020-02-19 15:47:13 +01:00

Globally, particles are relative to original mesh. But mesh result from simulation is replacing original mesh.
So, it has to be relative to origin.

There is probably a way to store point of reference of simulation when baking it to bake whatever origin is.
But you would have revert problem.

If for some reason, you reset origin of domain (selected as one object among others) ; you will recreate the offset.
And behavior will seem counter-intuitive in that case, too.
So, if there are few statement to respect, Domain is bounding box of current mesh. Origin of domain has to be in center of its bounding box.
We keep things simple and understandable by everybody.

Adding this explanation to documentation should be sufficient.

Globally, particles are relative to original mesh. But mesh result from simulation is replacing original mesh. So, it has to be relative to origin. There is probably a way to store point of reference of simulation when baking it to bake whatever origin is. But you would have revert problem. If for some reason, you reset origin of domain (selected as one object among others) ; you will recreate the offset. And behavior will seem counter-intuitive in that case, too. So, if there are few statement to respect, Domain is bounding box of current mesh. Origin of domain has to be in center of its bounding box. We keep things simple and understandable by everybody. Adding this explanation to documentation should be sufficient.

MARaf commented

2020-02-19 16:21:23 +01:00

When trying to convert coworkers from 3DSMax to Blender, I've seen two of them ragequit because of minor issues like this. At the time it was because of particle systems and setting more particles than vertexes when using that mode outright made blender crash out. It's something that could have been fixed with a simple IF statement in the code.

If this is intended behavior, that's alright, but it's an unintuitive behavior. When you set a domain, you expect things to work. At the very least make it clear, in the UI, in blender, that you have to set origin to geometry on the domain when baking instead of making the user think he's doing something wrong, then ask around, then maybe dig in the documentation to find out why.

Alternatively, you can just add a checkbox like "Set origin to geometry when baking" in the mesh baker menu. All it would have to do is run that function before doing the baking. Behavior remains the same and it's more user friendly with a minor automation.

When trying to convert coworkers from 3DSMax to Blender, I've seen two of them ragequit because of minor issues like this. At the time it was because of particle systems and setting more particles than vertexes when using that mode outright made blender crash out. It's something that could have been fixed with a simple IF statement in the code. If this is intended behavior, that's alright, but it's an unintuitive behavior. When you set a domain, you expect things to work. At the very least make it clear, in the UI, in blender, that you have to set origin to geometry on the domain when baking instead of making the user think he's doing something wrong, then ask around, then maybe dig in the documentation to find out why. Alternatively, you can just add a checkbox like "Set origin to geometry when baking" in the mesh baker menu. All it would have to do is run that function before doing the baking. Behavior remains the same and it's more user friendly with a minor automation.

blender-admin commented

2020-05-20 16:52:03 +02:00

This issue was referenced by b44101950d

This issue was referenced by b44101950d12d6d1f75507df03a902bf8387e074

Jacques Lucke commented

2020-05-20 16:53:04 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Jacques Lucke closed this issue

2020-05-20 16:53:04 +02:00

Jacques Lucke self-assigned this 2020-05-20 16:53:04 +02:00

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Wrong location of FLIP fluid mesh after editing domain mesh #73979