• Drag and drop the red fluid glass from below through the upper shelf collider and through the blue and green glasses without affecting the liquids at all - it should just pass through it.
  
• Rotate the red fluid glass so the red fluid pours out. Once the red fluid has left its glass it should be stopped by any other glass (i.e. fill those glasses and mix with any fluids inside) or the shelf.
  

• If I make the simulation 3D with very flat models, it would still look 2D in an orthographic camera and I could use the Z-axis to make a grabbed glass and its contents ignore any other collider. When the fluid leaves the grabbed glass trigger volume because it is poured I could adjust the Z-position of those now-outside-the-glass fluid particles back to the Z-position that everything non-grabbed is on.
  
• If there is a way to have multiple simulations and to transfer colliders/fluids between simulations, I could temporary make a grabbed glass and its fluid a separate "grabbed glass" simulation and return any fluid that leaves the grabbed glass to the "main" simulation.
  

(21-06-2024, 03:31 PM)Tobias Wrote: Hello,

I'm new to ObiFluid and I'm currently working on a 2D bartender game where you can grab glasses with fluid, move them around and pour the fluids into other glasses (or onto the shelves).

For example, I'd like this to work:

• Drag and drop the red fluid glass from below through the upper shelf collider and through the blue and green glasses without affecting the liquids at all - it should just pass through it.
  
• Rotate the red fluid glass so the red fluid pours out. Once the red fluid has left its glass it should be stopped by any other glass (i.e. fill those glasses and mix with any fluids inside) or the shelf.
  

So, in short, I'd need a *grabbed glass with liquid* ignore all non-grabbed-glass colliders/liquids, and *liquid that has left a grabbed glass* to normally interact with the world.

Liquids can mix, so I don't think I could do anything like "liquid from the red emitter behaves differently" - it might be glass mixed with red and blue liquid that is grabbed, while other glasses also already have red or blue liquid.

I see two ways this could happen:

• If I make the simulation 3D with very flat models, it would still look 2D in an orthographic camera and I could use the Z-axis to make a grabbed glass and its contents ignore any other collider. When the fluid leaves the grabbed glass trigger volume because it is poured I could adjust the Z-position of those now-outside-the-glass fluid particles back to the Z-position that everything non-grabbed is on.
  
• If there is a way to have multiple simulations and to transfer colliders/fluids between simulations, I could temporary make a grabbed glass and its fluid a separate "grabbed glass" simulation and return any fluid that leaves the grabbed glass to the "main" simulation.
  

Do those ways sound possible? Is there any other (maybe better?) way to achieve this?

(26-06-2024, 06:05 AM)Tobias Wrote: Oh, there are collision filters for particles. Does that mean I could also leave everything in one 2D simulation and make my scenario work by just changing the collision filters for inside-a-grabbed-glass fluid particles (and again when they leave the grabbed glass due to being poured out)? Or is collision between fluids not controlled by collision filters?

Quote:Please note that fluid particles do not collide with each other, only granulars (gravel, pebbles) do. Fluid particles interact with each other trough density constraints, so there will be no contacts between fluid particles reported by the solver. With fluids, you can use advection or diffusion instead to get information about a particle's neighborhood.

(26-06-2024, 08:01 AM)josemendez Wrote: You should instead move the emitter to a different solver (you will also need to re-emit active particles and set their positions afterwards)

(26-06-2024, 05:00 PM)Tobias Wrote: Can I also move particles between emitters? Since mixing fluids is the point of the game, the glass can contain fluids by multiple emitters, and other particles by those same emitters will be in other glasses.

(26-06-2024, 05:10 PM)josemendez Wrote: Hi,

No, as it generally doesn't make any sense: moving a particle to another emitter would suddenly change all its properties including rest density, mass, size, pressure, etc, potentially breaking the simulation.

Note you don't need to move particles between emitters in order to mix them: fluids from different emitters can interact with each other, and you can use diffusion to smoothly transfer properties between particles belonging to different emitters.

kind regards

1. Bottle A contains red liquid from the emitter 1. Bottle B contains blue liquid from emitter 2. Glass C and D are empty.
   
2. Into glass C and D I both pour 50% from bottle A and 50% from bottle B. Now both glasses contain mixed liquids from the same emitters.
   
3. I now pick up glass C. While I'm moving around glass C, I want it (and its fluid contents) to be able to pass through glass D (and its fluid contents) without any interaction.
   

(26-06-2024, 06:36 PM)Tobias Wrote: Yes, but in this case I want to be able to have diffusions from the same emitters ignore each other temporarily under certain circumstances. Take the following scenario:

1. Bottle A contains red liquid from the emitter 1. Bottle B contains blue liquid from emitter 2. Glass C and D are empty.
   
2. Into glass C and D I both pour 50% from bottle A and 50% from bottle B. Now both glasses contain mixed liquids from the same emitters.
   
3. I now pick up glass C. While I'm moving around glass C, I want it (and its fluid contents) to be able to pass through glass D (and its fluid contents) without any interaction.
   

I can't just move any emitter to a different solver here. Both glasses contain a bit of fluid by the same emitters.

Quote:In that case you will need to do this in 3D and use depth to prevent fluids poured on different containers from interacting with each other.

Quote:moving a particle to another emitter would suddenly change all its properties including rest density, mass, size, pressure, etc, potentially breaking the simulation.