Particles in a conveyor

[JuhaHo]

Thanks everyone,

After spending about two months including weekends and holidays I'm still nowhere near the solution. The client is becoming a but frustrated with me. However, I still cannot control the particles properly. Instead they are exploding all over the place.

Is there any ides what to try next? Maybe I've been doing it in a wrong way from the beginning.

[JuhaHo]

Now I'm doing a little test with copilot. I'm asking steps on event to event, operator to operator basis. Let's see what we get now.

   

[JuhaHo]

At he moment I'm playing with the Rotation operator. How it should be configured if I want the particles to keep their orientation towards their traveling direction.

   

[d4rk3lf]

For travel direction, make sure your timing is set to continuous (so it updates every frame), and keep in mind that it takes Z axis as a forward, reference to orient particles.
This is why rotation have additional options to further rotate your particles (if you don't want them to be Z oriented).

[JuhaHo]

I still don't get this. I have now spent more than three months trying to get the particles correctly out of the conveyor. I don't know what I'm doing wrong. On the picture I have outlined the particles that are behaving correctly when leaving the conveyor. The particle system explodes when I send them to new event. On the moment particles reach the to, they become very unstable.

   

I made similar animation about 15 years ago with PFlow/Orbaz tools. Now they want modernized version of the animation. However I have a long way to go to get the level of the old animation.

I also attached screenshot of tyFlow. I underlined the operator that explodes the simulation. Are there any other ways to drop the particles of the conveyor?


   

[d4rk3lf]

The only operator I see in the second event that might force them to explode is Particle Physics.
What happens if you turn off Particle Physics in the second event?
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- I also see operators that doesn't make sense. Why do you need particle physics in first event (considering you are using object bind)?
You basically force them to repel out of each other (particle physics), and then you lock them to the surface right away (object bind)... this can also cause instability, because you apply 2 opposite stuff at the same time... oh yeah... and you have collision in there too.

- Also in the third event you have fluid force, multifracture, particle physics... I mean... this can work... but you need to be careful... you are basically forcing particles to be driven by fluid simulation, and then you force them to repel of each other, and on top of that you fracture them more... this can also lead to explosive behavior.
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Don't just throw operators in the flow, without knowing what they do exactly.
Why don't you make a version of very simplified scene? Like.. instead of using many particles, use 10-15...
I also created you 3DS Max file long time a go to help.
There is also conveyor belts scene in official sample files.
-
All in all, I really don't see what is causing you so much issues... try disabling particle physics everywhere, and see how it goes.
-----------------
As for Particle flow / Orbaz tools.. I've used them for years... and they are not even close to TyFlow in any segment... even first TyFlow Beta.
For example, I did this animation, long time a go, with one of the first TyFlow Beta's, and setup took me just few hours... with Particle Flow it would have took me, much much longer.
https://www.youtube.com/watch?v=OqH4C4xwccU

[JuhaHo]

Thanks,

I use particle Physics for Particle-Particle collisions. If I didn't have that Two things happens:
1. The particles are not piling up so the particles form a flat carpet
2. The will be tight particle concentrations, because the particles want to be in same place and don't know that's already crowded.

After the chute, there's liquid, where the particles eventually dissolve. I have multifracture operator to split particles gradually and size test operator to vanish small particles until there's only liquid there. I have liquid force to move particles along with liquid. The liquid is moving constantly.

[JuhaHo]

I removed the Particle physics from the second event. The particles don't explode as much, however there's stray particles in the first event. I have a speed limit, but it's not enough to control these unstable particles.

I think I reduce the speed limit even more.

Anyway, the looks awful without physics in it.

   

[JuhaHo]

Yet another failed attempt. I really don't know which direction to tweak this.

   

[JuhaHo]

What is this? I think something is not right here. Can Tyson explain this?

   

[JuhaHo]

One thing, I don't understand is Time test Event operator. How it should work? For me it affects the particles in first event too. How can I avoid that? I want to send particles to next event, not to previous one. I'm sure there's logical explanation for that.

It seems the particles are sent to third event directly from first event skipping the second event, where particles are falling through a chute. For me it would be logical, that time test affect only particles in second event, where the operator is. Is this possible.

So, I need an operator that tells when particles are ready to start breaking. It requires right time and place. Is this possible in tyFlow?

   

[JuhaHo]

Since I got so horrible looking results with tyFlow, after three months I decided to go back to square one. I think the problem start, when the particles enter to conveyor. You can see the particles are coming through the walls of the conveyor and there are way too few of them. Also the particles are penetrating each other, which look very bad on renderings.

Anyway, the simulation crashed at frame 2700, because it exhausted the resources. What would You recommend next?

   

   

[JuhaHo]

If I go back to beginning where I was about three months ago. Is it possible that the problems start from this point. What do I need to do to keep the particles inside the side walls?

   

   

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I could use collision radius of 250mm, but then the particles are hovering way above the conveyer. Is there a way that particles would respect both: the sidewall and the conveyor itself. Now it looks awful.

   

[JuhaHo]

Why are my particles hovering over the conveyor?

   

[JuhaHo]

Spending yet another sleepless night with this project. I started this all over again. What do I need to do, so particles would not penetrate the conveyor. However next week I need to pay VAT for this project, I never expect to be paid and after that there's this corporate taxes for this project. I'm in deep trouble if I can't get this right and that's what keeps me up all nights.

   

   

Edit: I changed Collision radius from Absolute to Shape. I see that the particles are overlapping less with the conveyor, but more with the side walls. Is there a way to tell tyFlow, where the particles actually are?

   

[JuhaHo]

For comparison, I opened an old Pflow scene, I made about a decade ago. The particles are not penetrating through floor nor each others. I wish tyFlow were this advanced someday.

As far as I recall, the Yost Group IPAS plug-in particle systems for 3D-Studio MS DOS in early 90's could handle this situation.

   

[JuhaHo]

I'm now Testing PhysX approach. I don't know if the set up is correct. However, I wonder, why the particles start moving very slowly, when they are climbing uphill. At this point the first particles should have gone up to the folding roll. Do I need another operator, or what?

   

[d4rk3lf]

You are not listening what I am saying.
What you did with Particle Flow can be done with TyFlow with several clicks, and 3-4 operators.

Here is what I wrote on the first page of your thread: 

Either that... Or... avoid using PhysX for this... just use Particle Physics (if radial particles collisions are enough), and just use regular collision operator.
Again.. version of setup like that is also in my file.

and... 

As for penetrating particles... for this kind of particles it might be better for you to use PhysX (but it will be slower to sim)
Particle Physics can only collide in spherical manner... also object bind might lock them before they repel of each other (it can look even PhysX particles).

So, again... read carefully 
Here is your options (solvers): 

1) PhysX Shape (particles will perfectly collide with each other no matter what shape they are). It's slowest method, but most accurate. 
Keep in mind that by default, a gravity is enabled (you don't need force), and ground collider is enabled. You can turn off and on these settings if you grab main Tyflow Icon, go to the modify panel, and switch these settings on and off. 
Also, you shouldn't use Collision with PhysX... you should use PhysX Collision operator (mesh is preferable if you have complex collision mesh) 

2) Particle Physics (particle will be colliding in only spherical manner... imagine like you draw a sphere on top of each particle, and these spheres will be used as collision. This is much faster then PhysX Shape, and is used if you have grain type of simulation.. or some balls type of objects... 
Very important - you can preview these collision spheres in Particle Physics, if you go inside opetions of that operator, and under display you can check "draw collision shapes", then you set up their radius to your liking, and voila... 
You use regular collision operator with Particle Physics 

3) No interparticle collisions. 
This is when you neither use PhysX or Particle Physics, and that way, the particles will only collide with collision operator, and just where their pivot point is (basically dots). 
-------------------------------

Now according to your needs, you use whatever solver you need... and sometimes, it's wise to turn off Physx in certain events, so you avoid long calculations. 
If your particles are fractured so much that they basically turn into dust, or small grains, there's no point of keeping them in PhysX solver, but you can add PhysX switch (deactivate) operator, and then just use Particle Physics, or not use any inter-particle collision at all. 

It's really hard to give you exact advice, because sometimes it seems like you have big particles that requires Physx.. sometimes you fracture them so much... then even use fluid solver and drive particles with... 
As I said previously... use 10-15 particles for testing... and see if they all go through events to your liking... you can easily bump their number after that, and it will save you of long calculations. 

Hope this helps.

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I'm now Testing PhysX approach. I don't know if the set up is correct. However, I wonder, why the particles start moving very slowly, when they are climbing uphill. At this point the first particles should have gone up to the folding roll. Do I need another operator, or what?

Nice! 
Is your belt animated or static? 

Try animating it... look at some tutorials on how to do tanks treads or conveytor belts. 
After you animate it, you might want to increase these 2 friction parameters, so they stuck on the belt.

[JuhaHo]

Thanks,

Yes the conveyor is animated (actually it's not belt, its's as they say a slat conveyor).

What comes to friction, when it's set to 0 particles follow better. That's why I had the bind operator with non PhysX flow.

I'm now trying to figure out how to make particles move with the conveyor. They follow the conveyor until it starts climbing uphill. Here's the point where the particles stop moving along with the conveyor.

Of course it might be, that I miss some thing, because I can't sleep while thinking this. Last time I had similar pressure, I got shingles to my left eye duo to too much pressure by the clients. It's a nasty disease, it destroyed sight of my left eye.

   

[d4rk3lf]

It works here.
I just used simple plane and animated it and slice it with box (Boolean)

PhysX Shape is everything by deafult.

Maybe you can do the same trick, and hide the plane

[JuhaHo]

Thanks,

I think I found something, but I don't know how to fix that. In my original system I had plane emitter with speed. You example had sphere emitter. So I replaced my planar emitter with sphere. I see, that the particles are not moving on the conveyor any more. However, after spending couple of hours investigating this, I couldn't find any difference.

   

[d4rk3lf]

Emitters shouldn't matter.
It's same if it's spherical or planar emitter....

if your particles doesn't move upwards, I'd investigate how that conveyor is animated.
In my simple example, plane works with no issues.

[JuhaHo]

Yes, I made sure, the conveyor is animated. To make sure, I replaced my simplified "belt" with the render geometry, but nothing changed.

Frame:
23 particle its conveyor
24 particle is aligned with conveyor
25 particle bounces a tiny bit
26 starts moving to opposite direction compared to conveyor.

The animation will have duration of 242 seconds. I have now spent more than three months, but I can't get right even the first second with tyFlow.

[d4rk3lf]

I don't know what is wrong.

If you can share the scene, I can take a look.

[JuhaHo]

I think I can't share my scene.

Anyway the particles only pile up on the conveyor. The conveyor travels under the particle, supporting the particle pile, but the particles are not moving on it. This is below the ground level, so I don't use Ground collision. In reality, the particles are poured with a wheel loader to the conveyor, but it's not necessary to show it here, just the conveyor transferring the particles. I just need to know if it's possible to create particles in a conveyor animation with tyFlow. It seems, that it's not possible.

I made the the original animation about 15 years ago with PFlow, and there it wasn't problem.

It would be great if Tyson would say a word about this.