Question Looking for a way to rotate particles around themselves based on a predefined position

Hi,

I use a Sample Bezier node to position particles along a curve when they spawn. Now I would like them to rotate along the y axis at that position.

Anyone have an idea? Maybe @VladVNeykov ?

Here's my initialize particle module:




Here's how it looks like, you can see cubes where my points are:


You guessed it, I'm reworking my tornado and I want the particles to rotate around a point on that bezier curve.

I'm kinda lost. I tried Rotate 3D but it doesnt respect the bezier curve.

Thanks

 

Thank you so much! You are a savior. Any idea how to give particles an upward velocity that still follows that curve? it just needs to feel like it's going up a bit

 

I tried using it in a set velocity node in the initialize context, but the particles don't exactly follow the curve. They actually offset themselves over time, so my tornado kinda doubles itself in waves

 

Thank you again so much! Great support as always.

I've been trying to plug this into my vfx graph which contains some more controls like particle size relative to the width of the tornado, some randomness, etc.

When I tried adding your "add value over lifetime" group and connect it to my system, it gave me really cool but weird results. Here's my graph if you wanna take a look, I feel like I'm missing something when simply replacing the output of the first modulo and plugging it into the new group before everywhere else.

 

Thanks, I tried your package and it confused me a lot as almost everything was moved to the output node and I use a lit output node as well.

It looks like not everything worked when I sent the vfx, so I made a package.

Here's the features I added myself:
- Particles scale up when the radius of the arc scales at that position
- Rotation will go slower if the radius is bigger and faster if the radius is smaller
- Particles are lit and are using a 4x4 sheet flipbook blend

The effect looks like this:

Notice how I can move my bezier points and it will follow but only the newer particles will spawn correctly, the old ones are not moved. Probably because they're not in the output node

Thanks again

 

So let's say I move my blocks to the output node, I solve the problem of moving the bezier points, it now works perfectly. However, something's suddently wrong with my particles, it looks like they're having a party with strobe lights

Edit: I also used Total Time (VFX) in the "rotate around the bezier curve" instead of delta time like you mentionned.

And then if I try to add the value to make them go up, this happens:

 

Here's my latest package with what I mentionned above (Bezier works real-time, but everything flashes weirdly, and I can't get upward movement to work) in case you want to compare the 2 rendering results.

 

Thanks again.

I now have upward movement working, but there's some things I'm not sure why they are happening.

Your note here, you're dividing 0.05 by the lerp's value, and then doing nothing, so I'm unsure why it's there.

Now here in the following screenshot, my add-on to make particles rotate slower when the radius is larger is gone:


Strangely, if I do what I had done (next screenshot), it does make it faster on small radius and slower on bigger radius, but suddently it rotates the other way around and I can't figure out why. It also slows it down way too much on the larger parts of the tornado:


Other than that, what really bothers me is why your screenshot doesn't show the "flashing" effect while mine still does.

I know I'm asking a lot and I can't thank you enough! I really wanna understand what's going on there!

 

Thanks, most of my issues are now fixed. Except that flashing effect that you clearly don't get on your side.
Here's an example, I tried with a lot less particles at the beginning to show you how it's not rotating that fast. Then I add more particles and you'll clearly see my problem:

 

Here's another example to illustrate my problem:

 

Same setting with 30 particles instead of 300:

 

One last video: Is this a bug? I turn on the coloring, and it slows down rotation? The VFX Graph is not even attached to the Visual Effect.

 

Alright so it's really weird actually. Just noticed the rotation actually speeds up over time. Something has to be wrong on my side.

I place my VFX prefab on the scene, speed is fine. I wait for about a minute and it's going about 2 times faster.

The rendering bug where particles are drastically changing their lighting keeps happening no matter what.

I tried to put my entire graph in a screenshot so it's visible without downloading a package. There has to be something I messed up, but I can't figure out why

 

Flickering:
My flipbook seems correct, here's the texture:


The Set Tex Index over Life curve goes from 0 to 1 in X and 30 to 0 in Y (I wanted the animation to go in reverse).

Now, when I disable shadow casting, the flickering still happens, but there is indeed no shadows. Weird thing though, when turning shadow casting back to ON, shadows are not working. I have to do CTRL + Z two times for them to be visible again:

When converting the output to unlit, it still flickers:

Now if I play with sorting, I don't see the flickering anymore when turning sorting OFF, but you can see particles that should be hidden by others:

Now when reducing capacity, it doesn't change anything with the flickering (and of course down to a point, you can't see all the tornado anymore)

I also tried disabling blocks but aside from either not rotating or not being at the correct position, no change in flickering.

In case this helps, here's how it looks like when getting really close to it. It's as if each particle was trying to pop in front of each other:

Thanks again!

 

Thanks, I'm very glad I could help find this issue! I sincerely hope it can be hotfixed in 2021 as it's the mostly supported LTS right now and we're actually almost done with upgrading our project from 2019 to 2021, which wasn't fun times!

Thanks for your time and enjoy your time off if that's what's keeping you out of the office for the week

 

Hi Vlad,

Just wanted to ask, should I report this issue somewhere? Or did you mention it to the team? Thanks, hope all is well

 

THANK YOU SO MUCH! Very lucky to have you here to help That fixed it.

 

Now how would I, using this setup, keep some of my particles and only use those aside on a block while the others are still doing that ?

 

My bad.

I would like to "reserve" some particles for a dust cloud on the ground, so they don't get placed in the tornado. And then I would like these particles to be affected by a vector field, for example.

However, I'm not sure where I should split the particles to keep some for my dust cloud, and then I also don't quite understand how you can place a block like vector field force, and only have some particles be affected by that block, not every one of them.

 

Thank you I will work with that. Again, 10/10 incredible support <3

 

Hi again @VladVNeykov

I made a dust cloud at ground level, and it has its own bezier curve, pretty much the same system as the main tornado.

I am looking for a way to create some sort of turbulence or distortion in it now to simulate this:

It's pretty much as if the dust cloud was made of multiple vortex dancing around each other. Doesn't have to be that precise, but that's kind of the feeling I'm looking for. Ideally, I'd have a multiplier from 0 to 1 that would enable or disable this "turbulence".

Any idea?

 

In the end, I'd like to have a float/slider from 0 to 1 that will affect the dust cloud only. at 1, the dust cloud would be made of multiple small vortex rotating around the main axis appearing and disappearing randomly with noise, and at 0, it would be a regular thick dust cloud like it already is. I thought maybe with some noise/tubulence (no idea how though) I could get an effect that makes it look like there's small vortex without actually making small vortex, but whatever makes it look close to my reference would be awesome.

No worries for any delay, I very much appreciate the help you gave me. Enjoy your time off!