# swirly lines catching object moving

## Recommended Posts

Hey magicians,

I'm trying to figure out the best approach to make something like this, idea is having some lines that came from back and try to catch the airplane flowing around it with a nice flowy motion:

So far I tried having some pop emitter at the back, and using attractor / collider to get the particles flow in that direction, with no luck.

I also did some manual curves to use with curveforce but i'm trying to make it more procedural, avoiding manual curves.

I also played a bit with find shortest path, wich is the closest, but wanted to make something in pops to get more flowy movement.

Here are some frames of what I get with shortest path:

Any thoughts or ideas will be super helpful, feeling stuck here.

Thanks!

##### Share on other sites

try to convert airplane to VDB and use Curl Noise with VDB input in the POP VOP

• 1

##### Share on other sites

Ola !

You have more experience in production so, just play with trigonometry, than find points and make trails. I think it helps ..

particlesOdfr.hipnc

• 1

##### Share on other sites

10
On 1/29/2020 at 1:19 AM, caskal said:

Hey magicians,

I'm trying to figure out the best approach to make something like this, idea is having some lines that came from back and try to catch the airplane flowing around it with a nice flowy motion:

So far I tried having some pop emitter at the back, and using attractor / collider to get the particles flow in that direction, with no luck.

I also did some manual curves to use with curveforce but i'm trying to make it more procedural, avoiding manual curves.

I also played a bit with find shortest path, wich is the closest, but wanted to make something in pops to get more flowy movement.

Here are some frames of what I get with shortest path:

Any thoughts or ideas will be super helpful, feeling stuck here.

Thanks!

Can you not combine shortest path an Pop, feed your pop with the the first ones and play with that? Not my speciality, just a thought...

##### Share on other sites

Sometimes we getting a little blind by the all proceural approach. there is nothing wrong  for art control and speed reason, just a bunch on draw curves as input for your simulation

##### Share on other sites

Hey guys,

Thanks for the tips!

@Librarian what version of houdini are you using? im on 17.5 and the pop network reads like a merge node (so cant see the anim), any thoughts?

@vinyvince indeed! that was the plan B if I can get there, so draving some curves will be the best option for art directing, thanks!

Cheers

16.5

• 1

##### Share on other sites

Here is a quick hack with Librarian's plane dropped into Farmfield's wind tunnel.

Edited by Atom
• 3
• 1

##### Share on other sites

Another attempt. Once a particle comes in contact with the collision surface, it uses a volume sample to fetch the direction to push @P.

```float vs = volumesample(1,0,@P);
if (vs<0){
// Yes we have collided.
@P+=vg*0.01;
i@group_collided = 1;

}```

Edited by Atom
• 1

##### Share on other sites

And there was that swirly head tutorial, a few years back...

ap_swirl_lines_around_airplane_013020.hiplc

• 1

##### Share on other sites

Hey @Librarian no worries, thanks for the help!

@Atom these look great! will analize your hips now, thanks a lot for all the info!

Cheers

##### Share on other sites

I have the tool you need, my problem is how and where to share this kinds of things. Not that eager to just drop the hda in a place where i have no controll over it.

##### Share on other sites

@ThomasPara jooooj just share your candy

##### Share on other sites
22 minutes ago, ThomasPara said:

Not that eager to just drop the hda in a place where i have no controll over it.

Control is an illusion.

Unless of course you created this tool for a client. Then, technically, it's not yours.

##### Share on other sites

Its more in how people use the tool, since its werry complex and maybe not that intuitive i want the ability to update the tool. I also want to present it in a way that people can see how its used. When it comes to the code, i offcourse loose all control, unless its a blackbox, but thats kinda unfair.

But i have made an example using pops that can be further built on, and that have the same core principals.

popcurves_01.hiplc

• 5

##### Share on other sites

Thanx for your time and knowledge.

• 1

##### Share on other sites

My knowledge comes from other people sharing their knowledge. And odforce is a place where i have gained alot of knowledge, and i hope people will continue to share their stuff so i can learn more.

• 1

##### Share on other sites

Exactly @ThomasPara

##### Share on other sites

Still playing around with this. A volume sample multiplied by volume gradient push points along the surface, assisted by wind. I'm not sure how to detect the occasional "escaping" particle and terminate, however.

ap_pop_conform_to_surface_with_wind_020120.hiplc

##### Share on other sites

Even more experiments. this file contains three different approaches.

ap_tut_lines_over_surface.hiplc

• 2
• 1

## Create an account

Register a new account

×
• Donations