Falling Pixel Sort Effect

[jonjonmakemake]

Hello, 

 

I've been learning Houdini for a couple of weeks now and I'm trying to learn about particles more at the moment. I'm currently trying to create a grid of falling particles that look like a pixel sorting effect. (please see attached images and video link). My thought process has been that I need to create a grid to emit the particles and then attached trials that have a colour gradient to the trials with a falloff. I want the particle trails die out at different times and for the trials them selves to slowly fade away much like the trail of a shooting star or a light trail (hopefully the below examples clarify what I'm trying to say). I've been trying to figure this out and I've looked around the forum but can't find an example.

So far all I can get is my particles to fall the way I want with trails that have the colour gradient connected but that's all. Can anyone suggest/show me a way to create the look i'm after? I realise this might be a really rookie thing to do but from my own research I'm currently lost and need some hel

Thanks in Advance! 

Current Scene File:  Particles_Field_04.hip

Examples:

https://www.shutterstock.com/video/clip-1008242815-particles-glitter-rain-awards-abstract-background-loop

[schwungsau]

a lots of ways.... simple and fast way
at pointwrangle after the add note ithe code 
 

 

int prim_points[];
float umap;
addattrib(0, "point", "umap", 0.0);
prim_points = primpoints(0, @primnum);

for ( int i = 0; i < len(prim_points); i++ ){
    
    umap = float(i) / (len(prim_points) - 1);
    setattrib(0, "point", "curveu", prim_points[i], 0, umap, "set");
}

 then you can add a "color" node  -->  set it ramp from attribute with curveu as attr.  

[jonjonmakemake]

12 hours ago, schwungsau said:

a lots of ways.... simple and fast way
at pointwrangle after the add note ithe code 
 

 

int prim_points[];
float umap;
addattrib(0, "point", "umap", 0.0);
prim_points = primpoints(0, @primnum);

for ( int i = 0; i < len(prim_points); i++ ){
    
    umap = float(i) / (len(prim_points) - 1);
    setattrib(0, "point", "curveu", prim_points[i], 0, umap, "set");
}

 then you can add a "color" node  -->  set it ramp from attribute with curveu as attr.  

Thanks  Schwungsau I'll give it a crack when i get a break at work! 

[mestela]

Or some mild abuse of scatter, attribfrommap, attribnoise:

drippy_pixels.hip

[mestela]

Ah, added an alpha fade to the lines:

drippy_pixels_v2.hip

[jonjonmakemake]

Nice one Mestela i'll at look at this verison too! 

[kvaletet]

Oooh, fancy!