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Omitsu

Help with "nearbyPts" -- Trail/Curves generated from Alembic volumetric capture mesh

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Posted (edited)

 

Trails_noise.gif.13ac81d772168fb25aeba92412a1c706.gif

Hi,

I'm trying to achieve the effect of trail curves generated from a mesh-like the example above. (credits to matt from CgWiki)

 

select_points.gif.3b5389818894a3cbf0ebf47827eeca5a.gif

In my case, the mesh is an alembic mesh from a volumetric scan (above) - thus the topology is a mess and points move around or change ID every frame due to the scanning process. 

I've been trying different ways to connect the points that are emitted from the mesh through a popnet, however instead of getting a continuous curve, I get messy shapes and triangle forms. 

I've been using the attributeWrange with this VEX by acey195 on OCDFORCCE:

Quote

 

int nearbyPts[], pt, connectingPrim;
nearbyPts = nearpoints(0, v@P, chf("range"));

foreach(pt; nearbyPts)
{
        if(pt <= @ptnum)
        continue;
    
    connectingPrim = addprim(0, "polyline");
    addvertex(0, connectingPrim, @ptnum);
    addvertex(0, connectingPrim, pt);
}

 

 

This is how it looks with the wrangle: 

5eb88a33d90e9_Screenshot2020-05-11at00_56_12.thumb.PNG.9ace7a603dac301f2a8a66c1f7511cc2.PNG

 

And this is the particles:

5eb88a36bcd44_Screenshot2020-05-11at00_55_54.thumb.PNG.a98bdf4d5421a3a4c0f362f5280bd6e1.PNG

 

 

I very much appreciate someone guiding me through this to be able to get continuous trail curves out of this particular deforming shape: like the example with the sphere.

I guess that means creating arguments to not repeat using the same point more than once with the price of missing some odd/far points.

 

I'm new to Houdini btw :)

Thanks a lot!

 

 

 

 

Edited by Omitsu

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