dealing with open geometry

[evanrudefx]

Hello,

For some recent freelance work I have received geometry from modeling which will interact as a collider for some smoke simulations. The geometry (as often is the case it seems) isn't properly closed up in areas that are not rendered. I assume modeling thinks if something isn't being rendered the topology isn't important. It's difficult to set up sdf collisions for pyro because everything is open. Any advice for how to deal with this? Is there some alternative to pyro collisions that do not require sdf's, or do I just need to close everything up. I feel like I would spend more time fixing the geometry then doing the simulation : )

Thanks

[Noobini]

polycap (or fill) + pray hard it works ?

[evanrudefx]

3 minutes ago, Noobini said:

polycap (or fill) + pray hard it works ?

haha, unfortunately that doesn't work in this case

[DaJuice]

Have you tried the Convex Decomposition SOP? It can close up holes, at the cost of sacrificing some of the original shape if you push too hard on Max Concavity.

[evanrudefx]

15 minutes ago, DaJuice said:

Have you tried the Convex Decomposition SOP? It can close up holes, at the cost of sacrificing some of the original shape if you push too hard on Max Concavity.

1000 iq move, lol. I will give that a shot

[ikoon]

This might help, in some cases. Divide SOP, Remove Shared Edges, and then Fuse with original.

At least Divide SOP might expose to you, where the holes are, and take care of them separately?

[evanrudefx]

oh nice, I will try that

[paranoidx]

SDF for open shape in case you need

https://www.tokeru.com/cgwiki/index.php?title=HoudiniVolumes#SDF_from_open_shapes

 

[evanrudefx]

Unfortunately that doesn't work. The collision is way too thin. I did something similar. I use a vdb from polygons then reshape sdf on dilate to make it thicker

[paranoidx]

Did you create vdb topology ? Its purpose to create the vdb along only on surface so technical you have an object similar image above. Is that what you want ?

[Atom]

Try polyfill with a fill mode of Single Polygon. Also, I've use polyextrude to add thickness to walls of open game meshes. Extrude inward, not outward to preserve shape.

[Librarian]

@ejr32123 or maybe you can build you Own systems and somehow go a  Round, just idea   .
 

SdfF.hiplc

[evanrudefx]

Thanks all for the answers

[paranoidx]

Just curious, can you post your issue screenshot here? I would want to see that mesh. If possible.

[evanrudefx]

sorry, I cannot. But using the different methods listed above pretty much have me covered