Category: hou-effects

Archived post by JeffLMnT

To quote @TOADSTORM you can punch tiny holes in the velocity field along the pressure front in order to break up big mushrooms. in a SOP solver connected to vel or sourcing input (set data name to “vel”), import the “pressure” field. use a volume wrangle to fit 0-0.1 to 0-1 (bind all volumes to density, f@density = fit(@density,0,0.1,0,1); ) then scatter points inside the density field, generate by density, scale ~7, max points maybe a million. fuse points by distance but keep unused points (not sure why this is done?) distance ~0.3 maybe. then in a volume vop/wrangle working on the vel field, open up a point cloud looking at these points. default radius ~0.25. get pcnumfound, if points are found, multiply vel by about 0.3, otherwise leave it alone. i think the basic gist is that you import the pressure field and then bind it temporarily to density, then ramp it to generate almost a band / isosurface so you isolate the main pressure front, then scatter points in it and use those points to “punch holes” in the velocity field. the easy way out is to just collide with scattered points but this A.) avoids collisions and B.) only applies at the pressure front so it might get cleaner and faster results

Archived post by trzanko

No, Initial state is the skin and tets at rest with the skin having the attrib pintoanimation set to 1. You don’t need a rest shape. Then target deformation is the deformed skin and the tets wherever, target strength parm can be 0 it doesn’t matter because of pintoanimation. You get the deformed skin of a tet mesh by setting the P to frame 1 and then piping the anim into an attrib, then after the solid embedd you set P of the skin to the attrib and there’s your target skin with matching topo. Here’s a file I had for debugging the workflow. Let me know if you have any questions.

you could honestly just change the inputs of this file and pipe the output into a wrinkle sim

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/createAnimTetMesh.hip

Archived post by TOADSTORM

yo @Fogelstrom not to toot my own horn but there’s a little section at the end of this blog post that goes into a similar kind of technique… you can generate “ribbons” of geometry or really any kind of surface and use it to drive volume shaders for nice sharp edges. it also means you don’t have to rely on pyro when things need to be more directable and less dependent on fluid dynamics.

www.toadstorm.com/blog/?p=465