Category: hou-effects

Archived post by trzanko

lil bit of triangle stretch and skin sliding + bend plasticity

was kind of all about finding the right balance of attach stiffness and slide

if you stiffen the slide and loosen the constraint you get bigger folds

and if both stiff you get really fine wrinkles, could be really cool to run on a face or hands

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20195512/06/19/skinSlide_v001.hip

Archived post by trzanko

there’s a pretty neat trick to getting noisey edges without the rbdmaterial fracture sop

the stuff they do in rbd material fracture to compute the intersection planes is pretty intense

so there’s this as an alternative

doesn’t pass every test

but with some love it can get pretty nice results

excited for the guiding stuff, rolling my own on a job rn and would be interested to see their approach ( it’s for sure better haha )

i imagine their guiding method point deforms a tet mesh to the anim geo, and then perhaps they extract a rigid anim xform off the derivatives of the rest / anim tet deformation, and activate pieces by the difs in the rest / anim xforms; shear, scale, rot difs, etc

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20195411/07/19/edgeFrac_trzanko_v001.hip

Archived post by Sasa Budimir

Little trick for those nasty gaps and weird sim behavior in vellum when using attach to geometry constraints. Say you have some vellum sim and want to attach few lines/hairs to it in the second sim (using the first one as collision). There is always a small gap between attached points, and after some time I figured it was due to collisions between those points that is forcing them apart, and causing some weird motion. Easy fix is to just disable collisions on those points that are going to be attached with: `i@disableexternal = 1;` Little GIF that hopefully illustrates things better (or not).

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20192910/24/19/disable_collision_vellum.gif

Archived post by Lorne

this is kind of a cool little thing, was working on some sims last night with very visible source volumes that I wasn’t happy with the look of, but also wasn’t happy with how little density was coming into my sim from them either…usually I’d probably try to rework the shapes and crank the density a bunch on the source, but ended up trying something that worked way better:
– go way lower with your source density than you’d normally think to, like 0.05 kind thing – gas wrangle — @density += @temperature * clamp(@density, 0, 1) * chf(“mult”);

now you’ve got a smoke density that’ll grow a bit more after it’s sourced, but in a really natural looking way that doesn’t show your source so badly and will be swirling and advecting while it continues to pump density

Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20193710/02/19/density_growth_v001.mp4
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20193710/02/19/broom_puff_fx_main_v008_720p.mp4