Author: admin

Archived post by ajk48n

For future reference, here’s a tridiagonal solver in vex (very much not optimised, but it’s based on some Mathematica code) @jake rice 😮
“` #include #include
function complex cdiv(complex a, b) { complex conjB = conj(b); complex num = cmult(a, conjB); complex den = cmult(b, conjB); complex ans = cmult(num, CMPLX(1.0/den.real, 0)); return ans; }
function complex[] TDMAsolver(complex a[], b[], c[], d[]) { int nf = len(d); // number of equations complex p[]; complex q[]; for (int i=0;i=0; i–) { q[i] = csub(q[i], cmult(p[i], q[i+1])); } return q; } “`

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

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

Archived post by JeffLMnT

“` How to deal with Iterations: Substeps – More expensive, but gives a better solve – especially for higher stiffness values Constraint Iterations – Increase for higher stiffness value to control excessive deformations – great for cheaper solver at high resolutions Smoothing Iterations –  smoothing ops, to smooth out errors of excessive deformations, or constraint errors Collision Iterations – Uses the Detangle sop – lower frequency iterations – complicated and time consuming – increase when collisions are fighting against constraints or other collisions However, its probably better to increase substeps and decrease constraint iterations for a more accurate solve – and to reduce load on the constraints – but is more expensive “`