https://youtu.be/g1wT1LW7hfs Vellum SOP.hiplc

Geometry

Configure Parameters

Geometry

	low
Mass	0 - mass inactivete		Can set from param or calculate
Thickness			( `edge len scale`- multi for thick) Can set from param or calculate

check thickness. should be smaller than distas between points

Drag

Slow down motion

Stretch

For cloths, curves or constraints (like attach)

	low	high
Stiffness	1 - stretchy (spandex)	1e +10 rigid (leather)	How stretchy material is (default infinite)
Rest Lenght Scale	0 - to snap all points in one	1.1 - 10% larger after sim	Rest of edges (default 1)
Compression Stiffness	10 - paper remain curled	1000 - rubber (hi resistance )	How much can compress material (lower distance between points)
Stiffnes Dropoff		Stop bounce	On distance (m) or angle
Damping Ratio			Lit more energy from sim if too lively (dont change) too much destory
Plsticity			Will return to rest pos.

wrinkliness (with low res sim lower param help to remove jagginess) / (if compress how likley it stay compressed) more is more likely stay (decrease more smooth look and dont enforce wrinkles)
f@restlength = f@restlengthorig + fit(f@mask,1,2); - restlength by param.
i@group_pin = @mask < chf("mask"); and add to ‘constraints stream (op2)’ by copy attribute > promote point to prim

Bend

	low	high
Stiffnes	0.01 - soft and bandy (silk)	1000000 - more rigid (plastic)))	How much resistant to unroll or bend
Rest Lenght Scale
Plsticity	will return to rest bend		/ treshold - below toehold will return to shape / rate - how fast become plastic / hardening while deform incresse
Treshold	enter new config easy and quick
Rate			make harden over time of banding
Hardening			make harden over time of banding

Constraints

Constraints are geometry attributes. Add in sop and edit it in velum Constrains Properties inside vellum solver to modify constr dynamicly

UI

Constrain Browser - window ! to chceck constraints

Types

Base

	Effect		When to use
Distance	Stretch	Keep distance Along Edges by Stiffness and Damping	basic
Bend	Rotation	Keep angle Across Trix	basic
Slide	Slide	H18
String	Distance + Angle	Cheaper than hairs
Hair	StretchShear + BendTwist	Use polyline or L-sys as input (its like distance bend and twist)
Cloth	Distance + Bend
Pressure		Compresable Volume (enforce volume depending on stiffness) (fstr than tetra)	Air
Tetra		Uncompresable Volume Tetrahedral fwm (requiure tetrah geo: solid conf SOP)	Liquids
Struts	Stretch Body	Conect opose sides. Good for stftb. that does not stiff tu much

Hard

Hard - Geometry point attributes
Direct update
Create / remove by setting point attribute

[Direct update]	Hard	Create / remove by setting point attribute	-
PinHard	Geometry point attributes	Set type: permament/stopped. `stopped`, `pintoanimation`	Pin to Target position
Weld	Geometry point attributes	Threat pts as one point and will look like 1 object Can break at stress level. (add bend across weld for smooth normal) Autobreakable (pre-tearing) `weld`, use pointid or groups !	Same @P (fuse), Fractured cloth

Soft

Soft -
Solvable
Create / remove by vellumconstraintproperty DOP node.
[plasticity / autobreakable]

[Solvable]	Soft	Create / remove by `vellumconstraintproperty` DOP node.	[plasticity / autobreakable]
PinSoft	Constraint primitive	Pin to Target position (remove manualy constr) / stiffness(magnes)	Magness, Pin to own anim to get detail in existing movement
Stich	Constraint primitive	Soft or Stich Weld. Points with in 2 groups that are far - keeping them apart. Can stitch to poligon instead point. SLIDE (remove manualy constr) plasticity. Can have spaces between points	Additional cloth pieces, keep distance

Name	Effect		When to use
Glue	Constraint primitive	Glue source to target distance treshold (check: nr constr per pt)(remove manualy constr) plasticity	Anim, 2 pieces
Attach		Stick to closest point on geometry & keep distance	Anim objects

Connect cloth to body = cloth + attach fix attach from nearest with interactive tool !! https://youtu.be/5s8I2fs8kMs?t=2081

Pin To Animation

submenu Wystepuje w curves lub pin to target

Permament Hard - Is storet as geo point attrib - not solving constr, update pos directly. mass = 0 (cannot be move by constsr)
Stop Hard - mass not changed but i@stopped = 1 prevent to inf;luence from constraints(same in pop)
Soft - constr peimitives (pin stitch glue) (inheret Strech Stif Parameters) can have varying stiff and breaking threshold
Orient Pin - for hairs
Match to Animation - animate with object i@pintoanimation = 1

Breaking

Weld have stress threshold Different types by: Stress or Ratio (sensitive, low values) normalize stress on solver - to normalizes for sub steps change

Collision

Surfeca colider You dont need VDB
You can ad per point friction attribute

Solver (DOP Forces)

OBJECT
CONSTRAINT
COLLISION

[Velum Constraint Properties] DOP

Change constraints properties (can animate here )

use groop to affect only one

[Velum Constrains] DOP

Set constraints here (change from 1’st to each frame creation)

Remove Pin Constraint

Unpin for soft constraints

(create output group in vellum constraint and use it in [Remove Pin Constraint] )
and check box REMOVE > 1
set time/frames

(WHEN u have animation, animate after constraints and before solver )

[Vellum Rest Blend] DOP

Blend 2 meshes to change rest position
There are two nodes SOP one and DOP one !!!!

Rest Blend SOP

Rest Blend DOP

https://youtu.be/_wFjD0xkM-E

[Pop Force] DOP

[Geometry Wrangle] DOP

Unpin for hard pin (Type: Stopped):

if (@Frame > 10)
{
  i@stopped = 0;
  i@pintoanimaion = 0;
}

Unweld

if (@Frame > 10)
{
  i@weld = -1;
}

Initially set Stress Type to None(0) (never break)

if (@Frame > 10)
{
  s@breaktype = "stretchstress";
}

Inputs (link to group node with group animation) and check if is in group:

if(inpointgroup(0,"unweld",@ptnum))
 i@weld = -1;

Setups

Set Target

Avoid time dependences - set when pining top not fetch animation to solver

Grain

[Vellum Configure Grain]
- Increase substeps 5+ @breaktreshold / @isgrain = 1 / @mass / @pscale / @v -

can set up to fluid !!

attraction weight - clumpy sand
repulsion wetight - used only When U want prevent grain+fluid to mix togheter (make softwr grain collision so not make sense for only grains)
phase - particle is velum fluid (if non 0). Same phase = same fluid.

========When solving viscosity and surface tention -

Rigid Grains

by shape matching

configure grain pieces
after sim: vellum xformm pieces -

Water Grains

Balloon

[Vellum Configure Baloon] = cloth Constraint + Pressure Constraint
anim stretch on pressure constraint
change volume setup: - rest length scale
Stretch Stiffness on Cloth and pressure. low - jellow , high stiff ,
Bend Stiffness - Cloth more bandy soft bodies,
Damping ratio - cloth stretch section

Expose output group in pressure @pstretch - @VellumsconstraintProperty inside solver forces cluster points - to glue constrain

Soft Body

[Vellum Configure Soft Body] = cloth + struts

Hair / Grass

!!!!!!!!

plasticity

Guided Animation

Use: Vellum Rest Blend

Tertahedral

use model: scale invariant ARAP ! new 19.5 (used in muscles)

there are grain collision options ! and open CL !

Post Process

[Vellum Post Process] SOP

Spply Welds - Weld geometry that have cuts and in theory should stick together
Visualize - !

[Detangle] SOP

run in for loop with feedback.

rest position as previous position
pscale

Drape

[Vellum Solver drape] SOP

To create drape from patches.
welding frame - where it start to fuse (maby work on frame 1 ?)
forces - increase velocity damping and air drag if cloth move to much

Drape solver help resolve cloths

Weld Points - create constraint, glue drapes by points. (breaking treshold)
planar patch from curve - from curves
planar patch - only simple shapes
planar pleat - make patterns

Mirroring cloth:

*_L*
*_R*

Name_RB - Right Back
Name_RF - Right Front
Name_LB - Left Back
Name_LF - Left Front

https://www.sidefx.com/tutorials/vellum-nodes/ - quick tuts https://youtu.be/NwabG-znu9Y?t=5745 - H 17 advanced wath end https://www.youtube.com/watch?v=zPQZ8KJTjzo - H 18 https://www.youtube.com/watch?v=iHtdex9kM-A - grab constr https://youtu.be/qAraO2E-v84 - megaplex part 1 (part 2 on gum) https://www.youtube.com/watch?v=8ge2W7KKwf8&t=163s - entagma stitches https://youtu.be/rQw2UZGWP-0 - rozwijanie płachty

https://www.youtube.com/watch?v=km2uXhfvWvk https://www.sidefx.com/tutorials/vellum-nodes/

H 19.5

Spatial Sort Interval. - Sot grain fluid particles in memory. It sould change particle count !!!!! (help with speed of grain fludi sim )

Geometry

Geometry

Drag

Stretch

Bend

Constraints

UI

Types

Base

Hard

Soft

Pin To Animation

Breaking

Collision

Solver (DOP Forces)

[Velum Constraint Properties] DOP

[Velum Constrains] DOP

Remove Pin Constraint

[Vellum Rest Blend] DOP

Rest Blend SOP

Rest Blend DOP

[Pop Force] DOP

[Geometry Wrangle] DOP

Setups

Set Target

Grain

phase - particle is velum fluid (if non 0). Same phase = same fluid.

Rigid Grains

Water Grains

Balloon

Soft Body

Hair / Grass

Guided Animation

Tertahedral

Post Process

[Vellum Post Process] SOP

[Detangle] SOP

Drape

[Vellum Solver drape] SOP

Mirroring cloth:

H 19.5

`phase` - particle is velum fluid (if non 0). Same phase = same fluid.