Apex Cloth

An Apex Cloth Behavior (beApexCLoth) lets you simulate any Nvidia Apex cloth asset that was configured on the Character File. The Apex Cloth Asset can be generated with the Nvidia Maya DCC plug-in for physX 3.4 which is available on the Autodesk App Store

Creation

Behavior Editor / Behavior Library:
Golaem Menu: Crowd Behaviors / Behaviors / CrowdBeApexCloth Node
MEL command: glmCrowdBeApexClothCmd;

Configuration

An Apex Cloth Behavior defines the following specific attributes. For common attributes see Behavior Common Attributes.

There is full tutorial explaining the use of Apex Cloth here.

Cloth Attributes

Cloth Meshes	List of meshes asset to simulate with apex cloth. Several mesh asset can be specified by separating them with a comma (,). All the mesh assets must be listed as Meshes in the Geometry Tab of the relative Character File, and should have a Cloth Asset File correctly configured. The button on the right end is a helper with a list of all mesh assets present in currently loaded entity type. Use it to easier the configuration.
Scale	This attribute allows a choice of three modes : Random: Randomly set the scale value between the specified "Scale Min" and "Scale Max" bounds (this attribute is influenced by the random seed of the Crowd Manager) Per-Particle Attribute: Use the "Additional Cloth Scale Attr" attribute to get the name of the float per-particle field of the relative particle system. Golaem Attribute: allows setting the Scale value from the Golaem attribute set in "Additional Cloth Scale Attr".
Scale Cloth Pinned Vertices	Set to true if the skinned mesh on which the cloth is pinned is scaled accordingly
Gravity Scale	Gravity scale to use for the apex file
In Rigid Bodies	List of Crowd Rigid Bodies to use as colliders for the cloth. Limits: box primitives have to be considered as a 6 faces convex hull a maximum of 32 faces per convex hull can be used You can use the Vertex Limit configuration in the Crowd Rigid Body to try to lower the number of faces of the convex hulls.
Freeze Cloth On Stop	If checked, the cloth will keep the shape it has when the stop trigger is set true. To go back to the skinned version of the cloth, it will be needed to start again a cloth behavior and stop it without this option checked.
Frozen Cloth Bone	When the Freeze Cloth On Stop option is checked, this lets you freeze the cloth relative to the given bone rather than in world space

Note that meshes can be filtered by the asset repartition on the Entities Rendering Types. In such a case, the clothes will only be simulated on the entities that get the cloth objects.

Every mesh asset named in the "Clothing asset" list must exists in the Character File (.gcha).

Material Override Attribute

The following parameters override the value stored within the loaded .apx file

They are they same as the NVidia PhysX DCC plug-in ones. You can find a complete documentation about this plugin on the packages from the NVidia website.


Enable Material Override	Enable to override parameters from the apex file
Gravity Scale	Multiplier of gravity for this cloth asset
Friction	Between 0 (no friction) and 1 (rough and sticky) when the cloth rubs against itself or a rigid body
Bending Resistance	Between 0 (bends freely with small folds) and 1 (stiffer with larger round folds)
Shear Resistance	Between 0 (weak) and 1 (stiff)
Stretch Limit	How much cloth is allowed to over stretch from its natural length
Relax	Increasing this value results on a loosed, relaxed cloth
Damping	Dampen the cloth relative to its local movement
Drag	Dampen the cloth relative to global movement (root translation). Has no effect when set higher than Damping
Inertia Blend	Allows to blend between local space simulation and global movement. 0 being pure local space and 1 full global movement
Fiber Compression	Set the fiber compression by a percentage between 0 and 1
Fiber Expansion	Set the fiber expansion by a percentage between 0 and 1
Fiber Resistance	How are the fiber tries to get back to natural length
Motion Adaptation	Scales the mass of simulated particules to ehance simulation and prevent simulation problems with aggressive motions
Solver Frequency	Frequency at which cloth solving is done. Should be set as high as possible, but has an impact on performance. Advice is to start with 250 and increment if needed
Solver Iteration	Solver iterations are determined by dividing the Solver Frequency by your framerate (fps). E.g. if your framerate is 50 and your Solver Frequency is 250, then you are at 5 iterations

Starting / StoppingAttributes

Wind Attributes


Wind Adaption	The rate of adaption. The higher this value, the faster the cloth reaches the wind velocity. Set to 0 to turn off wind
Wind Velocity	The target velocity each vertex tries to achieve. This attribute can be animated / keyframed.
Wind Velocity Noise	Per entity noise added to the base Wind Velocity. Noise is computed randomly for each entity (within -noise and + noise on each axis), and remain the same for the whole duration of the simulation.

Starting / StoppingAttributes


Starting Duration	The duration that it take for the cloth to switch from fully skinned to fully simulated
Stopping Duration	The duration that it take for the cloth to switch from fully simulated to fully skinned