Cloth Merged Mesh Deform

Overview

The Merged Mesh Deform Cloth is an improved version of the old standard cloth, where you have to use the cloth entity. It can be attached to any .cgf within your max file. You can use it on brushes as well as on vegetation objects. It gets affected by the global wind settings and breeze settings in the editor.

It is also optimized for PS3 and doesn't consume as much performance as the cloth entity. You can currently use up to 10 nodes to make it more SPU friendly. The SPU will calculate the nodes simultaneously in multiple threads. Splitting up your cloth nodes as much as possible will be more effective. The cloth nodes get merged into larger single objects in real-time. Every material ID get it's own merged object.

Currently you can't move the cloth along a Trackview or link the cloth to other objects in the editor. It can't change its position in real-time in-game. In this case, you have to use the cloth entity.

Setup in 3dsMax

Your cloth nodes need a main object where they're linked to. Currently it has to be a mesh and dummies/helpers are not supported yet. The main object is defining the name for your exported object. The cloth nodes have to be named "bendable", "bendable00", "bendable01", etc. You can fix single vertices in your cloth nodes by coloring them black in the vertex color channel (green channel, if the other channels are used for something else). Grey vertices get affected by the stiffness and white vertices are deformable without any stiffness. You can edit the cloth's behavior by changing the values in the user defined properties of the respective cloth node. You can use different properties, if you have multiple nodes to add more variety.

Setup in Maya

The main difference to the setup compared to 3ds Max is that each node needs to have _group for each "bendable" node and parented under the "root" with the UDP strings assigned to the root_group node like pictured below:

Available UDP's

UDP

Description

mergedmesh_deform

Needed to enable mergedmesh deform cloth physics for this node.

mergedmesh_deform_stiffness

Defines how "hard" the deformable is, between 0.0 and 1.0.

mergedmesh_deform_damping

Controls how quickly the deformable will "settle", between 0.0 and infinity.

mergedmesh_deform_variance

Controls how much randomness is in the wind sampling algorithm, between 0.0 and infinity.

mergedmesh_deform_air_resistance

Scales the wind influence, multiplied with the levels wind force.

mergedmesh_deform_air_frequency

Cosines modulated speed of wind per vertex, between 0.0 and infinity.

mergedmesh_deform_air_modulation

Cosines modulated speed of wind per wind-force, between 0.0 and infinity.

mergedmesh_deform_max_iter

Amount of simulation iterations, between 1 and 12, 3 is default, the higher the more expensive.

Example use of parameters:

mergedmesh_deform
mergedmesh_deform_stiffness = 0.9
mergedmesh_deform_damping = 0.1
mergedmesh_deform_variance = 3
mergedmesh_deform_air_resistance = 0.3
mergedmesh_deform_air_frequency = 1.67
mergedmesh_deform_air_modulation = 0.03
mergedmesh_deform_max_iter = 4

Simple Setup

  • The root object is "Cloth_Merged_Mesh_Deform" in this example.
  • All bendable nodes are linked to the root object, in this case only one called "bendable".
  • Only the root object is needed to export the object, export settings are set to "Export file per node", vertex colors are needed.
  • At least one black vertex has to be defined, to avoid that the cloth falls down.

Intermediate Setup

  • This is the only technique needed when setting up blades of grass. The others can be used in various ways.
  • This technique is similar to previous touch bending feature with branch1_1 nodes but without need for a proxy. These nodes help the system tell what parts are 'stems' and what parts will deform.
  • These nodes are either locators or helpers depending on what DCC tool is being used.
  • At least two branch nodes are needed, one labeled 'branch1_1' for the base which doesn't move and another labeled branch1_2 which depending on how many subdivisions you want can be the at the end of the geometry (opposite of the first helper/locator)
  • The amount of subdivisions can vary but generally speaking they will not surpass 3.

Complex Setup

  • The root object is "willow_c" in this example.
  • All bendable nodes are linked to the root object.

Tips

  • It's better to have an irregular and not planar shape to add more random movement and to avoid that the cloth settles too quick.
  • Can also be used on trees and other objects requiring simulation.