New Rotation attributes let you control how Nucleus drives nParticle rotations on a per-particle basis. Rotation attributes can also be used to rotate instanced geometry. Rotation Friction and Rotation Damp attributes let you control the rate of particle rotations.

Per-particle rotations are useful for creating realistic, randomly moving objects such as flying debris in an explosion effect.

Watch: nParticle Rotation

• nParticle Rotation
• Rotation
• Rotate instanced geometry

nParticles now includes internal per-particle ramps for collision attributes. You can use Collision Ramps to set per-particle Collide Strength, Bounce, Friction, and Stickiness on nParticle objects, and scale attribute values based on nParticle properties such as age, radius, or speed.

• Collision Ramps
• nParticle internal ramps and per-particle attributes

A new Surface Tension attribute lets you add realistic surface tension to your nParticle liquid simulations. In nature, surface tension is the attractive force between the molecules of liquids, and is most noticeable in phenomena such as the formation of water beads or liquid droplets on surfaces. Surface Tension mimics this characteristic by creating contracting and expanding behavior on the surface of a liquid nParticle object as it moves.

A Surface Tension Scale internal ramp lets you set Surface Tension on a per-particle basis.

• Surface Tension
• Surface Tension Scale
• Liquid Simulations

Maya 2011 includes a Viscosity Scale ramp that lets you set per-particle Viscosity values of your liquid simulation nParticles. Using the Viscosity Scale ramp, you can scale Viscosity values based on nParticle properties such as age, radius, or speed.

• Viscosity Scale
• Liquid Simulations

You can now add nConstraints to nParticles that are emitted into your scene after initial state. For example, you can add a Component to Component constraint to emitted nParticles to create a continuous chain of connected particles.

In previous versions of Maya, only initial state nParticles can have constraints.

• Constraining Nucleus objects
• Create and Edit nParticle Constraints

Maya 2011 includes performance improvements when converting an nParticle object to a polygon object. These improvements are most noticeable when using Triangle Mesh or Quad Mesh as the Mesh Method.

In Maya 2010, meshes output as quads (Mesh Method set to Quads) may have issues with non-manifold geometry or spikes in the areas joining the separate lobes of the isosurface. Many of these problems have been fixed in Maya 2011. Also, the initial quad surface generated by the mesh conversion is now smoother, even when Mesh Smoothing Iterations are set to 0.

• nParticle output meshes
• Convert nParticles to polygons

You can now generate per-vertex color, opacity, and incandescence data when you convert an nParticle object to a polygon mesh. When on, Color Per Vertex, Opacity Per Vertex, and Incandescence Per Vertex generate per-vertex data which is derived from the nParticle object's per-particle color, opacity, and incandescence values. The output mesh per-vertex data can be used as color set data and applied to the polygon object like other color set data.

Watch: nParticle Per Vertex Color

• Output mesh per-vertex shading
• Set nParticle output mesh properties
• Output Mesh

You can now create motion blur when you render nParticle output meshes. A new Velocity Per Vertex attribute generates velocity per vertex data when an nParticle object is converted to an output mesh. When you render your nParticle output mesh using mental ray for Maya, velocity per-vertex data is used for rendering with motion blur.

• Create motion blur
• Velocity Per Vertex

You can now generate a UVW coordinate system for your nParticle output meshes. A new Uvw Per Vertex attribute outputs UVW coordinates when an nParticle object is converted to an output mesh. You can use the coordinates to assign textures to nParticle output meshes.

You can use the UV Texture Editor to modify the output meshes' UV topology like any other polygon surface.

• Uvw Per Vertex