nParticle Output Mesh attributes

Output Mesh attributes allow you to control the size, smoothness, and dynamic characteristics of Blobby Surface nParticle objects when they are converted to polygon meshes. To see the effects of Output Mesh settings, you must first convert your nParticle object to a polygon mesh (see Modify menu).

See Work with nParticle meshes.

nParticles emitted after the conversion continue to add to the size and overall appearance of the nParticle output mesh. Output Mesh attributes are applicable all Particle Render Type nParticles. However, the nParticle output mesh always creates an iso-surface, which is based on nParticle Radius and Threshold.

Note:

After your nParticle object is converted to a polygon object, Maya no longer displays the particles in the scene view. This reduces simulation time and makes it easier to see how your Output Mesh attribute adjustments affect the mesh. To make the nParticle object visible in the scene, in the Object Display section of the nParticleShape node Attribute Editor, turn off Intermediate Object.

Threshold

Determines the smoothness of the surface created by overlapping Blobby Surface nParticles. Threshold is based on the overall density of overlapping nParticles. Each nParticle has a density of 1 at its center, which then falls off to a value of 0 at the nParticle's edge.

Blobby Radius Scale

Specifies the amount nParticle Radius is scaled to create an appropriately smooth surface on Blobby Surface nParticles. Increasing Blobby Scale Radius does not affect nParticle Radius, meaning that nParticles can overlap due to Blobby Scale Radius without affecting their dynamic behavior. Increasing Blobby Scale Radius and Threshold together create smooth surfaces on nParticle output meshes.

Motion Streak

Motion Streak elongates individual nParticles based on the direction of nParticle motion, as well as the distance the nParticle travels in one time step. When Motion Streak is 0, nParticles are round. When Motion Streak is 1, nParticles are elongated to a length that is equal to the distance travelled in one time step. Motion Streak applies only to nParticles converted to nParticle output meshes. Motion Streak is useful for creating a motion blur type of effect, and for shaping the flow of Liquid Simulation effects.

Mesh Triangle Size

Determines the size of the triangles used to create the nParticle output mesh. Small Mesh Triangle Size produces high resolution output meshes with smoother surfaces. Small triangles take more computing resources and time to simulate. Mesh Triangle Size can be affected if the particle system bounds are very large relative to the set Mesh Triangle Size. See Max Triangle Resolution.

Max Triangle Resolution

Specifies the grid size that is used to create the output mesh. Max Triangle Resolution clamps the resolution of the voxel grid used in generating the nParticle output mesh's triangles. If the grid size required to create an nParticle mesh exceed the Max Triangle Resolution value, the output Mesh Triangle Size automatically increases to compensate for increasing size of the mesh.

Mesh Method

Specifies the type of polygon mesh used to generate the nParticle output mesh iso-surface. By default, Mesh Method is set to Triangle Mesh.

Triangle Mesh

Creates a cube polygon mesh using the marching cubes method.

Tetrahedra

Creates a triangle polygon mesh using the marching tetrahedra method.

Acutete Trahedra

Creates a triangle polygon mesh using the marching tetrahedra method, and produces a slightly higher resolution mesh than the Tetrahedra Mesh Method.

Quad Mesh

Creates a quad polygon mesh.

Mesh Smoothing Iterations

Specifies the amount of smoothing applied to the nParticle output mesh. Smooth iterations increase the lengths of the triangle edges, making the topology more uniform, generating a smoother iso-surface. The smoothness of your output mesh increases with increased Mesh Smoothing Iterations values, but calculation time also increases.

Color Per Vertex

When on, color per-vertex data is generated when you convert an nParticle object to an output mesh. Color per-vertex data is derived from the nParticle object's per-particle color values. The data is color set data and can be applied to the nParticle output mesh like other color set data.

Opacity Per Vertex

When on, opacity per-vertex data is generated when you convert an nParticle object to an output mesh. Opacity per-vertex data is derived from the nParticle object's per-particle opacity values. The data is color set data and can be applied to the nParticle output mesh like other color set data.

Incandescence Per Vertex

When on, incandescence per-vertex data is generated when you convert an nParticle object to an output mesh. Incandescence per-vertex data is derived from the nParticle object's per-particle incandescence values. The data is color set data and can be applied to the nParticle output mesh like other color set data.

Velocity Per Vertex

When on, velocity per-vertex data is generated when you convert an nParticle object to an output mesh. Velocity per vertex is derived from the internal mapping of nParticle velocity values to R, G, and B color values. You can use velocity per-vertex data to create motion blur when the mesh is rendered using mental ray for Maya renderer.

Velocity per-vertex data is passed to the output mesh through the polySurfaceShape node's color set named Motion Vector Color Set. By default this color set uses the velocityPV data generated from the nParticle object.

Uvw Per Vertex

When on, UVW texture coordinates are generated when you convert an nParticle object to a polygon mesh. The texture coordinates let you map a texture to the surface of your output mesh.

You may need modify the meshes' UVs to get the desired placement of the texture on the mesh. You can view and edit UVs using the UV Texture Editor. For more information about UVs, see Mapping UVs and UV Texture Editor overview.

Use Gradient Normals

When on, user normals are created for the output mesh. The normals are based on the direction of the opacity gradient within the particle density. This can improve the appearance and smoothness of the nParticle output mesh, particularly in areas of the mesh that have thin triangles. This setting only affects the output nParticle mesh and not volume nParticle renders.