1. Go to a frame that contains as many details as possible.

2. Change Method to Average Position. The preadjusted Spherical mode might be slow.

3. Start with Particle Separation. The value should be at least the same as the Vellum Configure Grains SOP node’s Particle Size. Smaller values create more details, but also more polygons.

4. A moderate increase of Influence Scale may help to smooth the surface and close smaller holes. The same applies to Droplet Scale.

5. Instead of playing with Influence Scale and Droplet Scale consider filtering. Filters like Dilate or Smooth also help to improve mesh quality, but they are faster and less memory-intensive.

• The default Voxel Scale value gives good results in many situations.

• The value will be multiplied with Particle Separation to define a VDB voxel’s edge length.

• For example, with Particle Separation set to 0.015 and a Voxel Scale of 0.5, the edge length will be 0.0075.

1. Turn on the Particle Fluid Surface SOP’s Display/Render tag to visualize the surface.

2. Turn on the Template tag of the node that is connected to the Particle Fluid Surface SOP’s first input.

• Increase the number of particles by decreasing the Vellum Configure Grains SOP node’s Particle Size.

• Use the Particle Fluid Surface SOP node’s Dilate filter.

• Moderately decrease the Particle Fluid Surface SOP’s Influence Scale and Droplet Scale values.

• The more particles, the better the surface mesh will turn out. Decrease the Vellum Configure Grains SOP’s Particle Size value to get more particles.

• Decrease the Particle Fluid Surface SOP’s Particle Separation to get more details.

• The same applies to the number of polygons, because more polygons help to represent smaller structures like droplets or thin tendrils.

• The Vellum Configure Grains SOP’s Packing Density helps to get a better representation of the sourcing object. Note that this attribute should only be used with Vellum fluids.

• Filters are a good and fast way to fine-tune the surface.

Some attributes are transferred to the surface by default, for example velocity (v) and vorticity. Custom attributes can be added as well:

1. Create the attribute, for example through an Attribute Wrangle SOP node.

2. Make sure that the node that creates the attribute is placed before the Particle Surface Fluid SOP.

3. Go to the Particle Surface Fluid SOP’s Transfer Attributes and append the previously created attribute to the list.

4. Use Attribute Radius and Attribute Samples to smooth the attribute values. This is often necessary to enhance motion blur quality.

1. In the Particle Fluid Surface SOP, go to Surfacing ▸ Output and make sure that Transfer Attributes is turned on. Look for the v entry.

2. From Visualize select Velocity.

3. Adjust Velocity Range to get the full color spectrum from the Velocity Ramp.

You can optionally subtract geometry from the generated surface before it is converted to polygons. For example, you can prevent the node from generating polygons outside the fluid’s container object, or within objects the fluid is colliding with.

1. Connect the volumes/geometry you want to subtract from the surface to this node’s second input (“Collision objects and volumes”).

2. In the parameter editor, click the Regions tab and turn on Subtract collision volumes.