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Laplacian Smooth Normals Modifier Parameters

This section describes the inputs of the Laplacian Smooth Normals modifier and suggested settings.

!Laplacian Smooth Normals Modifier

Input Attribute Toggle

Several parameters mention the "Input Attribute Toggle" button. This button allows you to use a Vertex Group or Color Attribute to control the parameter's effect on different parts of your mesh. When enabled, you'll be able to select the attribute to use.

Global Options

Apply Object Transforms

Applies Object Rotation and Scale to the Normals. When using Preview Custom Normals, this is done automatically by Blender’s Custom Normal System so this is redundant. If the Normals are being used as an Attribute instead, this should be turned on. (Automatic handling of this by the addon will be added in the future. Then it will no longer be necessary to disable this.)

Geometry

The Normals are calculated on a copy of the mesh and then set on the original. These geometry changes influence the Normals, but will not change the final mesh. Note that any quad faces are also triangulated for the calculation.

Edge Splitting

Same as the Blender Edge Split modifier

Weld

Same as the Blender Weld Modifier

Triangulation Method

Same as the Blender Triangulation Modifier

Weighted Normals

Invert Area Weights

Compensates for differences in face sizes and loop spacing as described in the Explanation. Good for smooth surfaces and organic shapes. When disabled, instead emphasizes larger faces like the typical Weighted Normals modifier. Good for hard surface areas that need to preserve planar faces. The Input Attribute Toggle button allows this to be controlled by a Vertex Group or Color Attribute, so you can have both behaviors in the same mesh.

Normal Factor (formerly Normal Mask)

Mixes between the Weighted Normals and default un-weighted Normals. Setting to 0 effectively disables the Weighted Normals.

Laplacian Smoothing

Smooth Iterations

The number of times to smooth. To avoid performance problems, can only be scrubbed or clicked to 6 in the UI. A higher number can be entered by clicking into the field. The number is capped at 9 in the nodes by default, but this can be changed by editing the nodes (an option to manage this from the Addon panel is planned.) Each extra iteration has the same performance cost, but the smoothing effect is less and less. Turning it up to a very high level won’t necessarily accomplish much more than a few iterations. Usually only 1 or 2 are needed to fix shading issues. More may be needed to make huge changes to a shape, but due to the diminishing returns other methods should be considered if the number is getting past 9.

Iteration Strength

The Strength Factor per iteration. Each iteration mixes the current value with a weighted average of the neighboring vertices multiplied by this value. Turning this down slightly can also help avoid stability errors (outlier high values that can occur on very small faces in some situations). The Input Attribute Toggle button allows this to be controlled by a Vertex Group or Color Attribute.

Boundary Strength Fac

Multiplies the Iteration Strength on Boundary Vertices. Smoothing boundaries can have undesirable results, or be redundant with Extrapolate Boundaries. Recommend to use 0 or a low value when Extrapolating Boundaries, and 1 otherwise. Neither will perfectly solve boundaries, but different configurations work in different mesh situations.

Smooth Mix Factor

The mix between the Unsmoothed and Smoothed Normals. Reducing the overall mix produces a different effect from reducing the Iteration Strength due to the diminishing returns of each iteration. Can also be used conveniently for Masking. The Input Attribute Toggle button allows this to be controlled by a Vertex Group or Color Attribute.

Extrapolate Boundaries

Factor

Controls the strength of the boundary extrapolation.

Corner Smooth Strength

Smooths Boundary Corners based on the mask defined by the next two parameters. The Boundary Extrapolation is imprecise on corner vertices. This smoothing can help achieve better results, but the exact amount needed various.

Mask Corner by Angle

Detects Boundary Corners based on boundary edge angles. Vertices with connected edges below the threshold will be selected. 0 selects all boundaries, 90 selects all.

Add Corner Mask

Adds a selection to the Boundary Corner Mask. Use with a Vertex Group.

Debug

Show Evaluation Geo

Shows the Geometry that the Normals are actually calculated on with any edge splits and triangulation created by the modifier. Always used when using Show as Position or Visualize Boundary Extrapolation.

Show as Position

Smooths the Position instead of the Normals. Use this to check for unusual behavior or instability (spikes or exploding mesh at high iterations). This is technically the typical use of Laplacian Smoothing. But note that this doesn’t take the Weighted Normals into account, so it is not a “true” representation of them.

Visualize Boundary Extrapolation

Creates geometry on boundary edges that shows the curvature extrapolation. This geometry is the Extrapolated Normal rotated around the boundary edge by 90 degrees. It is made from the extrapolated Normals, not used to calculate them. It has no material assigned, and so will have the default black diffuse shader. Uses Normal Scale for size.

Visualize Normals

Instances lines onto each Normal matching its direction like the option in Edit Mode. Note that if there are other modifiers after this that alter the geometry, these extra instances may cause them problems.

Normal Scale

Scales the visualized Normals.

This section will be updated with recommended settings for different types of meshes.