Advanced Settings

The full smear nodegroup has two options for what settings are displayed, simple and advanced. There is some overlap but every setting will still be explained individually for each node group.

The simple settings are all that many people will need for many animations.

All of the capabilities are technically the same as the advanced controls, just with less control for the user which can be a good thing for fast results.

Object/Collection Settings

Every Auto Smear nodegroup has these settings, and they determine what will get smears. In almost all cases the user does not have to worry about these settings as they will be handled by the addon.

Use Vertex Group/Vertex Group

Use Vertex Group will enable the use of the Vertex Group Setting, when you check it you will see that setting stop being greyed out.

To use a vertex group, make sure you have a vertex group on the object that is being smeared, and then in the geometry nodes settings, type the exact name of the vertex group.

The menu won't auto-populate with vertex groups but as long as you type the exact name (case-sensitive) it will work.

On Twos/Offset Timing

Use these settings if you are animating on twos.

• Checking On Twos will make the smears update every even frame.
• Checking Offset Timing will offset the smear timing so that they update on every odd frame.

Smear Settings

Unchecking this panel will make smears not appear.

Max Age

How long the smears will last (in frames).

Density

The density of smears, independent of mesh resolution.

Seed

The seed of the distributions

Start Speed Threshold

The minimum distance the mesh needs to travel to smear.

End Speed Threshold

The minimum distance the mesh needs to travel to keep smearing once it has stopped.

If it starts moving slower than this value, the smear will end.

Smoothing

The method to use for smoothing the smears out.

• Fillet (Default): Rounds the corners by generating circular arcs on each point.
• Catmull Rom: Converts the smear to a catmull rom type spline.
• None: Applies no smoothing to the smear.

Radius

The max radius of the smears

Resolution

The approximate length between the points on the smears.

Trim Start/End

Trims the smear from it's start/end for more control.

This should be used if smears with a duration of 2 are still too long.

Substeps

The amount of substeps to use (Will hurt performance slightly)

This setting uses hermite spline interpolation to approximate substeps.

f-1 Influence

The influence of the previous frame's velocity on the interpolation

f Influence

The influence of the current frame's velocity on the interpolation

Smears have a minimum of 3 points per spline.

Render Method

• Grease Pencil: Render the smears as Grease Pencil splines
• Mesh: Render the smears as a mesh with normal shaders

Opacity

The opacity of the grease pencil smears

Color method

• Solid Color/Attribute: Uses a one solid color for the smears or a vertex color attribute.
• Image Texture: Uses an image texture to color the smears. Requires an image texture and UVMap to be provided.

Color Blur Iterations

How much to blur the vertex color/image texture provided. Useful for getting rid of small bright/dark areas in the provided color.

Duplicate Settings

Unchecking this panel will make duplicates not appear.

Max Age

How long the duplicates will last (in frames).

Min Surface Area

The minimum surface area that a duplicate needs to have to appear.

Speed Threshold

The minimum distance the mesh needs to travel to have a duplicate.

Velocity Blur

How many times to blur the velocity, smooths out the selection for the duplicates.

Edge Smooth

How much to smooth the edges created when splitting the mesh for the duplicates

Noise Settings

Strength

The strength of the noise displacement. Positive values displace towards the previous frame, negative values displace in the opposite direction.

Normalize

If checked the noise displacement will only go in one direction, unchecked it will go in both directions.

Scale

Scale of the base noise octave.

Detail

Number of noise octaves. This can have a fractional part, in which case a blend is performed (e.g. a Detail of 2.5 results in a 50% blend between 2 and 3 octaves).

Roughness

Blend between a smoother noise pattern and a rougher one with sharper peaks.

Noise Settings

The descriptions of these settings are from the blender docs, they are just the normal settings on a noise texture.