About ArtPath

(Updated 12/12/2019)


What is ArtPath?

ArtPath is a feature added for the first time in 4.0 to represent the main lines of an illustration.
By allowing the line texture of an illustration to be handled like a vector line material on the model, it is possible to freely deform and express changes in color tone while maintaining the texture and thickness of the line.

* The ArtPath function is only available when the target version of the model is “SDK Not Available/Cubism4.0”.
If you try to select the ArtPath function with target versions other than the above, a warning popup will appear in the lower right corner of the view area.



ArtPath Screen Structure

(1) ArtPath Tools You can create and edit new ArtPath.
(2) Locking of drawing objects Only ArtMesh and ArtPath can be shown/hidden and locked on the view.
Textures are displayed as they are.
(3) Tool Details See “Tool Details Palette” for details on the [Tool Details] palette when selecting an ArtPath.
(4) Inspector For details on the [Inspector] palette when selecting an ArtPath, please refer to the “Inspector Palette”.
(5) Show/hide ArtPaths ArtPath filter add button. It is possible to show and hide ArtPath objects in the palette.
(6)  ArtPath
The created ArtPath will be added to the Parts palette.


Nature and types of ArtPath

“LCNS” and “SNS” are used for the line generation method of the ArtPath.
Each of these changes the shape of the line even when the position of the control point is the same.
See the table below for the differences between them.

  LCNS Line SNS line
Visual differences
Behavior when moving control points


Sprite Method Drawing Mechanism

This section explains how lines are drawn when an ArtPath is drawn with a sprite method brush.
In the sprite method, which uses textures prepared with multiple brush sizes, the texture size chosen depends on the quality value of the brush setting.

The higher the quality, the higher resolution texture is selected for smaller line widths.
The lower the quality, the smaller resolution texture is selected for larger line widths.

The following are outlines of a sample model Hiyori Momose (video version), adjusted to make it easier to understand how the sprite method of rendering works.

 Quality: 5
The textures selected by the line width overlap each other,
and areas that look like overlapping ink are drawn.

  Quality: 20
It is drawn with smooth brushstrokes.

As you can see, the appearance of the lines can change depending on the quality, so we recommend that you adjust the values appropriately while looking at the actual ArtPath drawn on the campus.
For more information on the sprite method, see “ArtPath Brush Editing: Sprite Method”.


Mesh Method Drawing Mechanism

This section explains how lines are drawn when an ArtPath is drawn with a mesh method brush.
The mesh method of ArtPath lines is a little more specific in its drawing mechanism as the number of control points increases.

Below is a mesh texture that has been adjusted to make the rendering mechanism easier to understand.

The following illustration shows how the line changes with the number of control points when a straight line is drawn with this brush.

2 points (A-B)
The ratio between control points A-B will be the same as the appearance of the texture. Moving either vertex does not change the ratio of in/out.

3 points (A-B-C)

The same ratio of brush texture is used as in the 2 points, but
the ratio of in/out changes when the position of the B control point, which is in the middle, is moved.

4 points (A-B-C-D)

The first two control points A-B are set “in” and the last two points C-D are set “out”.
Between B and C, “intermediate” is shown as it is.

5 points (A-B-C-D-E)
From 5 or more points, the following mechanism is used to draw.
The first two control points A-B are set “in” and the last two points D-E are set “out”.
Between B and C, “middle” and “(reversed left and right) middle” are displayed.
Between C and D, the second and third points counting from the last, “intermediate” is displayed.

The mechanism for 6 points or more is the same as the concept for 5 points.
The first two control points are “in” between the first two control points and the last two control points are “out” between the last two control points.
The “middle” is displayed between the second and third control points counting from the last, and
“middle” and “(reversed left/right) middle” are repeated between the other control points.

For more information on mesh methods, see “ArtPath Brush Editing: Mesh Method”.


Expansion and contraction of ArtPath

ArtPath maintains their line widths even when scaled with bounding boxes or deformers.
If you want to change the line width on the model, adjust the line width setting for the control point.


In the Animator, you can set the magnification of the ArtPath width from [Placement & Opacity] in the [Properties group].


* The width set for the edge in the brush settings is maintained even if the magnification is changed.
* If the magnification is reduced until the edges touch each other, the edges will also be reduced in magnification.

About the display of ArtPath

By default, the lines of the mesh of the ArtPath itself are displayed.
The lines of this mesh can be edited in the [Tool Details] palette under [ArtPath display settings: Mesh Line Color] to make them less transparent or change their color.

Control Point Type

Control points for ArtPath that are not selected are displayed in white.
The control points of ArtPath with start and end points set are displayed in light blue.
The control points of the selected ArtPath are displayed in red.
The control points of ArtPath with broken lines are displayed in yellow.
The control points of ArtPath that have been set to follow will be pink.


How to create an ArtPath

There are two main ways to create an ArtPath.

Automatic ArtPath generation function

This is a method to reproduce the “main line” as an ArtPath on the model from data that has the “main line” and “fill” in the original PSD.
See “Automatic ArtPath Generation” for details.


Manual generation of ArtPath

This is a method for freely creating line drawings with ArtPath on the model.
For more information, see “Creating ArtPath Manually”.

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