> For the complete documentation index, see [llms.txt](https://plugin-everything.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://plugin-everything.gitbook.io/docs/controls/pen-style/pen-shapes.md).

# Pen Shapes

`Pen Shape` selects the brush model Thicc Pro uses to draw the stroke. Choose `Round` or `Flat` for 2D stroke styles, or `Sphere (3D)` when the stroke should respond to After Effects' 3D camera.

{% hint style="info" %}
In After Effects, layers that use 3D cameras should be applied to 2D layers. To see true perspective, leave your layer as 2D but add a 3D camera and set Thicc Pro's `Pen Shape` to `Sphere (3D)`
{% endhint %}

## Pen Shapes Perspective

Whilst `Pen Shape: Round` & `Pen Shape: Flat` are capable of rendering 3D transformations they don't have any perspective; rather 3D transformations in an orthographic view. See the image below with increasing rotation each column. With 0% `Gradient Blending`, they appear to render convincing 3D... however this falls apart if we add in `Gradient Blending` in rows 3-6.

<div data-with-frame="true"><figure><img src="https://749037855-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Ftv64kPMoAtApBYU0Un9u%2Fuploads%2FIhQbqVn7MMucdXCT6iAI%2F2d%20or%203d%20extended.png?alt=media&amp;token=bc712ac8-a94d-4399-880f-aab9298462dc" alt=""><figcaption></figcaption></figure></div>

{% columns %}
{% column width="50%" %}

1. `Round Pen` no blending
2. `Flat Pen` no blending
3. `Sphere (3D)` no blending
   {% endcolumn %}

{% column width="50%" %}
4\. `Round Pen` with blending
5\. `Flat Pen` with blending
6\. `Sphere (3D)` with blending
{% endcolumn %}
{% endcolumns %}

## Pen Shape Perspective & Dashes

<div data-with-frame="true"><figure><img src="https://749037855-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Ftv64kPMoAtApBYU0Un9u%2Fuploads%2FCqFlDvcBhiuEJVtupxXV%2Fperspective%20dashes.png?alt=media&amp;token=97feebd3-537a-4d70-8016-57720067c7f4" alt=""><figcaption></figcaption></figure></div>

1. `Pen Shape: Sphere (3D)` - dashes render with perspective
2. `Pen Shape: Round` - dashes have no perspective
3. `Pen Shape: Flat` - dashes have no perspective

Since there's no perspective, even with this 3D rotation, geometry closer to the camera renders at the same width as that further away. This is clear when we add dashes, the Sphere 3D has clear perspective where the Round & Flat pen shapes don't.

If extreme width, sharp corners, or abrupt width changes produce artifacts, see [Troubleshooting strange geometry](/docs/faq.md#why-do-i-have-strange-geometry).

## Controls

<details>

<summary>Round</summary>

#### Round

`Round` uses a circular brush tip to sweep along the path. It is the default `Pen Shape`.

Because the brush tip is circular, `Butt Cap` is not available. A circular sweep always creates a rounded end profile.

Use `Round` for soft strokes, glowing paths, dotted strokes with `Round Cap`, and organic variable-width lines.

</details>

<details>

<summary>Flat</summary>

#### Flat

`Flat` uses a flat brush tip to draw the stroke. It creates straighter stroke sides and supports all three `Line Cap` options.

Use `Flat` for square-ended strokes, pill-shaped strokes, sharper technical lines, and styles where exact endings matter.

`Butt Cap` is only available with `Flat`, because the flat brush tip can end exactly at the path endpoint.

</details>

<details>

<summary>Sphere (3D)</summary>

#### Sphere (3D)

`Sphere (3D)` draws the stroke as 3D sphere geometry. It responds to the active After Effects camera, including the default composition camera when no camera layer exists.

Add a camera layer when you want explicit control over true 3D transformations and perspective.

{% hint style="warning" %}
When using `Sphere 3D`, it's very important that both your layer and compositions transformations are unified in world space! To do this, ensure your layer is set to continuous rasterization. See [Continuous rasterization and collapse transforms](/docs/faq.md#should-my-source-layer-have-continuous-rasterization-collapse-transforms-turned-on-or-off) for setup details.
{% endhint %}

When `Sphere (3D)` is selected, Thicc Pro tells After Effects that the effect uses the composition's 3D camera. Switching back to `Round` or `Flat` turns that camera dependency off. The 3D cube icon next to the effect name indicates that the effect is currently 3D camera aware:

<div data-with-frame="true"><figure><img src="https://749037855-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Ftv64kPMoAtApBYU0Un9u%2Fuploads%2F0ETIpmLNzdYpzZTkXpXS%2FScreenshot%202026-07-25%20at%204.26.47%E2%80%AFpm.png?alt=media&amp;token=d6e5f658-85ec-4958-9818-f8a49ff02fe7" alt="" width="194"><figcaption></figcaption></figure></div>

</details>

## Interactions

<details>

<summary>Line Caps</summary>

#### Line Caps

`Pen Shape: Round` supports `Round Cap` and `Projecting Cap`.

`Pen Shape: Flat` supports `Round Cap`, `Projecting Cap`, and `Butt Cap`.

`Pen Shape: Sphere (3D)` does not use the normal `Line Cap` control. Sphere rendering creates rounded stroke ends through its 3D pipeline.

See [Line Caps](/docs/controls/pen-style/line-caps.md) for cap behavior.

</details>

<details>

<summary>Line Joins</summary>

#### Line Joins

`Pen Shape: Round` and `Pen Shape: Flat` support `Miter Join`, `Round Join`, and `Bevel Join`.

`Pen Shape: Sphere (3D)` does not use the normal `Line Join` control. Sphere rendering creates rounded corners through its 3D pipeline.

See [Line Joins](/docs/controls/pen-style/line-joins.md) for join behavior.

</details>

<details>

<summary>Switching Between Round and Flat Pen Shapes</summary>

#### Switching Between Round and Flat

When switching between `Round` and `Flat`, Thicc Pro keeps the current `Line Cap` selection when that option exists in both modes.

If `Flat` is set to `Butt Cap` and you switch back to `Round`, Thicc Pro uses the previous compatible cap because `Butt Cap` is not available for a circular sweep.

</details>

## Interface Conditionals

<details>

<summary>Pen Shape</summary>

| Condition                        | Result                                                        |
| -------------------------------- | ------------------------------------------------------------- |
| `Pen Shape` is `Round`           | `Butt Cap` is unavailable                                     |
| `Pen Shape` is `Flat`            | `Round Cap`, `Projecting Cap`, and `Butt Cap` are available   |
| `Pen Shape` is `Sphere (3D)`     | `Line Cap`, `Line Join`, `Cap Limit`, and `Join Limit` hidden |
| `Pen Shape` is `Round` or `Flat` | `Miter Join`, `Round Join`, and `Bevel Join` are available    |

</details>

<details>

<summary>Sphere (3D)</summary>

`Sphere (3D)` changes which controls are available in the `Pen Style` and [Path Source](/docs/controls/path-source.md) groups.

| Condition                           | Result                                                              |
| ----------------------------------- | ------------------------------------------------------------------- |
| `Pen Shape` is `Sphere (3D)`        | `Use Light Motion Paths` is enabled                                 |
| `Pen Shape` is `Sphere (3D)`        | `Create Null` is enabled unless `Use Light Motion Paths` is checked |
| `Use Light Motion Paths` is checked | `Create Null` is disabled                                           |
| `Pen Shape` is `Round` or `Flat`    | The After Effects 3D camera flag is off                             |

</details>