Grease Pencil Bézier Stroke Type

Blender 2.92 introduced curves for Grease Pencil with the Curve Edit Mode. This work is meant to expand the idea to all areas of Grease Pencil.

Disclaimer: Keep in mind that this branch is in an experimental stage and a work-in-progress. Do not use it in production.

The idea

The basic concept is that strokes can now have a type. Previous strokes are now called Poly Strokes and strokes of the new type are called Bézier Strokes. This system allows Curve Edit Mode to be merged into normal Edit Mode.

You can convert between stroke types at any point. This is done through the Set Stroke Type operator. Just select the strokes you want to convert and set their type.

In general, everything that can be done with Poly Strokes should also be possible with Bézier strokes. This includes editing, sculpting, drawing, vertex painting, and weight painting.

Drawing

There will be multiple ways of drawing Bézier strokes directly, one of which is a new tool: the Bézier Pen.

bezier_pen_icon

A freehand curve drawing tool is also planned (e.g. there will be a brush-setting that allows you to set the stroke type to draw with).

Sculpting

Bézier strokes can be sculpted just like Poly strokes. The current implementation updates the entire curve, but this will change in the near future.

The same will be possible for vertex and weight painting. However, this is not yet implemented.

Modifiers

Not all modifiers are supported yet, but the goal is to have all modifiers working for both stroke types at some point.

Armature modifier demo:

Documentation

Since this branch is still in an experimental stage, features, short-cuts, UI names and layout might all change over time. For that reason, we don’t have a manual or documentation yet. If you have questions you can ask them on blender.chat or in this thread.

The goal of this thread

This thread is meant for the community to try out the branch and share their experiments with it. You are welcome to share what you have done with the branch, what problems you encountered, what worked well, etc. Please keep all comments and discussions on topic and please do not use this thread to request features. Thank you.

Download link and updates:

All the development is happening on the branch named: temp-gpencil-bezier-stroke-type.

Download link: https://builder.blender.org/download/temp-gpencil-bezier-stroke-type (updated manually).

Development task: https://developer.blender.org/T85754 (updated to the latest development status).

14 Likes

Oh, this isn’t a request! We are working on it already!

2 Likes

Hi, this is great change, this new stroke type, I have tested with latest build, and I think is also is good having the same control points generated by setting the stroke type as a bézier, when you convert the grease pencil into curve object of the same type like what I have done with the conversion below shown in the images. But the conversion between the same type from Grease-pencil bézier with the optimal control vertexes but when is converted I have many control vertexes from the conversion as a Bézier curve as you can see in the example. and this make a almost impossible to handle this curves, I know there is other option such as the threshold but that don’t make the same beautiful results as the original source.

this is a bitmap image traced into Grease Pencil and I have changed the stroke type into bézier, and you can see the optimal control vertex and the sharp corner.

And this is the conversion of the same Grease pencil into a curve Object as a bézier.
Is visible the incredible amount of control points

Anyway this capability is well preserved when grease pencil as exported into SVG.
Thanks.

2 Likes

When I saw the bottom image, I thought those were stroke (poly) points at first. This is definitely not intentional, will look into it.

1 Like

Hi, If you have time, I have an other request if this can be possible, there is a way to maintain and preserve the same curve type from the conversions of a Blender curves object into Grease Pencil stroke?
Below two image that can illustrate what happen the curves lose their original control vertices and they are converted as a polyline interpolate with many control vertex.
Thanks.

Blender various curves type.

Curve when they are converted into GP objects

Yes, this is part of the plan! Just haven’t gotten to it yet. Any curve that is converted or imported should be automatically of the bézier stroke type.

1 Like

Wow that is fantastic thing.