2023-12-04 Grease Pencil Module Meeting

Meetings
1

Date/Time: 2023-12-04T15:00:00Z
Link: https://meet.google.com/xxo-tyin-rem
Attendees :

  • Amélie Fondevilla (LFS, Developer)
  • Antonio Vazquez (Developer)
  • Casey Bianco-Davis (Developer)
  • Falk David (Blender developer)
  • Matias Mendiola (Grease Pencil core team)
  • Nick Fox-Gieg (York University)
  • Samuel Bernou (ADV Studio, Python dev)

Topics

  • Development updates

Meeting Notes

Show all commits
  • Notes of a rendering meeting (2023-11-21, Brecht, Clément, Falk):
    • We discussed four major points:
      1. Is there a good reason for having a separate renderer for Grease Pencil ? Is this similar to the question “how do we do NPR rendering in Blender” ?
      • Yes. There is an ongoing discussion with dillongoo studios about NPR rendering in Blender. There is a possibility that an NPR engine would render grease pencil as well, thus replacing the current renderer. Everyone agreed that having a separate engine for grease pencil is limiting and we should find a better solution.
      1. Anti-aliasing issue
      • Clément: This can be solved similarly to how the workbench engine deals with aliasing. Some “jittering” approach could be implemented. This would be likely for after GPv3 is completed.
      1. Batch cache for rendering performance issue
      • Passing the attributes directly is possible, but would require some rewrites of the engine.
      1. Triangulation for rendering issue
      • It’s unclear if this is a bottleneck - would have to be investigated further.
  • Nick: Doesn’t the Geometry Node support already allow us to ‘render’ grease pencil in other engines?
    • Falk: Technically yes, but it requires meshing the curves and then assigning a material. Grease Pencil can currently be rendered without the need for meshing. It’s all done in the shader. So that is much faster.
  • Casey: GPv2 has the ability to edit strokes using bézier curves. Will GPv3 also have this functionality?
    • Falk: One of the reasons we chose CurvesGeometry as the fundation for GPv3 was that it also is able to represent other types of curves and not only poly curves. Whether or not we can have this functionality in GPv3 is unclear. It’s not used as much so we might consider leaving it for a later release. That being said, the goal is to have native bézier support for grease pencil and the data-structure allows for it.

Next Meeting

7 Likes
2

Bezier handles not used that much? O.o

1 Like
3

From my experience, yes. I might be wrong! How do you use the curve editing feature in grease pencil?

4

They work very well for simplistic style cutout animation. Think Peppa Pig, for example.

1 Like
5

Let’s just make sure we’re talking about the same thing:
image
This is what the meeting notes are talking about. I don’t know how this relates to cutout animation. Do you mean it’s good for creating the grease pencil shapes?

6

Yeah that’s precisely what I mean.

7

it can be replaced if a bezier stroke type is introduced and available in edit mode

8

Rigth, that’s the plan anyways, but we’ll have to see if we can make that happen for when GPv3 comes out.

9

Im not 2D animator I use grease pencil mostly for visualizing stuff. I work with simple shapes and I use curve editing much more than sculpt tools.

I also teach Blender and curve editing is first thing people ask about usually. Editing points doesnt make much sense to traditional 2D artists. People who do motion graphics in grease pencil rather than character animation depend on it

1 Like
10

Off topic question: With new data type and geometry nodes, will it be possible to use GP objects as custom shapes for bones? I always liked the idea to simply draw controller shapes with brush

11

It’s not planned. I guess you can use the curve object, draw with that and convert to mesh. With a little script it could be a bit less cumbersome.

1 Like
12

Any chance of GP having it’s own file?
I would love to use GP in game engines, it’s currently very much locked inside Blender which is damn shame.

13

The dev step that I’m waiting for, before offering feedback, is for GP3 to be able to be applied via the a modifier - as is currently with the Line Art modifier.

Beyond that, it’s good to see the anti aliasing being mentioned. Render output is currently so slow and poor in quality that I purchased a particular well-known external addon.

14

I’m not sure what you mean with “it’s own file”. If you want to export the data, that should be pretty easy once we can dump the attributes of the drawing (e.g. positions, radii, etc.). Then you can format that to anything you’d like and write it to a file.

15

So there there is a chance I will be able to export Grease Pencil to GLTF like any other 3D object?

16

Sure. That’s already somewhat possible in GPv2 if you convert your strokes to curves and then to mesh. Then you can export that to glTF. Currently you won’t have fills or attributes like radius though. That will be possible in GPv3.

2 Likes
17

I think there are two common ways do to a draw/animation, that is why animation software put it in two categories

Bitmap: Ok here I will sketch, frame by frame animation, more organic, intuitive drawing, concept, brainstorm ideas
I don’t need any access to individual points or Bézier here, I don’t need that. (In this category you are right, it is not used)

Vector: more precise, think in Cartoon Network or angry birds drawing, perfect art final, motion graphic, I would call it a “technical drawing”.
Sharp and Bézier editing in anytime, it can sound weird, but we don’t need to access all individual points of a curve, only Bézier or sharp corners point (like most vector software)

I never use sculpt tools, for me it is great for 3D but weird for 2D

1 Like
18

+1 to the other replies.

I teach 2D animators how to do things in GPv2 which they learned from ToonBoom Harmony & Adobe Animate, etc. For them, Bezier curve editing is really important to create cutout shapes w/ cleanest possible lineart.

It sounds like you are planning to implement a pure bezier curve in GPv3 instead of the resampled-vertices approach? This is great, as long as they are intuitive to draw & you can convert back and forth easily.

4 Likes