WIP: Surface Deform Grease Pencil Modifier - Blender 3.6 #113396

Elisabetta Abbattista · 2023-10-07T17:07:58+02:00

2023-10-07 17:07:58 +02:00

First-time contributor

Surface Deform Grease Pencil Modifier - Blender 3.6

The Surface Deform modifier allows an arbitrary mesh surface to control the deformation the Grease Pencil, essentially transferring its motion/deformation. There are two main uses for this.

Easy rigging of elaborate GP drawings. Make them follow a rigged mesh cage with clean topolgy.
Making GP drawn details follow a mesh. Frames can be added dynamically making it a powerful tool of 3D and 2D blending.

Options

The Surface Deform modifier panel.

Target

The object to which to bind.

Warning - Target Mesh Validity
While there are no restrictions with regard to the modified GP, the target object’s mesh has a few constraints, which if not followed, will prevent a successful binding:

It must not contain edges with more than two faces.
It must not contain concave faces.
It must not contain overlapping vertices (doubles).
It must not contain faces with collinear edges.

Interpolation Falloff

How much a vertex bound to one face of the target will be affected by the surrounding faces. This essentially controls how smooth the deformations are. This setting only applies when binding; it can be set differently for different frames but not changed retroactively.

Note: While lower values result in smoother deformations, they may also introduce slight artifacts.

Strength

The overall amount of influence the modifier has on deforming the GP.

Vertex Group

Allows you to define the influence per vertex (point).

Invert <->
Inverts the influence of the selected vertex group, meaning that the group now represents points that will not be deformed by the modifier.
The setting reverses the weight values of the group.

Binding Operators

Note that until a bound frame is visible, this modifier will have no effect at all. When a bound frame is visible, any change in the target mesh will deform the Grease Pencil.

When a frame is bound, on the timeline it will turn the same color of the scrubbing background to indicate it is bound and locked. The locked frame cannot be moved or removed on the timeline. To move the frame, please unbind it first.

Bound frames become greyed out.

Bind All

Each frame of the modified Grease Pencil gets bound to the state the target mesh is in that timeline frame, all layers at once.

Bind Current Frame

The current frame of the modified Grease Pencil gets bound to the state the target mesh is in the current timeline frame,all layers at once. The current frame is the Grease Pencil frame that is visible right now due to the current timeline position.

Unbind All

Executing this frees all the frames of the modified Grease Pencil from the target, and resets it to its original shape.

Unbind Current Frame

Executing this frees just the current frame of the modified Grease Pencil from the target, and resets it to its original shape. The current frame is the Grease Pencil frame that is visible right now due to the current timeline position.

Note: The GP’s are bound with regard to global coordinates, but later transformations on the objects are ignored. This means that one can freely transform the target after binding, without affecting the modified object. The modified mesh will only pick up changes to the target object’s mesh itself.

Note: The further a mesh deviates from the target mesh surface, the more likely it is to get undesirable artifacts. For this reason it is recommended to have a clean topology on the binding mesh; the topology should follow the pattern of the drawing as closely as possible.

The bake panel

The bake panel.

The purpose of this panel is to bake the deformation of the modifier on the grease pencil, creating new, unbound keyframes. All layers are baked at once.
Note: the freshly baked frames are unbound. They can be bound if desired.
This note is also the text at the bottom of the panel, to avoid any confusion.

Bake Current Frame

Bakes the frame at the current timeline position.

Bake Range

Bakes all the frame in the range specified below.

Range start

The start of the frame range to be baked.

Range end

The end of the frame range to be baked.

Fill range

Click on the clock icon at the side of the range to use the "Fill range" operator. It fills the range start and end fields with the current timeline's start and end.

Examples

Usage 1 - Mesh cage

Grease Pencil deformed by a mesh cage using the Surface Deform modifier.

Usage 2 - Follow a 3D model

This character model features drawn details in Grease Pencil. When bound to the model, they are gonna follow the deformations.

Step by step guide

Usage 1 - Mesh cage

What you need: a Grease Pencil drawing.

Add a Mesh Object in the same spot where your GP is.
Model the mesh to create a mesh cage around your drawing. The topology must be as simple as possible, and it must flow in the directions of the desired deformations. A flat surface may give best results.
Add the surface deform modifier to the GP.
Add the mesh cage as target.
Execute “Bind Current Frame” in the Surface Deform modifier panel.

The GP should now move along with your mesh cage.

Add a Armature Object in the same spot where your GP and cage are.
Create the rig that is going to deform the GP. You can use rigify and even download GP-specific metarigs.
Weight paint the mesh. You should notice how the GP moves along in the process and adjust it accordingly.
The GP is now ready for animation. You can animate it right away or link it in a scene file.

Usage 2 - Follow a 3D model

What you need: a rigged, animated character.

Create a new blank GP.
Add the surface deform modifier.
Add the mesh you want the GP to follow as target.
Select the GP and enter draw mode.
Draw the first frame.
Execute “Bind Current Frame” in the Surface Deform modifier panel.
Move along the timeline until you want to change the line.
Insert a new GP frame by either pressing i, using the context menu or turn on autokey .
Draw the new frame.
Execute “Bind Current Frame” in the Surface Deform modifier panel.
Repeat point 7-10 until the end of the animation.

Video tutorial:

coming soon

## Surface Deform Grease Pencil Modifier - Blender 3.6 The Surface Deform modifier allows an arbitrary mesh surface to control the deformation the Grease Pencil, essentially transferring its motion/deformation. There are two main uses for this. 1. Easy rigging of elaborate GP drawings. Make them follow a rigged mesh cage with clean topolgy. 2. Making GP drawn details follow a mesh. Frames can be added dynamically making it a powerful tool of 3D and 2D blending. ### Options ![immagine](/attachments/c78cef9a-5586-4993-bd6b-ca0866d06071) ###### The Surface Deform modifier panel. #### **Target** The object to which to bind. Warning - Target Mesh Validity While there are no restrictions with regard to the modified GP, the target object’s mesh has a few constraints, which if not followed, will prevent a successful binding: - It must not contain edges with more than two faces. - It must not contain concave faces. - It must not contain overlapping vertices (doubles). - It must not contain faces with collinear edges. #### **Interpolation Falloff** How much a vertex bound to one face of the target will be affected by the surrounding faces. This essentially controls how smooth the deformations are. This setting only applies when binding; it can be set differently for different frames but not changed retroactively. Note: While lower values result in smoother deformations, they may also introduce slight artifacts. #### **Strength** The overall amount of influence the modifier has on deforming the GP. #### **Vertex Group** Allows you to define the influence per vertex (point). - **Invert <->** Inverts the influence of the selected vertex group, meaning that the group now represents points that will not be deformed by the modifier. The setting reverses the weight values of the group. ### **Binding Operators** Note that until a bound frame is visible, this modifier will have no effect at all. When a bound frame is visible, any change in the target mesh will deform the Grease Pencil. When a frame is bound, on the timeline it will turn the same color of the scrubbing background to indicate it is bound and locked. The locked frame _cannot be moved or removed_ on the timeline. To move the frame, please unbind it first. ![immagine](/attachments/8facd182-55cb-4f68-945c-fef0977a53d9) ###### Bound frames become greyed out. #### **Bind All** Each frame of the modified Grease Pencil gets bound to the state the target mesh is in that timeline frame, all layers at once. #### **Bind Current Frame** The current frame of the modified Grease Pencil gets bound to the state the target mesh is in the current timeline frame,all layers at once. The current frame is the Grease Pencil frame that is visible right now due to the current timeline position. #### **Unbind All** Executing this frees all the frames of the modified Grease Pencil from the target, and resets it to its original shape. #### **Unbind Current Frame** Executing this frees just the current frame of the modified Grease Pencil from the target, and resets it to its original shape. The current frame is the Grease Pencil frame that is visible right now due to the current timeline position. Note: The GP’s are bound with regard to global coordinates, but later transformations on the objects are ignored. This means that one can freely transform the target after binding, without affecting the modified object. The modified mesh will only pick up changes to the target object’s mesh itself. Note: The further a mesh deviates from the target mesh surface, the more likely it is to get undesirable artifacts. For this reason it is recommended to have a clean topology on the binding mesh; the topology should follow the pattern of the drawing as closely as possible. ### The bake panel ![immagine](/attachments/ca389067-90b4-40b4-8792-93e1d881c113) ###### The bake panel. The purpose of this panel is to bake the deformation of the modifier on the grease pencil, creating new, unbound keyframes. All layers are baked at once. Note: the freshly baked frames are unbound. They can be bound if desired. This note is also the text at the bottom of the panel, to avoid any confusion. #### **Bake Current Frame** Bakes the frame at the current timeline position. #### **Bake Range** Bakes all the frame in the range specified below. #### **Range start** The start of the frame range to be baked. #### **Range end** The end of the frame range to be baked. #### **Fill range** Click on the clock icon at the side of the range to use the "Fill range" operator. It fills the range start and end fields with the current timeline's start and end. ### Examples **Usage 1 - Mesh cage** ![immagine](/attachments/f9d54085-96f5-44b4-bb31-db87e5348ee1) ###### Grease Pencil deformed by a mesh cage using the Surface Deform modifier. **Usage 2 - Follow a 3D model** ![immagine](/attachments/e9e387a9-1e0c-436a-bfbc-d7861b4e411d) ###### This character model features drawn details in Grease Pencil. When bound to the model, they are gonna follow the deformations. ### Step by step guide #### Usage 1 - Mesh cage What you need: a Grease Pencil drawing. 1. Add a Mesh Object in the same spot where your GP is. 2. Model the mesh to create a mesh cage around your drawing. The topology must be as simple as possible, and it must flow in the directions of the desired deformations. A flat surface may give best results. 3. Add the surface deform modifier to the GP. 4. Add the mesh cage as target. 5. Execute “Bind Current Frame” in the Surface Deform modifier panel. The GP should now move along with your mesh cage. 6. Add a Armature Object in the same spot where your GP and cage are. 7. Create the rig that is going to deform the GP. You can use rigify and even download GP-specific metarigs. 8. Weight paint the mesh. You should notice how the GP moves along in the process and adjust it accordingly. 9. The GP is now ready for animation. You can animate it right away or link it in a scene file. #### Usage 2 - Follow a 3D model What you need: a rigged, animated character. 1. Create a new blank GP. 2. Add the surface deform modifier. 3. Add the mesh you want the GP to follow as target. 4. Select the GP and enter draw mode. 5. Draw the first frame. 6. Execute “Bind Current Frame” in the Surface Deform modifier panel. 7. Move along the timeline until you want to change the line. 8. Insert a new GP frame by either pressing i, using the context menu or turn on autokey . 9. Draw the new frame. 10. Execute “Bind Current Frame” in the Surface Deform modifier panel. 11. Repeat point 7-10 until the end of the animation. Video tutorial: coming soon

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Elisabetta Abbattista added 11 commits 2023-10-07 17:08:12 +02:00

5a552ecb3c Applied patch from 3.5

279984845f stuff being now legacy

eb4725eaa1 applied a part of the patch from 3.5 that I had forgot

a04aa98253 idk trying to make it cc

f984d0521d Fully converted ops page into cc, with the help of the regular surdef file

af623e6106 operators mess

bd3ff83f15 more porting

40020cfb28 Bug fix: bake range baking all the frames as the first

fbe7be4f5a Fix: scene had to be original for changes to take effect

0d51a05823 now bound keyframes cant be moved at al!! muahahah

24e0aef0af small fix

Iliya Katushenock added this to the Grease Pencil project 2023-10-07 17:16:26 +02:00

Iliya Katushenock commented

2023-10-07 17:17:04 +02:00

Blender 3.6 is LTS currently, so i not sure if you can send new modifier in to 3.6.

Elisabetta Abbattista commented

2023-10-08 14:48:06 +02:00

First-time contributor

Blender 3.6 is LTS currently, so i not sure if you can send new modifier in to 3.6.

Hello. This patch is for use of MAD Enternatinment, I don't expect it to be added to official Blender.
However, the modifier concept may get a rework in the next few months and be potred to GP geometry nodes. Still uncertain.

> Blender 3.6 is LTS currently, so i not sure if you can send new modifier in to 3.6. Hello. This patch is for use of MAD Enternatinment, I don't expect it to be added to official Blender. However, the modifier concept may get a rework in the next few months and be potred to GP geometry nodes. Still uncertain.

Elisabetta Abbattista added 3 commits 2023-10-08 17:00:08 +02:00

eef1277fb1 Now extra unbound strokes dont get mixed up in bound strokes

21b780dfb3 Some error messages are now visible.

buildbot/vexp-code-patch-coordinator Build done. Details

4f34c8881c fixed some oversights in bind all func that caused crash

Falk David commented

2023-10-09 18:18:09 +02:00

@blender-bot build

Elisabetta Abbattista added 1 commit 2023-10-10 10:58:51 +02:00