VSE shading mode ignores Grease Pencil Vertex colors #86956

New Issue

Ivan Cappiello · 2021-03-26T09:06:41+01:00

Ivan Cappiello commented

2021-03-26 09:06:41 +01:00

System Information
Operating system: Darwin-20.3.0-x86_64-i386-64bit 64 Bits
Graphics card: AMD Radeon Pro 5500M OpenGL Engine ATI Technologies Inc. 4.1 ATI-4.2.15

Blender Version
Broken: version: 2.92.0, branch: master, commit date: 2021-02-24 16:25, hash: 02948a2cab
Worked: N.A.

Short description of error
If a blender scene is added in the VSE, the shading mode is respected for 3D objects vertex colors but not for GP objects

Exact steps for others to reproduce the error
Open the attached blender file and switch between the "3D" scene and "EDIT" scene. In the 3d viewport of 3D scene both the cube and the grease pencil stroke are shaded correctly, in the VSE EDIT scene the cube shows the correct vertex colors and the GP is flat shaded without colors.
Side Note: using the "override scene settings" and forcing the workbench engine on the EDIT scene to respect vertex color and flat shade, makes no difference.

LINKED_GP_VSE_SCENE.blend

GP_issue_VSE.mov

**System Information** Operating system: Darwin-20.3.0-x86_64-i386-64bit 64 Bits Graphics card: AMD Radeon Pro 5500M OpenGL Engine ATI Technologies Inc. 4.1 ATI-4.2.15 **Blender Version** Broken: version: 2.92.0, branch: master, commit date: 2021-02-24 16:25, hash: `02948a2cab` Worked: N.A. **Short description of error** If a blender scene is added in the VSE, the shading mode is respected for 3D objects vertex colors but not for GP objects **Exact steps for others to reproduce the error** Open the attached blender file and switch between the "3D" scene and "EDIT" scene. In the 3d viewport of 3D scene both the cube and the grease pencil stroke are shaded correctly, in the VSE EDIT scene the cube shows the correct vertex colors and the GP is flat shaded without colors. Side Note: using the "override scene settings" and forcing the workbench engine on the EDIT scene to respect vertex color and flat shade, makes no difference. [LINKED_GP_VSE_SCENE.blend](https://archive.blender.org/developer/F9910358/LINKED_GP_VSE_SCENE.blend) ![3Dview.png](https://archive.blender.org/developer/F9910282/3Dview.png) ![VSE.png](https://archive.blender.org/developer/F9910285/VSE.png) [GP_issue_VSE.mov](https://archive.blender.org/developer/F9910273/GP_issue_VSE.mov)

Ivan Cappiello commented

2021-03-26 09:06:41 +01:00

Added subscriber: @icappiello

Ivan Cappiello commented

2021-03-26 09:07:23 +01:00

Added subscribers: @Jeroen-Bakker, @antoniov

Philipp Oeser commented

2021-03-26 10:11:52 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-03-26 10:11:52 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Philipp Oeser commented

2021-03-26 10:11:52 +01:00

To make sure we are all on the same page (and speed up the triaging/fixing process), please always provide the example .blend file where this happens.

Ivan Cappiello commented

2021-03-26 10:48:53 +01:00

In #86956#1136627, @lichtwerk wrote:
To make sure we are all on the same page (and speed up the triaging/fixing process), please always provide the example .blend file where this happens.

@lichtwerk Sorry! The blend upload failed. should be fixed now.

> In #86956#1136627, @lichtwerk wrote: > To make sure we are all on the same page (and speed up the triaging/fixing process), please always provide the example .blend file where this happens. @lichtwerk Sorry! The blend upload failed. should be fixed now.

Ivan Cappiello commented

2021-03-31 09:01:37 +02:00

Changed status from 'Needs User Info' to: 'Needs Triage'

Germano Cavalcante commented

2021-04-01 22:47:58 +02:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2021-04-01 22:47:58 +02:00

Changed status from 'Needs Triage' to: 'Confirmed'

Germano Cavalcante commented

2021-04-01 22:47:58 +02:00

I can confirm.
The Grease Pencil object, which should be green, is white in the VSE.

I can confirm. The Grease Pencil object, which should be green, is white in the VSE.

Jeroen Bakker self-assigned this 2021-05-20 09:22:24 +02:00

Jeroen Bakker commented

2021-05-20 09:22:24 +02:00

Will assign this issue to me to investigate next week. Not sure about the cause and not really familiar GP code base.

Antonio Vazquez commented

2021-05-20 16:16:56 +02:00

@Jeroen-Bakker Let me know if you need my help.

Antonio Vazquez commented

2021-05-20 16:23:00 +02:00

My guess is the problem looks related to how the shading Solid mode is used in the Linked scene. In the original, the shading is Solid->Vertex, but in the linked, it looks Solid->Singleand it's not using the original scene setup.

My guess is the problem looks related to how the shading Solid mode is used in the Linked scene. In the original, the shading is `Solid->Vertex`, but in the linked, it looks `Solid->Single`and it's not using the original scene setup.

blender-admin commented

2021-05-25 15:10:46 +02:00

This issue was referenced by baa7a53974

This issue was referenced by baa7a5397486f6fad9e8e8ffc4852776940c4392

blender-admin commented

2021-05-25 15:10:46 +02:00

This issue was referenced by a20ef4207d

This issue was referenced by a20ef4207d46a28c869f8953c5ecf0f5b7af1984

Jeroen Bakker commented

2021-05-25 15:11:09 +02:00

Narrowing down the issue is in a parameter used in the vertex shader. the finalColorAdd uses 1.0.
Seems like vertexColorOpacity contains an incorrect value (0 in stead of 1).

this is read from pd->vertex_paint_opacity which uses draw_ctx->v3d->overlay.gpencil_vertex_paint_opacity.

This property isn't set when performing opengl rendering.

Finally...
root cause there is no known default for gpencil_vertex_paint_opacity.

Code is really confusing.
is_render in grease pencil means that it shading is in render mode. We cannot add exceptions there when rendering images as that would also intervene with viewport rendering where it is not expected.

although the comments says something else...

/* If we are rendering for final render (F12). */
  bool is_render;

  const bool override_vertcol = (pd->v3d_color_type != -1);
  const bool is_vert_col_mode = (pd->v3d_color_type == V3D_SHADING_VERTEX_COLOR) ||
                                GPENCIL_VERTEX_MODE(gpd) || pd->is_render;
  float vert_col_opacity = (override_vertcol) ?
                               (is_vert_col_mode ? pd->vertex_paint_opacity : 0.0f) :
                               pd->is_render ? gpl->vertex_paint_opacity :
                                               pd->vertex_paint_opacity;

Added a hack...

Narrowing down the issue is in a parameter used in the vertex shader. the finalColorAdd uses 1.0. Seems like vertexColorOpacity contains an incorrect value (0 in stead of 1). this is read from `pd->vertex_paint_opacity` which uses draw_ctx->v3d->overlay.gpencil_vertex_paint_opacity. This property isn't set when performing opengl rendering. Finally... root cause there is no known default for gpencil_vertex_paint_opacity. Code is really confusing. is_render in grease pencil means that it shading is in render mode. We cannot add exceptions there when rendering images as that would also intervene with viewport rendering where it is not expected. although the comments says something else... ``` /* If we are rendering for final render (F12). */ bool is_render; ``` ``` const bool override_vertcol = (pd->v3d_color_type != -1); const bool is_vert_col_mode = (pd->v3d_color_type == V3D_SHADING_VERTEX_COLOR) || GPENCIL_VERTEX_MODE(gpd) || pd->is_render; float vert_col_opacity = (override_vertcol) ? (is_vert_col_mode ? pd->vertex_paint_opacity : 0.0f) : pd->is_render ? gpl->vertex_paint_opacity : pd->vertex_paint_opacity; ``` Added a hack...

Jeroen Bakker commented

2021-05-25 15:18:44 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Jeroen Bakker closed this issue

2021-05-25 15:18:44 +02:00

Jeroen Bakker commented

2021-05-25 15:21:14 +02:00

@antoniov please check my solution. It shows a design flaw in the grease pencil drawing. Question remains when to use which opacity setting. Current implementation might not match what users expect.

Antonio Vazquez commented

2021-05-25 16:21:25 +02:00

@Jeroen-Bakker I will check.

Antonio Vazquez commented

2021-05-25 16:28:51 +02:00

@Jeroen-Bakker It looks your fix is correct. The root cause is the versioning code is not fixing this value for some reason:

/* Init default Grease Pencil Vertex paint mix factor for Viewport. */
if (!DNA_struct_elem_find(
fd->filesdna, "View3DOverlay", "float", "gpencil_vertex_paint_opacity")) {
LISTBASE_FOREACH (bScreen *, screen, &bmain->screens) {
LISTBASE_FOREACH (ScrArea *, area, &screen->areabase) {
LISTBASE_FOREACH (SpaceLink *, sl, &area->spacedata) {
if (sl->spacetype == SPACE_VIEW3D) {
View3D *v3d = (View3D *)sl;
v3d->overlay.gpencil_vertex_paint_opacity = 1.0f;
}
}
}
}
}````


But, anyway, the real fix is what you did adding a default value of 1.0 to this value. Thanks for catch up this bug ;-)

@Jeroen-Bakker It looks your fix is correct. The root cause is the versioning code is not fixing this value for some reason: ```if (!MAIN_VERSION_ATLEAST(bmain, 283, 7)) { ``` /* Init default Grease Pencil Vertex paint mix factor for Viewport. */ if (!DNA_struct_elem_find( fd->filesdna, "View3DOverlay", "float", "gpencil_vertex_paint_opacity")) { LISTBASE_FOREACH (bScreen *, screen, &bmain->screens) { LISTBASE_FOREACH (ScrArea *, area, &screen->areabase) { LISTBASE_FOREACH (SpaceLink *, sl, &area->spacedata) { if (sl->spacetype == SPACE_VIEW3D) { View3D *v3d = (View3D *)sl; v3d->overlay.gpencil_vertex_paint_opacity = 1.0f; } } } } }```` ``` But, anyway, the real fix is what you did adding a default value of 1.0 to this value. Thanks for catch up this bug ;-)

Jeroen Bakker commented

2021-05-25 16:55:33 +02:00

When overriding in a scene you don't have the overlay options. previously when creating a new 3d view the defaults were not set. But that is not related to this issue. I just fixed it as I came across it.

The second commit is the hacky fix. Personally I find this part of the code/design does not communicate when which vertex paint opacity should be used, there are just to many exceptions.

When overriding in a scene you don't have the overlay options. previously when creating a new 3d view the defaults were not set. But that is not related to this issue. I just fixed it as I came across it. The second commit is the hacky fix. Personally I find this part of the code/design does not communicate when which vertex paint opacity should be used, there are just to many exceptions.

Falk David referenced this issue

2023-02-10 13:03:23 +01:00

Blender LTS: Maintenance Task 2.93 #88449

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2024-03-23 00:33:49 +01:00

Fix #118260: Scene strip wireframe display #119811

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2024-03-24 08:53:03 +01:00

Fix #118260: VSE scene strip wireframe display

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