Grease Pencil View Port/render artifacts while camera movement in #63452

New Issue

ChristopherAnderssarian · 2019-04-10T09:34:35+02:00

(Deleted) commented

2019-04-10 09:34:35 +02:00

(Migrated from localhost:3001)

System Information
Operating system: Windows-10-10.0.14393 64 Bits
Graphics card: Intel(R) HD Graphics 4400 Intel 4.3.0 - Build 20.19.15.4835

Blender Version
Broken: version: 2.80 (sub 54), branch: master (modified), commit date: 2019-04-07 15:02, hash: 75f551faca
Worked: (optional)

Short description of error
In some cases like in the scene from attached blend file there seems to be a problem with rendering lines perpendicular to camera. As it can be seen the lines seem to appear merged at vanishing point even though they are far apart. this is happening both in view port and rendering.
Changed different parameters for camera line lens etc + also moved camera around but the problem still remains.

Test.blend

**System Information** Operating system: Windows-10-10.0.14393 64 Bits Graphics card: Intel(R) HD Graphics 4400 Intel 4.3.0 - Build 20.19.15.4835 **Blender Version** Broken: version: 2.80 (sub 54), branch: master (modified), commit date: 2019-04-07 15:02, hash: `75f551faca` Worked: (optional) **Short description of error** In some cases like in the scene from attached blend file there seems to be a problem with rendering lines perpendicular to camera. As it can be seen the lines seem to appear merged at vanishing point even though they are far apart. this is happening both in view port and rendering. Changed different parameters for camera line lens etc + also moved camera around but the problem still remains. ![Render.png](https://archive.blender.org/developer/F6926707/Render.png) ![ViewPort Glitches.gif](https://archive.blender.org/developer/F6926709/ViewPort_Glitches.gif) [Test.blend](https://archive.blender.org/developer/F6926710/Test.blend)

(Deleted) commented

2019-04-10 09:34:35 +02:00

(Migrated from localhost:3001)

Added subscriber: @(Deleted)

ChristopherAnderssarian commented

2019-04-10 11:03:06 +02:00

Added subscriber: @ChristopherAnderssarian

ChristopherAnderssarian commented

2019-04-10 11:03:06 +02:00

I get even worse glitching when animating the camera:

Output0001-0250.mkv

Test_modified.blend

Though I think this a known limitation... @antoniov?

I get even worse glitching when animating the camera: [Output0001-0250.mkv](https://archive.blender.org/developer/F6927070/Output0001-0250.mkv) [Test_modified.blend](https://archive.blender.org/developer/F6927075/Test_modified.blend) Though I think this a known limitation... @antoniov?

ChristopherAnderssarian commented

2019-04-10 12:32:01 +02:00

Added subscriber: @antoniov

matc commented

2019-04-11 02:54:23 +02:00

Added subscriber: @matc

matc commented

2019-04-11 02:54:23 +02:00

@pattamp In case you are looking for a workaround. When I subdivide the red stroke a few times, the problem seems to go away.

Antonio Vazquez was assigned by Sebastian Parborg

2019-04-11 10:59:14 +02:00

matc commented

2019-04-11 22:25:30 +02:00

I found a possible fix for this. Not sure if it will cause other problems, but appears to be working in 3D view and when rendering.

diff --git a/source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl b/source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl
index 1ebb6797f63..aa38ff26a62 100644
--- a/source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl
+++ b/source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl
@@ -84,6 +84,9 @@ void main(void)
 	if (sp2.x < -area.x || sp2.x > area.x) return;
 	if (sp2.y < -area.y || sp2.y > area.y) return;
 
+	/* culling behind camera */
+	if (P1.w < 0 || P2.w < 0) return;
+
 	/* determine the direction of each of the 3 segments (previous, current, next) */
 	vec2 v0 = normalize(sp1 - sp0);
 	vec2 v1 = normalize(sp2 - sp1);

I found a possible fix for this. Not sure if it will cause other problems, but appears to be working in 3D view and when rendering. ``` diff --git a/source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl b/source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl index 1ebb6797f63..aa38ff26a62 100644 --- a/source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl +++ b/source/blender/draw/engines/gpencil/shaders/gpencil_stroke_geom.glsl @@ -84,6 +84,9 @@ void main(void) if (sp2.x < -area.x || sp2.x > area.x) return; if (sp2.y < -area.y || sp2.y > area.y) return; + /* culling behind camera */ + if (P1.w < 0 || P2.w < 0) return; + /* determine the direction of each of the 3 segments (previous, current, next) */ vec2 v0 = normalize(sp1 - sp0); vec2 v1 = normalize(sp2 - sp1); ```

Antonio Vazquez commented

2019-04-12 08:59:14 +02:00

@matc It makes sense... I'm going to test with several files to see if nothing else is broken.

blender-admin commented

2019-04-12 09:09:37 +02:00

This issue was referenced by 0ee23d0f5f

This issue was referenced by 0ee23d0f5f613c4418a3ab2b2c67d47b936350de

Antonio Vazquez commented

2019-04-12 09:10:05 +02:00

Changed status from 'Open' to: 'Resolved'

Antonio Vazquez closed this issue

2019-04-12 09:10:05 +02:00

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Grease Pencil View Port/render artifacts while camera movement in #63452