Grease pencil over geometry occlussion problems #92052

New Issue

Daniel Salazar · 2021-10-08T19:39:46+02:00

Daniel Salazar commented

2021-10-08 19:39:46 +02:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1080 with Max-Q Design/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 472.12

Blender Version
Broken: version: 2.93.5, branch: master, commit date: 2021-10-05 12:04, hash: a791bdabd0
Broken: version: 3.0.0 Alpha, branch: master, commit date: 2021-10-06 22:38, hash: 439c9b0b84

Short description of error
GP lines get incorrect occlussion in the render while looking fine in the viewport

Exact steps for others to reproduce the error
The problem displays differently in the following 2 scenarios:

This file has a grease pencil stroke close over (but not really touching at all) a piece of geometry
GP Aliasing.blend
Viewport Rendering

Render
The line looks jagged in the render

This file has a grease pencil drawing far behind a piece of geometry
Occlussion.blend
Viewport

Render
The drawing that should be occluded is completely visible

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: NVIDIA GeForce GTX 1080 with Max-Q Design/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 472.12 **Blender Version** Broken: version: 2.93.5, branch: master, commit date: 2021-10-05 12:04, hash: `a791bdabd0` Broken: version: 3.0.0 Alpha, branch: master, commit date: 2021-10-06 22:38, hash: `439c9b0b84` **Short description of error** GP lines get incorrect occlussion in the render while looking fine in the viewport **Exact steps for others to reproduce the error** The problem displays differently in the following 2 scenarios: This file has a grease pencil stroke close over (but not really touching at all) a piece of geometry [GP Aliasing.blend](https://archive.blender.org/developer/F10883197/GP_Aliasing.blend) Viewport Rendering ![image.png](https://archive.blender.org/developer/F10883422/image.png) Render *The line looks jagged in the render* ![image.png](https://archive.blender.org/developer/F10883388/image.png) This file has a grease pencil drawing far behind a piece of geometry [Occlussion.blend](https://archive.blender.org/developer/F10883198/Occlussion.blend) Viewport ![image.png](https://archive.blender.org/developer/F10883458/image.png) Render *The drawing that should be occluded is completely visible* ![image.png](https://archive.blender.org/developer/F10883464/image.png)

Daniel Salazar commented

2021-10-08 19:39:46 +02:00

Added subscriber: @zanqdo

Antonio Vazquez commented

2021-10-08 20:13:15 +02:00

Added subscribers: @fclem, @antoniov

Antonio Vazquez commented

2021-10-08 20:13:15 +02:00

@fclem I think this is a know issue of the current Antialiasing algorithm. right?

Evan Wilson commented

2021-10-09 08:17:54 +02:00

Added subscriber: @EAW

Evan Wilson commented

2021-10-09 08:17:54 +02:00

Upon rendering the Occlusion file, there is a warning that the Combined and Z passes must be turned on to render Grease Pencil.
Turning both passes on results in the GEO correctly occluding the GP.

In the first file, adjusting the Camera's Focal Length from 195.8 mm to the default 50mm zoom (and adjusting its position to compensate) gives me the expected result. Perhaps the longer focal length is the source of unaccounted floating point precision loss?

Tested using 3.0.0 hash 886196b888

![Occlussion-Warning-GP.png](https://archive.blender.org/developer/F10895659/Occlussion-Warning-GP.png) Upon rendering the Occlusion file, there is a warning that the Combined and Z passes must be turned on to render Grease Pencil. Turning both passes on results in the GEO correctly occluding the GP. ![GP-AA-50mm.png](https://archive.blender.org/developer/F10896082/GP-AA-50mm.png) In the first file, adjusting the Camera's Focal Length from 195.8 mm to the default 50mm zoom (and adjusting its position to compensate) gives me the expected result. Perhaps the longer focal length is the source of unaccounted floating point precision loss? --- Tested using 3.0.0 hash 886196b88817

Germano Cavalcante commented

2021-10-11 15:00:38 +02:00

Changed status from 'Needs Triage' to: 'Needs Developer To Reproduce'

Daniel Salazar commented

2021-10-11 17:57:05 +02:00

In #92052#1232812, @EAW wrote:

Upon rendering the Occlusion file, there is a warning that the Combined and Z passes must be turned on to render Grease Pencil.
Turning both passes on results in the GEO correctly occluding the GP.

Thank you. I would have never noticed it there. It doesn't even print to the console. I would think the renderer would need to force render the zbuffer in this case?

> In #92052#1232812, @EAW wrote: > ![Occlussion-Warning-GP.png](https://archive.blender.org/developer/F10895659/Occlussion-Warning-GP.png) > Upon rendering the Occlusion file, there is a warning that the Combined and Z passes must be turned on to render Grease Pencil. > Turning both passes on results in the GEO correctly occluding the GP. Thank you. I would have never noticed it there. It doesn't even print to the console. I would think the renderer would need to force render the zbuffer in this case?

Ivan Cappiello commented

2021-10-15 07:55:30 +02:00

Added subscriber: @icappiello

Ivan Cappiello commented

2021-12-13 18:31:41 +01:00

@antoniov, @fclem any update about this?
The focal lenght issue is really annoying. It forces us to render a separate pass for GP in viewport render.
In 3D/2D hybrid animation wider focal lenght like 120 or even 200 are not so unusual as in other cases.

@antoniov, @fclem any update about this? The focal lenght issue is really annoying. It forces us to render a separate pass for GP in viewport render. In 3D/2D hybrid animation wider focal lenght like 120 or even 200 are not so unusual as in other cases.

Vania De Rosa commented

2021-12-14 12:04:15 +01:00

Added subscriber: @vderosa

Philipp Oeser removed the

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Grease pencil over geometry occlussion problems #92052