Grease Pencil fill areas look divided by multiples ray lines
Closed, ResolvedPublic


System Information:
Windows 7 64bit (SP 1) - NVIDIA GeForce GTX 560

Blender Version
Broken: 2.73 release candidate 273fa0a with NVIDIA GeForce GTX 560
Worked: 2.73 release candidate 273fa0a with INTEL HD Graphics 4000

Short description of error
Grease Pencil fill areas look divided by multiples ray lines
I've tested on two computers and only looks weird on the one that use NVIDIA GeForce GTX 560

Exact steps for others to reproduce the error
Draw with grease pencil and set color fill to 1.0 with a light color to better see the problem

Matias Mendiola (mendio) updated the task description. (Show Details)
Matias Mendiola (mendio) raised the priority of this task from to Needs Triage.
Matias Mendiola (mendio) set Type to Bug.

Can you post a good and bad picture?

Cannot recreate that here using a GTX570 (Linux 64bit). First guess would be outdated graphics drivers. Can you check if you use this one?

Julian Eisel (Severin) triaged this task as Incomplete priority.Jan 6 2015, 10:39 PM

I've updated NVIDIA drivers and the problem continues.

This is the requested good/bad picture:

Aaron Carlisle (Blendify) raised the priority of this task from Incomplete to Normal.Jan 7 2015, 6:38 PM

I can confirm the same behavior on my laptop, nvidia card, using the latest drivers supplied by rpmfusion on fedora 21.
It does not happen on my desktop on fedora 20 :/

The good news is that it happens here for me too :)

I was surprised when I first noticed it, since I don't really recall seeing it initially (or maybe, I just didn't look hard enough). Anyways, I guess the best solution here is just to implement a nicer way of doing fills. The current approach using OpenGL GL_POLYGON mode was intended as an initial implementation so that we have something we can play with.

NVidia GeForce GT 740M - 331.82

@Joshua Leung (aligorith): are you planning on rolling custom tessellation code to allow PacMan? There are two algorithms used elsewhere, scanlines and ear-clipping (ideasman probably knows best)

@codemanx My preference at this stage is to reuse the method used for Lasso drawing. The only problem there is figuring out what plane to draw on / ensuring that the layering order remains sane.

This is caused by glEnable(GL_POLYGON_SMOOTH);, disabling fixes

@Campbell Barton (campbellbarton) Thanks for finding that! Indeed, reading up on this, it seems to indeed be quite problematic.

A note for artists using Grease Pencil after this fix:
You'll need to enable Viewport Multisampling to avoid the jaggies which will now show up again on the edges of volumetric strokes and filled areas.