@Julien Kaspar (JulienKaspar) Could you prepare a simple file with these corner cases to use for doing some test? I'm thinking to prepare a simplify using the distance between points, and I would like to have a file for testing.

@Antonio Vazquez (antoniov) @Matias Mendiola (mendio) @Daniel Lara (Pepeland) (pepeland)
I agree. The optimal drawing feel should be most important. The suggestion of the even spacing of points will feel worse and will make details get lost with to wide spacing but in certain corner cases can have a curve that's easier to work with. The simplify & adaptive simplify are great additions but don't solve the problem of massively uneven spacing or extremely dense curves.
The spacing option could also be used for drawing regular poly curves. I hope that these will share a lot of functionality with grease pencil at some point since grease pencil is so much more advanced now.

Yes, keeping accuracy of the final strokes is so so important. drawing with acurracy is the key for a good workflow in 2D tasks, like @Matias Mendiola (mendio) said, more than 80% of the time used by the artist with Grease pencil is freehand drawing,
for this reason we create a group of functions in grease pencil brushes to improve the the drawing accuracy.

Thanks @Antonio Vazquez (antoniov) for the clear explanation. I agree with you that the main risk with this change is to lose the pleasant feeling that we have right now while drawing with Grease Pencil (more than 80% of the time used by the artist with Grease pencil is freehand drawing).

Regarding this task, there are several points we must consider.

@Antonio Vazquez (antoniov) the issue was with freehand drawing.

@Campbell Barton (campbellbarton) You are talking of free drawing an stroke or darwing a curve using primitive tool? it's not clear what you mean with "draw a curve", maybe you mean draw a "stroke".

@Charlie Jolly (charlie) Could you take a look?

Actually I can crash x64 (edc1b0167518-windows64) with a file created in blender-2.80.0-git.e2102e991764-windows32 without ...\Blender\2.80\config\startup.blend and 2D animation template:

So this fix goes in the right direction, but it's not complete. All the sound handles and state should only exist and get updated on the evaluated scene, not the original scene. That means saving audio and playback should also get data from the evaluated scene.

I added an audio track in the sequencer to do some testing. Everything seams to work fine. Only when adding another track while rendering, the added track is part of the remaining render. But this seems to be a general problem, as moving the cube in the default scene while rendering does show up in the render too. I assume this is limited to animation rendering.

The two calls to BKE_sound_update_scene both come from a depencygraph. One holds the copies for the viewport and the other one for the renderer. Both are running in their own thread. BKE_scene_graph_update_tagged happens to not be called for the render thread. But BKE_scene_graph_update_for_newframe is called for both, which is a problem.

Nice find on where the problem was introduced! I'd be fine with the temporary fix. Are you sure that this doesn't prevent both calls of the two threads during rendering? One should still be done. I'm not sure what moving to the dependency graph will change here, does the dependency graph get updated from two threads as well? Or is it two different instances and thus as you said viewport and renderer each need their own sound_scene instance?

The problem seams to have been introduced in 48f9e24f0c1e Enable dependency graph update while rendering.

Unless the grease pencil team thinks this is important issue to solve, I'd rather not add this additional complexity to the code.

It just feels weird, having a brush setting that allows you to change the active object material but not its own material.

This is not a bug. The Hide operator of Grease Pencil is by layer, not by points of strokes. When you press H, you are hiding the whole layer. You can check this in the layers panel (the eye icon changed).

I'm going to reasign to @Campbell Barton (campbellbarton) because it looks a more general topbar issue.

This crash is a different issue. The object not visible is due a different reason...I'm thinking how to fix it.

Possibly related. Blender crashes if I then do the following:

Also, change uiTemplateList is something that can affect whole Blender UI, so you need the opinion of @Brecht Van Lommel (brecht), and maybe @Bastien Montagne (mont29) . Not sure it worth change this template only for this small UI problem... really, the user only need unpin ansd select new material, not a big deal.

I'm still not a big fan of using different formats for Material list when pinned, and this patch uses different UI layouts.

@Campbell Barton (campbellbarton) @William Reynish (billreynish) I have seen a problem with topbar (the same I have in grease pencil) for other objects.

Well I think that's it. I can't get it to crash anymore.
So are the template files going to have to get updated, as opening 2D Animation still crashes 32-bit?

Ahh... yes, the template files bundled with Blender would have the 'bad dna'.

yeah but you mentioned opening, files created with 'bad dna' are gonna have bad dna, but is the issue still there when you create a new file in a recent version?

@Brecht Van Lommel (brecht) beat you to it :) T61413#653490

up until last week, there was an issue in blenders DNA code for 32 bit, fields were not the size blender though they were, can you still reproduce the issue in files created in a recent build?

After more investigation it looks like you can't open blend files (with GPencil data) on different architectures than what it was made on.

The problem is the when delete an object, must back to Object mode as it's done with meshes.