Crashes and issues while drawing with or without GPU acceleration

[Frozen Death Knight]

I don't know what exactly is triggering this, but while working in 1.9.1 I have noticed that the program occasionaly freezes and crashes when doing simple stuff such as drawing with the Brush Tool. Just now I had Photo do exactly that after having worked for a couple of minutes on a sketch which just didn't happen in 1.8.5. A single line drawn can crash the program even with GPU acceleration off.

However, this is a much more minor issue compared to when I have been trying to use GPU acceleration. I am reliably getting issues with it. Here are some of them that I can recall from this week:

1) The UI becoming unresponsive with the mouse cursor remaining like a Brush Tool cursor when trying to use the panels and menus, so you can't interact with anything.

2) Undo commands getting delayed for several seconds before anything happens.

3) Rendering artefacts on brush strokes. A brush stroke can create destructive eraser boxes around each stroke dot which delete anything that are below them, thus destroying anything on that specific layer.

4) Corrupted history states where the only thing that is getting saved is the stroke while the rest of the layer becomes completely blank. Only the stroke data gets saved when pressing undo, but anything else on said layer gets destroyed, and it happens to every single history state except for the latest history state for some reason.

5) Delayed brush strokes which are slower than when just using the old CPU method. This is noticeable when you attempt to draw multiple strokes in a row fast. They also seem to trigger some of the bugs on this list from time to time.

6) More freezes and eventual crashes.

I reported on a bunch of these problems back during the 1.9 Beta. Some of them I actually thought had been solved, but after having worked in Affinity for a longer period of time after the official release I can say with absolute certainty that all those old reports are as valid now as they were back then. If I sit down and work on something for at least a couple of hours or so I can pretty much guarantee that any of these bugs and issues can appear. However, there is no reliable way for me to properly trigger them since they can happen after just a few minutes or even hours into a project, thus feeling pretty random.

All I know is that there a some really serious issues with the feature on Windows and that something has to be done to fix them.

[Chris B]

Hey Frozen Death Knight,

I don't know if you're using the beta at all but there are so many stability fixes going in that potentially the majority of these issues are already fixed.

As you said, there's no reliable way of triggering the issues so they're going to be next to impossible tot fix unless they just get fixed in the wash.

[Frozen Death Knight]

On 3/5/2021 at 4:32 PM, Chris B said:

Hey Frozen Death Knight,

I don't know if you're using the beta at all but there are so many stability fixes going in that potentially the majority of these issues are already fixed.

As you said, there's no reliable way of triggering the issues so they're going to be next to impossible tot fix unless they just get fixed in the wash.

Hey!

Well, maybe some of them have, but from my experience of using the Beta I am still noticing issue 1, 2, and 5 on a regular basis. Number 5 especially is incredibly noticeable and is very, very easy to reproduce (what you see in the Beta part of the video is the actual speed of the same type of brush strokes I did in the latest official release, so yeah, very laggy). Here's a direct comparison that shows the differences in responsiveness with GPU acceleration on and off. Number 1 also happens very often in relation to 5 and can also be shown in the video. When I directly hover over the Layers panel the UI can't respond because it is still trying to process all the brush strokes I drew.

The only area where GPU acceleration performs better than by using only the CPU is when you are holding down a brush stroke for a longer period of time and when the brush strokes are absolutely massive. However, fast brush strokes are very common when drawing, and the lag happens even on very small brush sizes so something doesn't seem to be right here. Also, issue number 2 happens in relation to the unresponsive UI and high processing times of each fast brush stroke, so just pressing undo when issue 5 happens is more than enough to replicate this.

[Chris B]

I didn't realise it was that bad or there would be such a difference.

What driver is the GTX 980 using? If it's fully up to date, I'd turn off OpenCL for now and keep it off. Perhaps just test it now and then in every new beta to see if it has improved.

You aren't losing anything over 1.8.5 - you just aren't gaining the acceleration. I think this is a feature that will continue to have development and improvements.

[Frozen Death Knight]

On 3/8/2021 at 10:50 AM, Chris B said:

I didn't realise it was that bad or there would be such a difference.

What driver is the GTX 980 using? If it's fully up to date, I'd turn off OpenCL for now and keep it off. Perhaps just test it now and then in every new beta to see if it has improved.

You aren't losing anything over 1.8.5 - you just aren't gaining the acceleration. I think this is a feature that will continue to have development and improvements.

I am using version 461.40, so it isn't the very latest drivers (downloading it as we speak). However, I seriously doubt that it will solve all this lag considering my previous attempts at installing the latest ones both during the Beta and for the official release. Will still try, but I'll remain pessimistic as of now.

Yes, I agree that I can still go back to not using GPU acceleration, so I can fall back on having the old performance. Though, it is a bit unfortunate that things are working the way they do right now, especially when I was looking forward to having this feature available. Hopefully you over at Serif will be able to solve this lag issue with fast brush strokes, since I do think the feature should have room to grow and improve. Funnily enough, there actually is a significantly high performance boost on massive brushes, and the lag affects even the smallest of brushes, so there probably is some bottlenecking going on that affects every newly applied brush stroke which is not necessarily related to hardware. After all, there are bugs still left to uncover, so solving them might eventually lead to fixing the bottleneck. ^^