[APh] Painfully slow mask layer painting in higher-res documents

[Alex_M]

I've noticed that Affinity Photo seems to be painfully sluggish when painting inside isolated mask layers (after ALT+clicking on them) of documents equal to or larger than 7-8 megapixels even when there is just 1 empty pixel layer with a mask. Painting in the mask layers without ALT+clicking on them is buttery smooth (real time), though. Why is that? On the same PC Photoshop is buttery smooth (real time) even when painting inside isolated (ALT+clicked) mask layers of 72 megapixel documents. This is a real problem for me since I do a lot of masking in documents that most of the time are a lot larger than 8 megapixels.

[Dan C]

Hi Alex_M,

I've tried to replicate this issue but I am not having the same results with any image other than with a rather ridiculous 38400 x 21600 (829MP) which due to it's size is to be expected.
Could you please provide a screen capture of the slow response from the software, and a copy of the .afphoto file? This way we can log the issue directly with our developers.

[Alex_M]

Sure, please follow this download link for the screen capture and the aphoto file (link expires in 7 days): https://we.tl/3xYtxvomd7

Let me know if you need anything else that could help pinpoint the problem. BTW, I installed the newest display drivers for my GPU and it's still as slow.

[Dan C]

Thanks for that Alex_M,
I have tried to replicate your issue, using both your file and by creating a new one, please see my video attached: 
Mask Painting.mp4
 

Although the preview for when painting on a mask can occasionally be slow, the painting of the mask itself is not sluggish as in your video and therefore I'm currently unable to provide an exact reason behind the issue. I will continue to investigate this internally however it may be due to an external process running on your computer at the time, it may be worth trying this from a clean boot of Windows to see if the problem persist.
https://support.microsoft.com/en-gb/help/929135/how-to-perform-a-clean-boot-in-windows

[Alex_M]

Thanks for the reply, Dan. I tried your suggestion but it didn't make any difference. What made a difference though was uninstalling Photo and installing the newest version - 1.6.4.104. Maybe something was broken in version 1.6.2.97 that I have been using. I can now edit masks in real time even in 100 Mpix documents! None of that choppy stuff. Wohoo! 

[Dan C]

I'm glad to hear you have it sorted Alex_M, my apologies as I should have checked earlier you were running the latest update!