Performance Settings - "Dither Gradients" and "Use Precise Clipping"

[Ldina]

Below are my "View Quality" Settings in Affinity Apps. I usually work in 16 bits (always with RAW images), but sometimes I work in 8 bit, when the file is only available as an 8-bit file. (I can convert to 16 bit if required for operations that require it.)

What exactly do the settings, Dither Gradients and Use Precise Clipping do? Presumably, they ONLY affect the rendering of the file data to the monitor and don't alter data in the file.

What are the benefits/liabilities of turning these two settings ON or OFF?

I do know that Dither Gradients turns a Posterized gradient into a blurry mess. Does this only affect gradients created with the Gradient Tool?Turning Dither Gradients OFF, results in sharp demarcation between posterized steps, which is what I'd expect (and normally want). What if it is left OFF by default? Any issues?

I'm not even sure what Use Precise Clipping does or when it is invoked.

Any clarification would be appreciated. Thanks.

[loukash]

28 minutes ago, Ldina said:

I'm not even sure what Use Precise Clipping does or when it is invoked.

Searching the forum for "Use Precise Clipping" (incl. quotes) will return, among others, this result:

I haven't read it in full, but looks to me that by describing the accompanying bug(s), the thread also explains what this setting does.

Perhaps the same luck with "Dither Gradients", I guess…? 

[NotMyFault]

Dither gradients affects viewing in app primarily, but:

• if directly affects gradients on pixel layers
• it affects results of merge operations (rasterizing) 
• It affects layer fx gradients
• Must test again, but probably affects transparency tool (in v1)

At export, gradients are always getting dithered. For that reason, I recommend to let it on/activated.

If you deactivate it, enjoy a smooth (non dithered) gradient, you may get unpleasant surprise after exporting.

My way to deal is to have one parent layer (Artboard, group, …) and add layer FX color overlay at 0%. Eliminates dithering reliably, and inherits down to all child layers. And works both inside app and for export.

If required you can adjust anti-aliasing (off) when working pixel art and fonts.

[NotMyFault]

Precise clipping should be activated. The performance impact is neglectable in most cases, and you avoid certain artifacts when clipping layers. 

[Ldina]

15 minutes ago, NotMyFault said:

At export, gradients are always getting dithered. For that reason, I recommend to let it on/activated.

I just tried it, and you are exactly right. Dithering needs to stay ON most of the time to avoid surprises on export. Your suggestion to use FX Color Overlay at 0% opacity works great and solves the ugly posterized gradient dithering, both with screen rendering AND exporting. Thank you!

13 minutes ago, NotMyFault said:

Precise clipping should be activated. The performance impact is neglectable in most cases, and you avoid certain artifacts when clipping layers. 

Thanks, I'll toggle it ON.

I'm still not sure what "Use Precise Clipping" actually does though. It would be nice to have more information on what it does and when, both for myself and others who stumble onto this discussion.

Thanks for the great help, as always. 😃

 

[Pšenda]

2 hours ago, Ldina said:

I'm still not sure what "Use Precise Clipping" actually does though.

For your interest:

[Ldina]

21 minutes ago, Pšenda said:

For your interest:

Thanks, @Pšenda. It will take some time for me to digest that discussion, but I will look and play. 👍