Render Resolution Setting Question

[alanalot]

I have the option to render a game at 75% resolution but I don't know if it would be 75% of the total pixels or 75% of my resolution's pixels?

Because (3440 * 1440) * .75 = 3,715,200 pixels

But (3440 * .75) * (1440 * .75) = 2,786,400 pixels

[Eigenvektor]

I would expect it to be the second option. But it's up to the developer to decide which way they go with this.

 

The first one is needlessly complicated (for you as well as the engine). The engine needs to set the horizontal and vertical resolution. So it would have to do X * Y * .75, then use the resulting number of pixels and calculate the X and Y resolution for that using the monitor's aspect ratio.

[WereCat]

I remember Warzone had a bug and it kept changing my render resolution to 50% after I started the game. It also reported the output resolution to be 1280x720 and I have 2560x1440 monitor which means it actually halved my resolution by 50% on X and by 50% on Y axis so I assume the 2nd option is correct.

 

(2560 x 1440) x 0.5 = 1,843,200

(2560 x 0.5) x (1440 x 0.5) = 1280 x 720 = 921,600

[Eigenvektor]

5 minutes ago, WereCat said:

I remember Warzone had a bug and it kept changing my render resolution to 50% after I started the game. It also reported the output resolution to be 1280x720 and I have 2560x1440 monitor which means it actually halved my resolution by 50% on X and by 50% on Y axis so I assume the 2nd option is correct.

While it's technically incorrect it's much easier for a user to do the math in their head. Strictly speaking 1280 x 720 has 25% the number of pixels of 2560 x 1440 (.5 x .5 = .25)

 

If you scale the "area" by 50% instead, you'll end up with a resolution of 1810 x 1018 (math below)

Spoiler

To scale the actual resolution, the math is a bit more complicated:

new_width  = width  * sqrt(scale)
new_height = height * sqrt(scale)

 

So for example for 2560 x 1440 at 50% scaling it would be

2560 * sqrt(.5) = 1810.193…
1440 * sqrt(.5) = 1018.233…

 

So you end up with non-integer numbers. 1810 x 1018 is a bit less than the targeted 50%. However, if you use .25 you should see that you end up with the expected 1280 x 720.

 

If you scale the individual dimensions, you'll often end up with "well known" resolutions

1440p @ 75% = 1920 x 1080
1440p @ 50% = 1280 x  720
1440p @ 25% =  640 x  360

 

If you scale the "area" instead you*ll end up with weird (non-integer) resolutions in many cases

2560 x 1440 * .75 = 2217 x 1247
2560 x 1440 * .5  = 1810 x 1018
2560 x 1440 * .25 = 1280 x  720

[WereCat]

21 minutes ago, Eigenvektor said:

While it's technically incorrect it's much easier for a user to do the math in their head. Strictly speaking 1280 x 720 has 25% the number of pixels of 2560 x 1440 (.5 x .5 = .25)

 

If you scale the "area" by 50% instead, you'll end up with a resolution of 1810 x 1018 (math below)

  Reveal hidden contents

To scale the actual resolution, the math is a bit more complicated:

new_width  = width  * sqrt(scale)
new_height = height * sqrt(scale)

 

So for example for 2560 x 1440 at 50% scaling it would be

2560 * sqrt(.5) = 1810.193…
1440 * sqrt(.5) = 1018.233…

 

So you end up with non-integer numbers. 1810 x 1018 is a bit less than the targeted 50%. However, if you use .25 you should see that you end up with the expected 1280 x 720.

 

If you scale the individual dimensions, you'll often end up with "well known" resolutions

1440p @ 75% = 1920 x 1080
1440p @ 50% = 1280 x  720
1440p @ 25% =  640 x  360

 

If you scale the "area" instead you*ll end up with weird (non-integer) resolutions in many cases

2560 x 1440 * .75 = 2217 x 1247
2560 x 1440 * .5  = 1810 x 1018
2560 x 1440 * .25 = 1280 x  720

Well, QHD is Quad High Definition which is 2560x1440 and HD is 1280x720 so 4xHD = QHD like 4xFHD=UHD or "4k" not really much to count there.

[alanalot]

Here's three comparison shots.

1st is at full 3440x1440

2nd is 3d rendered 75% of 3440x1440 (which should be 2580x1080)

3rd is 2580x1080 upscaled to 3440x1440

[Awpiii]

https://www.omnicalculator.com/other/resolution-scale Here you go

3440x1440 at 75% render resolution is 2979 x 1247.

Math for the calculation is explained next to the calculator