Conformal perspective as an option in TDM?

[Guest]

Even if we take the different way of measuring FOV for TDM, we can visually pinpoint values that feel more or less natural.

IMO, with FOV 70 things start to look like player is having a zoom lens, which makes for very claustrophobic and uneasy feeling. But even if I start from that, the amount of stretching is substantial.

FOV 70:

FOV 80:

FOV 90:

[Xolvix]

The only issue I have with upping the FOV in some games is that it can narrow the things in direct sight, which may or may not "cramp" the main areas of interest even if you are getting more peripheral imagery. Having said that, it seems like different engines can have different effects when high FOVs come into play. I have found that I need at least a 90 FOV (actual, horizontal 90 FOV) at a minimum before I'm happy, but even then I've noticed some games with an FOV of 90 seem fine while others feel like I'm too zoomed in.

For example, Deus Ex 1 has a default FOV of 75 intended for a 4:3 monitor. When running on 16:9 the various FOV calculators will suggest a new FOV of 90 to compensate, which is correct. But for some reason in Prey 2017, 90 FOV feels a little too claustrophobic whereas Deus Ex seems OK. What's more annoying is I didn't give a shit about running Prey with 90 FOV, but now that I'm aware of how FOV can differ, it's starting to annoy me! Ignorance really was bliss, so I upped it just a bit to 94 until that feeling went away.

[Xolvix]

Another trick I read somewhere - if you want to know whether a game's FOV is comparable with the FOV you expect, you can try this technique (only for first-person games):

(1) Set the game's FOV to 90
(2) Find two relatively long walls that join into a 90 degree corner and back yourself into the corner, facing out
(3) If the game is correctly using 90 horizontal FOV, you should only be able to have one of the walls on the screen at any given moment.

At a listed FOV of 90 in the menu, The Dark Mod fails the test which means it's not actually 90 degrees. I've also found that GZDoom, EDuke32, Quakespasm and Yamagi Quake II also have this "issue", except that their FOVs are either intended for a 4:3 base and scaled in the engine, or there's a config setting that auto-scales the FOV as intended for the new resolution. In most cases the "correct" FOV is 105 or 106, but not all games support such FOVs and often stretch too much, whereas these source ports seem to work fine.

[Guest]

Maybe TDM simply has a 4:3 ratio resized and stretched to avoid pillarboxing?

[nbohr1more]

I wonder if this new "FovoTec" thing:

https://www.pcgamer.com/first-person-shooters-have-been-getting-perspective-wrong-all-along/

is just a Conformal perspective design being sold as something new?

Anyone better than I at interpreting the study paper:

https://psyarxiv.com/7xack/

?

[lowenz]

You have good memory, nbohr!

[stgatilov]

I think this can be implemented as postprocessing shader which takes a part of traditional render and bends it to get conformal projection.

I.e. when conformat projection is enabled:

1. Find minimum FOV so that camera view contains the whole thing visible in conformal projection
2. Render everything with traditional camera and this larger FOV
3. During tonemap, compute texcoords to sample input from using some nontrivial formula

Of course, step 3 will stretch or bend the pixel-perfect render in pretty weird and non-uniform way, so perhaps it would look blurry by 1 pixel in the middle, perhaps it would have aliasing near boundaries.

But it will achieve the desired effect with very little intervention into rendering.

[lowenz]

What if we can add some sort of supersampling (and automatically disabling MSAA) before? With a clear disclaimer about performance hit/fall.

Or add FXAA/SMAA as a global option (in mutual exclusion with MSAA) as last step.

*Conformal Perspective option ON -> no MSAA + optional SSAA + frame correction + optional FXAA/SMAA

*Linear Perspective + optional MSAA or FXAA/SMAA (as now, just add FXAA/SMAA)

Edited April 8, 2023 by lowenz

[nbohr1more]

New video about this topic:

https://github.com/MMqd/godot-screenspace-projection

Looks like the author fixed the low resolution center pixels via FSR up-scaling.

[I.C.H.I.]

Quake 2 RTX on Steam has a bunch of different projection settings, after trying them all I hated how unnatural it feels. It may look good on the static screenshots but in motion the effect is way too weird for me and even nausea inducing.

[STiFU]

Wow, it sounded interesting on paper, but these curved "straight" lines of the panini projection make me dizzy. I'll stick with linear perspective and a proper viewing distance. 

[covert_caedes]

15 hours ago, STiFU said:

Wow, it sounded interesting on paper, but these curved "straight" lines of the panini projection make me dizzy. I'll stick with linear perspective and a proper viewing distance. 

Same TBH.

And I don't think perspective looks bad in TDM in general.

Yeah, the moon looks weird on those screenshots on the first page, but I think that's more of a problem with skyboxes and not so much with geometry in general?
Maybe skybox code could be improved, or maybe just the material settings, or maybe a portalsky with a moon model would look better?

But before seeing those screenshots I never even noticed that the moon looks stretched when it happens to be in an upper corner of the screen - I usually don't look that closely at the corners, especially if the only thing shown there is part of the skybox and nothing immediately important (like enemies or cameras)

 

So with panini the center of the screen, where you look at most of the time, looks bent/distorted (especially when moving), while with standard projection the screen edges (that you don't look at so much) are a bit stretched. I think the latter is the better tradeoff

[sullium]

I think the main reason TDM's distortion might seem like an issue is that the FOV number in the settings is "wrong" when playing in widescreen aspect ratio (as mentioned a few times above).

For instance, I play with TDM's FOV setting set to "80" which puts my actual FOV somewhere between 90 and 100 (I can stand in a corner and easily see both walls). But another player might see that the default setting is "90" and leave it there because it sounds right. They might then find that something seems off about the distortion, but fail to realize it's because the actual FOV is higher than they're used to.

Clarifying the setting's name and description in the menu seems like the least destructive solution to this. The name could be "Player FOV (Base)", "Player FOV (4:3)", or "Player FOV (Virtual)" to tip the player off that it's not quite what they expect. Then the description could end with "Automatically adjusted for aspect ratio (ie. 75 becomes ≈ 90 at 16:9)". From there, I guess the default should be changed to 75 as that puts the true FOV at a more "normal" value.

[Arcturus]

On 7/11/2018 at 5:30 AM, AluminumHaste said:

I think this is what you guys are talking about:

Looks pretty good at 50%.

[AluminumHaste]

On 2/5/2021 at 5:57 AM, Guest said:

Even if we take the different way of measuring FOV for TDM, we can visually pinpoint values that feel more or less natural.

IMO, with FOV 70 things start to look like player is having a zoom lens, which makes for very claustrophobic and uneasy feeling. But even if I start from that, the amount of stretching is substantial.

FOV 70:

FOV 80:

FOV 90:

 

LOL and here I am playing at 115-120 FOV on 16:9

[lowenz]

Of course there's the classic solution: play "straight perspective".....on a curved monitor screen 

It's why I always preferred '90s CRT to "flatron/FD trinitron"-like CRT and all the non-CRT monitors....

Today monitors are really designed for office/work needs.

Edited August 24 by lowenz