Does 30 fps look too uncanny for a retro style game?

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spaceharrier
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Does 30 fps look too uncanny for a retro style game?

Post by spaceharrier »

In my WIP engine, I am doing a lot of heavy things, including handling 32 actors in a scene, depth sorting, keeping off-camera actors busy, pixel-perfect collision detection, 4 way scrolling, dynamic front-back priority for hiding behind overhead objects.

I have about half the tools and code finished. I am quite sure I will blow available single frame cycles, even with keeping things tight.

From experience, would results look too jarring or uncanny if I went to 30 fps? Are there other notable 30 fps games, other than TMNT, I could use to gauge?
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gauauu
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Re: Does 30 fps look too uncanny for a retro style game?

Post by gauauu »

I would think the best answer is "it depends on how things move, you'd probably just have to try it and see".

My guess is that if things generally move slowly, then it would be fine. But if it's a fast-paced game where things are moving rapidly (multiple pixels every one of your double-frames) then it's going to start looking bad.
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Ben Boldt
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Re: Does 30 fps look too uncanny for a retro style game?

Post by Ben Boldt »

Is it possible for your program to become aware of dropped frames and throttle back dynamically? Then you could have a dynamic framerate that could even drop multiple frames at a time if necessary. Not sure I have ever seen this done on an NES. Everything would have to be coded such that it could advance N frames instead of always assuming it is advancing 1 frame, and I am sure that costs a lot of overhead to do something like that.
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Dwedit
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Re: Does 30 fps look too uncanny for a retro style game?

Post by Dwedit »

Wizards and Warriors 3 cheated, running the game at 30FPS but interpolating the player's coordinates and the camera at 60FPS.
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rainwarrior
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Re: Does 30 fps look too uncanny for a retro style game?

Post by rainwarrior »

spaceharrier wrote: Wed Sep 21, 2022 1:30 pmAre there other notable 30 fps games, other than TMNT, I could use to gauge?
30fps was the most common framerate target through the whole 360/PS3 era. 60fps was an exception. (On earlier generations in the 3D era it was often even less.)

I think there are quite a few games on NES that operate at 30 or 20 fps, though I don't have a list offhand. Solar Jetman and Solstice are two I remember that haven't been mentioned.
Ben Boldt wrote: Wed Sep 21, 2022 1:58 pmIs it possible for your program to become aware of dropped frames and throttle back dynamically?
It's quite easy to count frames via the NMI. Finding a way to update dynamically is harder. The easiest thing is just to skip rendering and do the simulation/physics twice, but that probably only buys back 25% of a frame at most. It's a lot easier on modern stuff where it's reasonable to multiply a floating point time delta by everything... though doing that results in less deterministic behaviour than a fixed timestep.
GValiente
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Re: Does 30 fps look too uncanny for a retro style game?

Post by GValiente »

Dwedit wrote: Wed Sep 21, 2022 2:54 pm Wizards and Warriors 3 cheated, running the game at 30FPS but interpolating the player's coordinates and the camera at 60FPS.
That cheat is great, I've used it in the past and I guess lots of games have used it without people noticing.

For example, you can do collision detection with half of the objects in odd frames and with the other half in even frames.

If you split your most CPU intensive tasks in half, it's like running the game at 30FPS but showing it at 60FPS.
The same concept can be applied with sprite animation, for example.
calima
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Re: Does 30 fps look too uncanny for a retro style game?

Post by calima »

It's totally fine to run at 30fps as long as it's stable. So no "sometimes 60, occasional drops to 30" - if you can't do 60, have the fast frames sleep so they are 30fps.
Oziphantom
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Re: Does 30 fps look too uncanny for a retro style game?

Post by Oziphantom »

rainwarrior wrote: Wed Sep 21, 2022 5:22 pm 30fps was the most common framerate target through the whole 360/PS3 era. 60fps was an exception. (On earlier generations in the 3D era it was often even less.)
And the PS2 and the PS1 era ;)
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tokumaru
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Re: Does 30 fps look too uncanny for a retro style game?

Post by tokumaru »

Oziphantom wrote: Thu Sep 22, 2022 1:29 amAnd the PS2 and the PS1 era ;)
Aren't many games on the Switch, a very successful and current-gen console, also 30fps?

I don't think that 30fps games on 8 and 16-bit systems are particularly bad. If it's well made, fun, and the frame rate doesn't hurt the controls, I'd rather have a game running steadily at 30fps than constantly switching back and forth.

With limited hardware, something's gotta give... you're not gonna be able to make incredibly complex games with perfectly smooth 60Hz animation in a short period of development. Optimization takes time, and there are cases where even with the highest levels of optimization, the hardware is simply maxed out.
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Re: Does 30 fps look too uncanny for a retro style game?

Post by Oziphantom »

star fox, stunt racer SFX ran at what 12~15fps and they sold millions.
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tokumaru
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Re: Does 30 fps look too uncanny for a retro style game?

Post by tokumaru »

Oziphantom wrote: Thu Sep 22, 2022 5:41 amstar fox, stunt racer SFX ran at what 12~15fps and they sold millions.
They had a pretty good excuse for that though, which was plain to see. If a game isn't doing much out of the ordinary, or if it is but that isn't obvious to players, then a lower frame rate won't be as easily excusable.
Oziphantom
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Re: Does 30 fps look too uncanny for a retro style game?

Post by Oziphantom »

if it has a solid reason then sure, if its just poor programming then no.
spaceharrier
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Re: Does 30 fps look too uncanny for a retro style game?

Post by spaceharrier »

I really like the interpolation idea. It doesn't seem to cycle intensive to do so, spare some extra memory for storing a few deltas.

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Fiskbit
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Re: Does 30 fps look too uncanny for a retro style game?

Post by Fiskbit »

30 FPS games feel noticeably less smooth than 60 FPS games. They're still fine, and a stable framerate is worth a lot, but almost every game on the NES is 60 FPS and so it's definitely noticeable when you play one that runs slower. That's not necessarily a problem, and being able to do more at a lower framerate can be a good tradeoff, but I'd still aim for 60 if it's possible to do with what you have in mind.
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Re: Does 30 fps look too uncanny for a retro style game?

Post by TmEE »

I'm not fond of 30fps for anything that scrolls, there are double image artifacts that come from it which make things look blurry when motion begins (it stems from eyes tracking motion and the doubled image blending in with new stuff, but I'm not fully sure about the mechanism), it doesn't look particularly smooth anymore. This also is a problem with 100/120Hz frame doubling CRT TVs that were popular in Europe, I managed to work in a "black frame insertion" method into the signal path on mine and that made games look fine again, at cost of dimmer image.

If half rate can be avoided it should be, at least for scrolling games. WIth 3D things it isn't as offensive though it is clearly visible when image is turning and in edges of the screen when moving forward as motion is biggest in there but center stays good. Modern variable refresh rate displays are able to fix this problem to a great degree.
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