AuthorTopic: Pixel art Skybox in 3D  (Read 5386 times)

Offline Seiseki

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Pixel art Skybox in 3D

on: February 12, 2015, 07:55:58 pm
I don't have much experience with Skyboxes, I know the very basics about how they work.
I know that to use a photograph for a Skybox you do some Photoshop wizardry to compensate for the distortion in the edges.

But I want to use low res pixel art for a Skybox, so I'm trying to figure out an alternative.
Right now I'm messing around with a SkyCylinder, because I thought I'd minimize the distortion if I used more faces.
I also don't need a top or bottom, so I think a cylinder will work.

I'm just posting to see if anyone with more experience has any tips.

Offline surt

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Re: Pixel art Skybox in 3D

Reply #1 on: February 12, 2015, 08:54:27 pm
I'd say you definitely don't want a skybox if you're using pixel art. The texel distortion at edges/corners will look horrible without sufficient resolution to hide it.

I'd go with something like was used in Doom or Magic Carpet: a flat texture that scrolls horizontally as you rotate around the vertical axis and scrolls vertically as you rotate around the horizontal axis. Pretty much the same result as a cylinder but with out edge distortion.

Offline Seiseki

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Re: Pixel art Skybox in 3D

Reply #2 on: February 12, 2015, 09:40:27 pm
Having no perspective looks weird in a 3D environment though..
I feel like I need to strike a good balance between distorted pixels and distorted perspective..
« Last Edit: February 12, 2015, 10:01:02 pm by Seiseki »

Offline surt

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Re: Pixel art Skybox in 3D

Reply #3 on: February 12, 2015, 09:43:56 pm
You draw the perspective in the texture same as with a skybox.

Offline Seiseki

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Re: Pixel art Skybox in 3D

Reply #4 on: February 13, 2015, 12:53:34 am
I should have mentioned it's a space background, sorry..
And I'm rotating the skybox camera constantly to simulate orbit. So it's kinda specific.

I think the sky in Magic Carpet sky works really well, but I don't think it will look as good in space and in widescreen.
The black space hides most pixel distortion and it looks natural when the stars flicker, but once I add nebulae it might look much worse.

I played some Doom and I'm not sure what they're doing with the skybox, but it has some weird distortion.

Offline tocky

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Re: Pixel art Skybox in 3D

Reply #5 on: February 13, 2015, 01:12:22 am
if you can map a texture to a sphere or a cylinder and get it to work, try that. platonic solids also good

Offline RAV

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Re: Pixel art Skybox in 3D

Reply #6 on: February 13, 2015, 05:00:23 am
Consider thinking about the skybox not as one single entity, but several separate entities together creating one impression.
Like different sprites, clean pixeling on simple billbox, orchestrated around, facing the player; overlaps, layers, experiment.
Especially for a space scenario this can work fairly well, even together with some code automatically placing sprites around.

Offline tocky

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Re: Pixel art Skybox in 3D

Reply #7 on: February 13, 2015, 10:46:22 am
what RAV is describing is not so much a one thing as a particle system is the idea of a bunch of ideas that fit together. but really (or so it seems to me)  its just him giving me shit for no reason. Particle systems are useful but they're shit to all to do with the question. I will talk to u you about skyboxes i have known. you can see that i am being real because the shit i tell you is useful and not just a bunch of nonsense. cylinders is the usual way to go, spheres is better, but avoid more arbitrary shapes (cubes are the worst, everything at 90 degrees means more points you can look at where the sky comes to a point . it's easy enough to do a cylinder instead )

platonic solids are good because they are the same shape on all sides. easy uv map to make.

RAV, it you're not just making fun of me, then using a particle system is good too. make a starfield. the sky doesnt need to be static. but i need not provide evidence for each post i make. i'm a professional, and u can trust me, i got my bs in videogameology. i am a bachelor of games
« Last Edit: February 13, 2015, 10:58:39 am by tocky »

Offline rikfuzz

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Re: Pixel art Skybox in 3D

Reply #8 on: February 13, 2015, 07:33:53 pm
I think Surt is right - Doom method definitely sounds like it's most suited.  Has no distortion (in the original version, at least not sure about source ports).

Combined with RAV's idea of layering, could work very well for space.  Rather than distorting the pixel art, can have some individual sprites on top for debris/planets/asteroids with individual positions based on imaginary 3d position but still drawn flat.  (So they'll still move faster near the edges but without getting skewed).

Think you're gonna have to experiment, but sounds like the way to go for pixel art to me.

Offline ptoing

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Re: Pixel art Skybox in 3D

Reply #9 on: February 13, 2015, 10:53:03 pm
The Skyboxes in Doom do have some distortion towards the side of the screen where they get stretched a bit. Nothing massive, but yeah, it is there. And I think if you are using FOV then this always will happen to a certain amount, unless you do more complex skyboxes.

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