Page 2 of 3

Re: 4d

Posted: Wed Sep 25, 2013 4:49 am
by raidho36
xXxMoNkEyMaNxXx wrote:I find my program a great deal more interesting to look at than that :P

I found that I do have similar rotations in my program by using the numpad keys 1-6, so it's not entirely wrong.
Well, you do have your rotation math correct, but visualizaiton is obviously goes apeshit almost instantly. It instead should look like those rotating tesseracts.
xXxMoNkEyMaNxXx wrote:I thought of the idea. My thinking: "Why not represent animated 3D meshes as 4D meshes?" Then I argued with myself about whether or not the triangle defined by six events in spacetime was ambiguous in 4D. I did make it a little while ago now, but its trippiness must have some significance.
Oh, I see. The problem here is that while time could be considered a dimension, it's not a spartial dimension and cannot be treaten as such. "In eucledan space, any axis is indistinguishable from any other axis". Speaking of that, many "4d" games have a problem with that, like you can't rotate your view into 4th dimension, so it's always stands out, as in "extra" dimension rather than "yet another" dimension. If you turn around freely in 3d space, you eventually lose track of which way is up. Just the same way, in 4d space you should lose track of which way is up, it could be where your 4th dimension was initially whereas 4th dimension would be your left, etc.

[]

Posted: Wed Sep 25, 2013 10:47 am
by bekey
-snip-

Re: 4d

Posted: Wed Sep 25, 2013 11:11 am
by raidho36
Good question.

I'm not making the "true" 4d projection for my game, because it's just doesn't plays well: if you project it to 3d and then view it then it's just plain weird because 4th axis infinity would be at the center of the projection cube rather than actually at infinity as one would expect; further w-axis objects are 3d-shrinked and translated towards the projection cube center. If you project it to 2d bypassing the "viewing 3d projection of 4d space" thing, then you end up with 4th axis being perpendecular to your depth axis (camera sight axis) so therefore it can't contribute to the depth, and it's also perpendecular to X and Y so it can't contribute to objects' coordinates on the screen, ultimately giving zero contribution at all, so you'd have to use other means of depicting 4d "depth". Regardless, I went with the latter method. Although in this projection 4th axis does not contributes to the picture directly, I would use it to indirectly signify about objects' position along 4th axis, by altering objects' appearance.

[]

Posted: Wed Sep 25, 2013 2:14 pm
by bekey
-snip-

Re: 4d

Posted: Thu Sep 26, 2013 6:45 am
by raidho36
Kinda like that.

Re: 4d

Posted: Fri Oct 04, 2013 3:57 pm
by Ref
Please excuse my profound ignorance - don't have a clue as to what 4D really is.
Ran across this and was wondering if this was in any way related to 4D (not mine - I only converted it to Love)???

Re: 4d

Posted: Fri Oct 04, 2013 4:13 pm
by kikito
There have been other previous forays in 4d in gaming. I remember one 4d ship shooter. Don't remember its name though.

I think the guys who did it previously decided that modeling the four dimensions "realistically" (with space distorsions etc when the objects rotated) made the experience completely unplayable for everyone.

At the end what they did was something "lighter". Your ship was a regular 3d-ship. Enemy ships too. You could move in 3d, like in a regular 3d game. Then you had 2 controls for moving "up" and "down" on the fourth dimension. When you moved this way, you would gradually see different objects that existed on other coordinates of the 4th dimension gradually - they would fade in and out. But they would nave no "rotational distorsion".

Pieces of the scenery (debris and nebulae) would appear and disappear .. and so would enemy ships and their shots. There were some points where you could see an object but your shots would go through it. Essentially, the fourth dimension worked like Asteroid's "hyperspace", but in a continuous way. It was fun.

Re: 4d

Posted: Fri Oct 04, 2013 4:51 pm
by raidho36
Ref wrote:Please excuse my profound ignorance - don't have a clue as to what 4D really is.
Ran across this and was wondering if this was in any way related to 4D (not mine - I only converted it to Love)???
Yes it is. This is in fact the single most common 4d demo - a rotating tesseract, the 4d "cube" (as in regular cube is a 3d "rectangle"), though the effects ruin the picture pretty bad. Although being the most notorious demo, a rotating tesseract doesn't really gives any feel of 4d. But you can see a bit of 4d there if you try really hard, by thinking that smaller shapes are being further away from you by 4th axis so it's a perspective distortion, because they're all the same size.
I remember one 4d ship shooter. Don't remember its name though.
Adanaxis? It isn't exactly 4d, it's more like regular 3d space shooter with an extra degree of dodging. Could've as well been just multicolor shields where only the same color bullets can penetrate it.
I think the guys who did it previously decided that modeling the four dimensions "realistically" (with space distorsions etc when the objects rotated) made the experience completely unplayable for everyone.
Maybe. In my game, I keep the 4th dimension as a spartial dimension, and not only you can move around it, you can also turn your view into it, and even though it doesn't contribute to the "3d" picture, you can directly see distance between you and 4d object. Note that because of mentioned eariler turning your view into 4th dimension, the one becomes one of the basic three, and one of the basic three becomes your 4th dimension, so you would experience sort of 4d perspective distortion.

Re: 4d

Posted: Thu Oct 17, 2013 12:47 am
by Garbeld
raidho36 wrote:
I remember one 4d ship shooter. Don't remember its name though.
Adanaxis? It isn't exactly 4d, it's more like regular 3d space shooter with an extra degree of dodging. Could've as well been just multicolor shields where only the same color bullets can penetrate it.
I don't get it. How is "an extra degree of dodging" not "exactly 4d"?
It might be a particularly boring fourth dimension in which one's heading is fixed and there are no terrain features (I'm not familiar with Adanaxis, so I'm referring to your example) - but the same could be said of the second dimension in a majority of sh'm'ups, which could certainly be recoded to draw everything at a fixed position along one axis and instead pass the now-unused position data into a color filter; mathematically speaking, they would be no different.

Re: 4d

Posted: Thu Oct 17, 2013 2:28 am
by raidho36
Following the shields idea, if I make shields consist of 3 color sliders, so you'd have to navigate along all 3 color components separately, rather than just hue slider, would this make up for a 6d game? No, obvioiusly. It's still a 3d game.