Paraemon's Comprehensive Ripping Project Thread [Expansion Station]

[Paraemon]

All the excitement of seeing all the layers of parallax.

My bad, I should clarify this better.   

In Sonic 3 and Sonic & Knuckles, there are various effects throughout the stages that alter (parts of) the background depending on what's relevant to that stage, which affects the parallax. This is at its most simplistic in the Mushroom Hill Zone, as moving to a certain point of Act 2 changes the color of the background.

Angel Island and Launch Base (Act 2) Zones employ an underwater ripple/motion effect. Strangely, this happens for a few pixels above the water in Angel Island, too, which, when combined with the Heat Haze effect in Act 2, makes for a much more complicated animated sequence (oh god what have I let myself in for).

Heat Haze only effects four sections of the entire game: Angel Island (Acts 1-B and 2), Sandopolis (Act 1) and Lava Reef (Act 2-B ). As Sandopolis has been noted to be 32 frames of animation on a cycle and 1 frame to account for the default appearance without the effect, I can surmise that it is a similar figure in frames for the other sections in the game. Lava Reef's boss arena is a struggle on account of the fact of the screen-locked auto-scrolling feature, and Angel Island involves different palettes during the Heat Haze motions, as well as the overlap with the underwater effect.

Hydrocity (Act 1), Ice Cap and Launch Base (Act 2) Zones all employ a form of 2.5D effects on the water. While the first and the third of these stages evoke the feeling of parallax based on the movements you make, be it up and down or left and right, Ice Cap's 2.5D is the auto-scrolling ice floes. You can zip zoom left and right across the map, it's going to move of it's own accord, the only true parallax motion coming from the more distant glaciers.

Now that I've mentioned auto-scrolling in the background, I can name the stages that employ it: Angel Island (Act 1-A), Marble Garden (both acts), Ice Cap (Act 1-B and 2), Launch Base (Act 2), Flying Battery (both acts), Sky Sanctuary (both acts) and the Doomsday Zone. Even the Sonic & Knuckles Credits (and arguably, the Intro to Sonic 3) has this. What this entails, motion-wise, is that the cloud objects (which is what is typically in motion unless it's the ice floes) keep moving regardless of if you're idle or in motion in those stages - if idle, they carry on as normal, if in motion towards the right, it hastens the appearance of the cloud shapes, and if to the left, delays the encroaching shapes. To digress, this is seen earlier in the franchise, in Sonic 2's Hill Top Zone, but that operates on a speedier basis compared to S3K. Then we compare that with the background to Oil Ocean Zone, where the clouds do not in fact auto-scroll, but instead act as a functioning layer of the parallax.

It should be noted, Flying Battery and Sky Sanctuary's cloud object auto-scrollers also rise and sink on a timed basis, yet another function.

This now comes around full circle to the functions of the parallax, but we already know how that works, so let's cover a bit else. Stages like Hydrocity (Act 2) and Sandopolis (Act 1) display two layers of background: the pillars overlap the arches in the former, and the pyramid overlaps the distant dunes in the latter. Whilst it is simpler to extract the background of Hydrocity, the palette and Heat Haze effect in Sandopolis constantly fuse the Pyramid to the dunes, meaning there are very small windows to accurately identify the differential between each layer.

Elsehow, simplistic funtions like glow/color-shifting in the background (for example, Angel Island (both acts), Carnival Night (both acts), Ice Cap (Acts 1 and 2-cavern), Glowing Spheres) do not effect the parallax of a given stage, they're just there for aesthetics. The only backgrounds I've found thus far not to have any sort of parallax or otherwise cloud object auto-scrolling are in the Death Egg Zone (both acts).