Note: This guide was made in reference to “Double Helix version 2.0”
This section contains information about Double Helix's (seemingly) most basic function, level editing. This pertains to changing the physical layout of rooms, like adding/removing walls, platforms, lava/acid, missile/super missile/power bomb/energy tanks, etc.
Rooms are made up of several layers, which have different properties.
Clipdata controls how Samus interacts with each block. Clipdata 10, “Block,” is a block that is solid on all sides. A “fall through” block crumbles when Samus touches the top. Samus can pass through “Air”/“No Block” freely.
Clipdata is independent of the Image layer, so you can assign a “Missile tank” clipdata to a blank tile, resulting in an invisible missile tank.
Double Helix has a sprite editing feature, reached through the menu: Tools>Sprite Editor. It has two main functions, modifying enemy palettes, and modifying Enemy Graphics.