Customizing Block Highlights

Changing a Block's Selection Box

Highlight Mod lets you draw more complex visual selection boxes than vanilla Minecraft allows. This is purely a client-side effect: it changes what you see, not where you can actually hit. The real block hitbox stays the same, so the block must still be reachable within its normal hitbox for the highlight to matter.

There are two ways to attach a highlight to a block. Mod authors can implement the Highlightable interface directly on their block through code. Alternatively, anyone can use the JSON API, which is useful for non-mod-authors who want to change a hitbox to match a new block model.

Highlights are client assets, so their JSON files live in your assets folder under the namespace resourcefullib/highlights. A highlight JSON represents a single highlight state, similar to how a block has a blockstate file and a model file. Each highlight contains a list of lines, and each line is an array of six floats: the first three describe the first point, and the remaining three describe the second.