Building the pine
The world of Buildom was starting to look like a construction site. Dirt, stone, wood, caves, a zombie hand or two, but not a single plant anywhere. Time to change that. The first species is a pine tree, and getting it into the game taught me a lot about how the world is put together.
A tree is not a block
My first instinct was to treat a tree like terrain. Just stack wood blocks and call it a day. That fell apart quickly, because a tree behaves completely differently than a wall: you walk through it, chopping any part of it should give you wood, and the crown is one big sprite that spans multiple tiles.
So trees got their own system. A pine is composed of dedicated plant parts instead of terrain blocks: a root sitting on the surface, trunk tiles, optional branch stubs with a leaf mass on one side, and a top. The top is either the big multi-tile crown sprite or, on some trees, a single dead tip. Every part is non-solid, so the player walks straight through the trunk. Chopping any part drops wood, which keeps the interaction simple: a tree is a tree, no matter which tile you hit.
The whole thing is data-driven. The species itself is just a list of part tiles and sprites, so adding a birch or an oak later means adding entries, not rewriting the placement code.
Plant mode
Blocks already had a selection panel, so plants got one too. A new bag icon in the toolbar opens the plants panel, where clicking a species selects the whole tree for placement. Double-clicking opens a parts sub-panel instead, where every single tree part is placeable tile by tile.
One rule turned out to be more important than I expected: only one thing can be selected at a time, across all panels. Selecting a plant clears the block selection, selecting a part clears the species, and closing the parts panel hands the selection back to the whole tree. Without that, the game silently forgot what you were about to place.
Plant mode only exists in free mode, which brings me to the part I enjoyed most.
Free mode as a showroom
Free mode lets me place anything without inventory limits, and it turned out to be the perfect way to see the pine in every variation. Ten trees in a row, then single trunks, lone crowns floating in the air, a dead tip here, a branch poking out of a hillside there. When you can stamp down any combination in seconds, weird cases surface immediately instead of hiding until some player finds them weeks later.
The test world from that session is now a permanent fixture: a flat grass strip with ten pines planted by the real placement code, so every future change to the tree system gets compared against the same forest.
There is still plenty to do around trees. Growth, seeds, maybe falling trunks when you chop the wrong tile first. But the world finally has something green in it, and it feels a lot less like a digging sandbox and a lot more like a place. If you want to watch Buildom grow one system at a time, follow along.