How we grew a forest without buying a single tree

Every tree in Mythfell's forest used to be a cone on a stick. Forty-four triangles, honest about what they were, and the whole game looked like a prototype because of it.

The normal fix for that is money: buy a SpeedTree license, or download photogrammetry scans. We tried the second road for rocks and logs — real scanned boulders do ship in the game — but for trees it's a dead end at our scale: a single scanned tree can be more geometry than our entire rest-of-forest combined, and it arrives with a license and a cleanup project attached.

So we wrote a tree generator instead. And somewhere in the middle of it, we learned the thing that this whole post is really about:

A tree doesn't look real because of its polygon count. It looks real because of its branch structure and its leaves.

The generator builds a tree the way you'd expect — a trunk that tapers, branches that sprout from branches, each generation thinner, shorter, and reaching more sideways, with noise so no two trees match. That part is the easy half. Our first result had all of that and still looked wrong: like a green fist on a stick. A "cabbage," as we started calling it.

Two changes did more than any amount of extra geometry:

1. We stopped putting the leaves where the branches end. The first version hung every leaf card at the tip of its branch — so each branch ended in one flat clump, and clumps read as objects, not foliage. Real canopies are layered: some leaves ride the outer branch tips, some sit inboard and smaller, and the volume between them is what your eye reads as a tree. We made every other leaf card sit inside the canopy at a different size, and the cabbage was gone.

2. We stopped lighting every leaf the same. Our leaf texture was a generated cluster — and an evenly-bright cluster reads as one solid blob from a top-down camera, no matter how detailed it is. So each leaf card now gets its own random brightness, from 60% to 118%. Half the "depth" people see in our canopies is just... some leaves are in shade. That's it. That's the trick.

The whole forest — two tree variants, each with three detail levels that swap in as you zoom out — costs 2,516 triangles at full detail and 140 at the far distance. The 29 trees around the first battlefield, plus everything behind them, are all this one generator with different seeds. Zero purchased assets, zero license paperwork, and every tree is unique because we asked for unique.

One last honest note, because it caught us twice: we verified all of this by rendering test images, not by looking at the editor viewport. That habit found two bugs a glance would have waved through — vertex colors that rendered pure white because no material referenced them, and branches that were all vertical tubes because a rotation was applied to the branch's cross-section instead of its length. If a picture renders wrong, it is wrong, even if the numbers look fine.

The forest in the screenshot above is what shipped. Cones on sticks are gone, and nobody will ever notice — which is exactly the point.

Next devlog: what our first real players taught us — two dozen installs, five countries, and five cents of revenue.