Grid Size
BeginnerGrid Size controls the overall dimensions of your buildable space — the maximum extent your build can occupy. Changing it doesn't affect where your camera starts or which materials you can use, but it directly determines how large a structure you can create and what happens to existing blocks when you resize.
The Three Dimensions
Your build space is defined by three dimensions, each adjustable from 2 to 100:
| Dimension | Axis | What it controls |
|---|---|---|
| Width (X) | Left–right | How many cells wide the buildable area is. |
| Height (Y) | Up–down | How many layers tall the buildable area is. |
| Length (Z) | Front–back | How many cells deep the buildable area is. |
Each can be set using its slider or by typing a number directly into the field next to the slider. The sliders are fast for rough sizing; the number field is better when you want an exact value.
Committing with Resize
Adjusting the sliders or typing new numbers doesn't immediately change the grid — it's a preview of what the new size would be. You have to tap the Resize button to actually apply the changes. This lets you dial in all three dimensions before committing, without accidentally triggering a resize mid-adjustment.
If you change the numbers but decide you don't want to resize after all, simply navigate away or change the values back — nothing happens to your build until you hit Resize.
What Happens to Your Build When You Resize
The behaviour differs by axis, and it matters a lot when you're shrinking:
Width (X) and Length (Z)
Width and Length resize from the centre outward:
- Growing: Adds new empty cells evenly on both sides. Your existing build stays centred and untouched.
- Shrinking: Removes cells from both edges inward. Any blocks that fall outside the new boundary are permanently deleted. There is no undo for this — the deletion happens as part of the Resize commit.
Height (Y)
Height behaves differently and more safely:
- Growing upward (default): Adds new empty layers above your current top. Your existing build is completely unaffected.
- Shrinking downward: Reduces the maximum number of layers from the top. Blocks on layers above the new height limit are hidden by Blueprint Reveal, not deleted. Grow the grid back up and they reappear.
This means Height is "safe" to adjust — you can grow it and shrink it freely without losing anything permanently, unlike Width and Length which can cause irreversible deletion at the edges.
Y Axis Direction
By default, the grid grows upward when you increase Height — new layers appear above your current build. A direction toggle lets you change this so the grid grows downward instead:
| Setting | Effect when growing Height |
|---|---|
| Up (default) | New layers appear above the current top. Existing build is unchanged. |
| Down | New layers appear below the current build. The existing build shifts up to accommodate the new space underneath it. |
When growing downward, Buildopia asks what to do with the existing grass base layer at the bottom of your build:
- Maintain: The grass layer shifts upward with the rest of the build, staying at its current position relative to the build's floor.
- Drop: The grass layer is removed before shifting, and the new bottom layer is filled with fresh grass instead.
- Remove: The grass layer is stripped entirely and the new bottom is empty.
Growing downward is useful when you realise mid-build that you need a basement, underground level, or underwater foundation that sits below your existing structure.
Terrain Generator
Directly below the Resize button is the Terrain Generator — a tool that fills your grid with procedurally generated terrain in one tap. It handles biome style, terrain height, water (ocean and lakes), and optional caves. Each generation is unique.
Set your desired grid dimensions before opening the Terrain Generator — it will resize the grid to match when you generate. See the Terrain Generator guide for a full walkthrough of every option.