World and levels › Large worlds
Open-world budget
Know first: Open world: how it loads in pieces, The frame budget on the graphics card
One screen of numbers and checks for an open world: the size of the ground, the cells and the loading range, the density of vegetation and the draw distance. It also gives the frame budget and the memory budget, what to look at in the profiler, and what to check before you expand the world. The numbers come from the lessons of the course “Your own open world”, and the links lead to where each one comes from. Click a boxed value to copy it.
Ground
| What | Number | Why |
|---|---|---|
| Grid step of a landscape | 1 m by default (scale 100 on X and Y) | The narrowest ditch is two steps wide. grid step |
| Ready-made sizes | 2017 vertices → 2.0 km; 4033 → 4.0 km; 8129 → 8.1 km | Sections of 63 or 127 quads, components of 2 × 2 sections. where the numbers come from |
| Halving the step | four times as many vertices | On 4 × 4 km of ground, a 1 m step gives 16 million vertices and a 0.5 m step gives 64 million. cost of the step |
| Components and sections | at most 1024 components (32 × 32); a section is 63 quads (127 for 8129 vertices) | Epic advises this. Each section is its own draw call. components |
| Heights | 16 bits = 65,536 height levels; at Z scale 100: range 512 m, one level ≈ 0.78 cm | A larger Z scale stretches the same levels. Z scale |