Static Objects & Batching
Marking scenery Static tells Awaken3D an object never moves, which lets the renderer merge many objects into a single draw call and gives physics a simpler, fixed body. This page explains what the flag does and when to use it.
The Static flag
Static is an entity-level flag (not a component): it's either on or off for a whole object. Set it from the Inspector or the Hierarchy's right-click menu, on one object or a whole multi-selection at once. It's an undoable edit, and it's saved in the scene (an object is only written as static: true when the flag is on).
The flag is a promise: this object's transform will not change at runtime. Two systems act on that promise.
📸 Screenshot - save as img/world-static-flag.png
The Inspector header of a selected building with the Static checkbox ticked, and the stats overlay showing the "Static … merged" count.
What marking Static does
1. Render batching (index-merge)
Drawing thousands of separate scenery meshes is expensive - each is a draw call. Static batching collapses many of them into a few.
Awaken3D uses an index-merge scheme. Static meshes that share a texture and sit in the same spatial cell are concatenated into one merged mesh and drawn together. Crucially, world transforms are not baked into the merged geometry: every vertex keeps its object's local position and carries an objIndex that selects that object's matrix from a stable per-object transform buffer in the shader.
Objects are bucketed by spatial cell so frustum culling still works at chunk granularity - a chunk of scenery off-screen is culled as a unit. Opaque and alpha-blended statics go into separate chunks so blending still sorts correctly.
Two kinds of static object are kept off the merge and drawn per-object instead: one with a MeshMaterial (its custom shader can't run through the material-blind static pipeline), and one with shadow casting turned off. Everything else static falls back to per-object drawing once the Batch threshold or merge budget is reached.
2. A fixed physics body
For physics, a static object with a collider becomes a fixed body - immovable world geometry that other bodies collide against but that never itself responds to forces. This is exactly what you want for floors, walls, and terrain.
Repeated meshes stay instanced
Not everything should merge. A mesh used many times (a fence post placed 500 times) is already efficient to draw with GPU instancing - one upload, many transforms. Merging those would duplicate the geometry hundreds of times and blow up memory.
So batching only merges low-repeat static meshes. A mesh is merged only if its use count is at or below the Batch threshold; heavily-repeated meshes are left instanced. The result: unique scenery merges into a few draws, and repeated scenery stays instanced.
Moving a static object is cheap
The "static" promise is about the common case, not a hard lock. Because the merge keeps per-object transforms in a separate buffer, moving a static object is a single transform-slot write - no re-merge, no geometry rebuild. Only adding, removing, or moving an object across a cell boundary rebuilds the affected chunk. In practice you can nudge static scenery in the editor freely; you just shouldn't animate it every frame from a script (use a non-static object for that).
Settings
Static batching is tuned in Render Settings:
| Setting | Default | Range | What it controls |
|---|---|---|---|
| Static batching | on | on/off | Master toggle for merging static scenery. |
| Batch threshold | ≤ 8 uses | 1–32 | Only meshes used at most this many times are merged; more-repeated meshes stay instanced. |
| Merge budget | 8M verts | 4–32M | How much geometry to merge into chunks before falling back to per-object draws. Raise on heavy scenes to cut draw calls; costs merged-geometry GPU memory. |
Watch the Draw calls and Static … merged figures in the Viewport stats overlay while you tune these - the goal is fewer draw calls without exhausting memory.
📸 Screenshot - save as img/world-render-settings-batching.png
The Render Settings panel showing the Static batching toggle, Batch threshold slider, and Merge budget slider.
When to use it
- Do mark non-moving scenery: buildings, walls, floors, terrain decoration, static props - especially many unique small meshes that share a texture.
- Don't mark objects that move under script or physics each frame (doors, platforms, characters, pickups that spin) - keep those non-static so the renderer treats them as dynamic.
See also
- Rendering performance - draw-call budgets, instancing, and the full perf picture.
- Transforms & Hierarchy - the moved-set that makes moving a static object cheap.
- Render Settings - where the batching sliders live.
- Colliders - how a static collider becomes a fixed body.