godot-performance-optimization

NEVER Do in Performance Optimization

• NEVER optimize without profiling first — "I think physics is slow" without data? Premature optimization. ALWAYS use Debug → Profiler (F3) to identify actual bottleneck [20].
• NEVER use print() in release builds — print() every frame = file I/O bottleneck + log spam. Use @warning_ignore or conditional if OS.is_debug_build(): [21].
• NEVER ignore VisibleOnScreenNotifier2D for off-screen entities — Enemies processing logic off-screen = wasted CPU. Disable set_process(false) when screen_exited [22].
• NEVER instantiate nodes in hot loops — for i in 1000: var bullet = Bullet.new() = 1000 allocations. Use object pools, reuse instances [23].
• NEVER use get_node() in _process() — Calling get_node("Player") 60x/sec = tree traversal spam. Cache in @onready var player := $Player [24].
• NEVER forget to batch draw calls — 1000 unique sprites = 1000 draw calls. Use TextureAtlas (sprite sheets) + MultiMesh for instanced rendering [25].
• NEVER block the main thread for heavy operations — Avoid OS.delay_msec() or long synchronous data processing. Use WorkerThreadPool to keep framerates steady.
• NEVER use complex collision shapes for physics queries — High-poly convex shapes are expensive to resolve. Prefer simplified primitives (Circle, Rectangle, Box).
• NEVER forget to disconnect local lambda signals — Anonymous lambdas connected to global signals can cause memory leaks if the capturing object is freed.
• NEVER use large textures without VRAM compression — VRAM is limited. Use S3TC/BPTC for desktop (DirectX/Vulkan) and ETC2 for mobile. Note: Disable compression for Pixel Art to avoid artifacts [13].
• NEVER perform tree modifications during physics steps — Adding/removing nodes during _inter_ray or _physics_process can lock the physics server. Use call_deferred.
• NEVER skip shader pre-warming in the Compatibility renderer — Unlike Forward+, OpenGL lacks Ubershaders. Pre-instantiate every mesh/VFX in front of the camera for 1 frame behind a loading screen to avoid hitches [21].

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Debug → Profiler (F3)

Tabs:

• Time: Function call times
• Memory: RAM usage
• Network: RPCs, bandwidth
• Physics: Collision checks

Profiler-Tab Decision Tree

Open Debug → Profiler first. MANDATORY load only the script for the hot tab/symptom.

Do NOT Load every perf script for a single hitch.

Profiler / symptom	Likely cause	Script
Time — same script hot	Alloc / get_node / process	object_pool_system.gd, cache @onready; custom_monitor_profiler.gd
Time — off-screen AI/VFX	Process while invisible	MANDATORY manual_culling_logic.gd
Memory — climbs over time	Leaks / unique resources	shared_resource_strategy.gd; pair with debugging orphan tools
Physics — collision spikes	Query/node RayCast spam	MANDATORY low_level_physics_query.gd
GPU / draw calls	Unique sprites/meshes	MANDATORY multimesh_optimizer.gd / multimesh_foliage_manager.gd / texture_array_batching.gd
SceneTree overhead at scale	Canvas/mesh item spam	MANDATORY rendering_server_direct.gd
Main-thread hitch (gen/parse)	Sync heavy work	MANDATORY worker_thread_pool_manager.gd
Crowd path spikes	Nav agents same frame	navigation_agent_optimization.gd
Custom game metrics	Missing monitors	custom_performance_monitor.gd

Available Scripts

object_pool_system.gd

MANDATORY for hot-path spawn/despawn — reuse, do not invent Array pop pools inline.

manual_culling_logic.gd

VisibilityNotifier-driven process disable for CPU-heavy off-screen entities.

rendering_server_direct.gd

RenderingServer canvas/mesh path when SceneTree overhead dominates.

low_level_physics_query.gd

Direct space-state queries vs hundreds of RayCast nodes.

worker_thread_pool_manager.gd

WorkerThreadPool offload for heavy jobs.

multimesh_optimizer.gd / multimesh_foliage_manager.gd

Hardware instancing for dense meshes/foliage.

texture_array_batching.gd

Texture2DArray batching to cut material switches.

shared_resource_strategy.gd

Shared vs local-to-scene memory tradeoffs.

navigation_agent_optimization.gd

Staggered path updates for crowds.

custom_monitor_profiler.gd / custom_performance_monitor.gd

Performance.get_monitor / custom monitors for game-specific spikes.

Expert Pointers (keep short)

• Compatibility renderer: pre-warm pipelines (hidden camera + unique meshes/materials one frame). Forward+/Mobile: Ubershaders still need instantiate-once detection.
• VRAM: S3TC/BPTC desktop, ETC2 mobile; skip compression for pixel art.
• AStar/path budgets belong in navigation_agent_optimization.gd — do not paste thrashy queue snippets as the golden path.

Deep dives (on demand)

• Path time-slicing, Compatibility shader pre-warm, VRAM codec table → profiler-budgets-and-prewarm.md

Reference

Progressive disclosure: open Official Documentation links only when researching a specific API; load Related Skills when routing to a peer domain — do not preload the whole lattice.

Official Documentation

• General optimization — profiler-first workflow so you measure Time/Memory/Physics before changing code.
• CPU optimization — process cost, node lookups, allocations, and why hot-path patterns dominate frame time.
• GPU optimization — draw calls, overdraw, and VRAM compression choices that cut render cost.
• Using MultiMesh — hardware instancing for thousands of meshes and why spatial splits restore culling.
• Using Servers and Resources — RenderingServer/PhysicsServer direct APIs when SceneTree overhead is the bottleneck.
• Using multiple threads — WorkerThreadPool task model for heavy work off the main thread.
• Thread-safe APIs — which engine APIs are safe from worker tasks versus SceneTree-only calls.
• Pipeline compilations — shader/pipeline hitch causes and pre-warm strategies per renderer.
• Optimizing 3D performance — LOD, cull distances, and mesh complexity budgets for 3D scenes.
• Occlusion culling — OccluderInstance3D tradeoffs when frustum culling alone is not enough.
• Performance — built-in monitors plus custom metrics for game-specific bottleneck dashboards.
• Optimizing Navigation Performance — agent update budgets and bake costs for large crowds.

Related Skills

Prerequisites

• godot-project-foundations — scene tree, resources, and import basics required before profiling or pooling patterns make sense.
• godot-gdscript-mastery — typed hot paths, callables, and @onready caching that keep optimization scripts correct.
• godot-resource-data-patterns — shared vs local-to-scene resource ownership that drives memory and unique-instance tradeoffs.

Complements

• godot-2d-physics — collision layers, queries, and body counts that show up as Physics profiler spikes.
• godot-physics-3d — 3D shape cost and RigidBody budgets when optimizing simulation-heavy scenes.
• godot-raycasting-queries — direct space-state query patterns that replace heavy RayCast node stacks.
• godot-shaders-basics — material/shader complexity and Texture2DArray batching that reduce GPU state changes.
• godot-scene-management — threaded loads and scene packing that prevent hitch spikes during streaming.
• godot-navigation-pathfinding — agent path budgets and async bake that pair with staggered AI updates.
• godot-3d-world-building — GridMap/LOD/occlusion level layout that sets the ceiling for draw-call budgets.

Downstream / consumers

• godot-adapt-desktop-to-mobile — resolution/shader fallbacks and battery modes that apply these budgets on weaker GPUs.
• godot-export-builds — export presets and renderer choices where compression and Compatibility pre-warm matter.
• godot-genre-open-world — chunk streaming and HLOD systems that consume MultiMesh, culling, and thread-pool patterns at scale.

Master

• godot-master — library router and mirrored module entry for cross-skill discovery.