Expert Godot shader patterns for batch-safe hitflash, alpha-scissor foliage/dissolve, screenspace postFX, depth reconstruction, triplanar, and instance uniforms — not first-shader tutorials. Trigger on draw-call batching breaks, discard vs depth-prepass, foliage shadows, post-process quads, or world

NEVER Do in Shaders NEVER use discard unconditionally for optimization — It prevents the depth prepass from working effectively. A discarded pixel still costs vertex processing; sometimes not rendering the object is better [1]. NEVER use if/else for dynamic states in high performance shaders — GPUs hate branching. Use mix() , step() , and smoothstep() for mathematical, hardware optimized selection [5, 21]. NEVER compare floats exactly — Hardware precision varies; if (v == 0.5) is unreliable. Use abs(a b) < epsilon or step() . NEVER use standard Alpha Blending for massive foliage — It prevents shadows and SSR. Use Alpha Scissor or Alpha Hash (dithering) to enable depth prepass and shadow casting [7]. NEVER hardcode POSITION to vec4(VERTEX, 1.0) for full screen quads in 4.3+ — Godot 4.3 uses Reversed Z depth; this will cause clipping. Use POSITION = vec4(VERTEX.xy, 1.0, 1.0) [8, 9]. NEVER duplicate materials to change one color/value on many enemies — Use instance uniform . This allows unique values for thousands of nodes while maintaining a single draw call (batching) [10]. NEVER use TIME without a speed multiplier — Fragment speed should be controllable via uniforms to ensure consistency across different gameplay states. NEVER forget hint source color for color uniforms — Without it, the engine treats colors as linear math, leading to incorrect gamma and washed out visuals in the inspector. NEVER calculate complex math in fragment() that could be in vertex() — vertex() runs once per point; fragment() runs millions of times per frame. Interpolate values via varying instead. NEVER use define macros for dynamic runtime toggles — These create new shader permutations, causing massive compilation stutters when first encountered in game. Use uniforms instead. NEVER forget to normalize vectors — Using reflect(dir, normal) on unnormalized vectors causes severe rendering artifacts and incorrect lighting math. NEVER modify UV without bounds checking or fract() — Shifting UVs beyond 0.0 1.0 without repeat wrapping or clamping will sample edge pixels or return black, breaking texture consistency. Scenario → Script Triggers MANDATORY for the matching effect. Do NOT Load beginner canvas item tint recipes or built in variable glossaries here. Goal Script Per enemy hitflash without breaking batches MANDATORY [instance uniform hitflash.gdshader](scripts/instance uniform hitflash.gdshader) Foliage wind + shadows MANDATORY [foliage wind sway expert.gdshader](scripts/foliage wind sway expert.gdshader) (alpha scissor/hash — not unconditional discard ) Dissolve that keeps depth prepass MANDATORY [dissolve scissor expert.gdshader](scripts/dissolve scissor expert.gdshader) PostFX pixelate / stylize MANDATORY [screenspace hex pixelate.gdshader](scripts/screenspace hex pixelate.gdshader) Full screen quad (Reversed Z) MANDATORY [screenspace full quad.gdshader](scripts/screenspace full quad.gdshader) Depth → world for water/fog MANDATORY [depth world reconstruction.gdshader](scripts/depth world reconstruction.gdshader) Grass flatten from player [global grass flatten.gdshader](scripts/global grass flatten.gdshader) UV less cliffs/rocks [triplanar world mapping.gdshader](scripts/triplanar world mapping.gdshader) Unique textures on instanced meshes [instance texture array.gdshader](scripts/instance texture array.gdshader) Vertex displacement terrain [noise terrain displacement.gdshader](scripts/noise terrain displacement.gdshader) Animate uniforms at runtime [shader parameter animator.gd](scripts/shader parameter animator.gd) VFX port template [vfx port shader.gdshader](scripts/vfx port shader.gdshader) Golden path for cutouts/dissolve: ALPHA SCISSOR / alpha hash (see dissolve + foliage scripts) — not discard for optimization. NEVER list explains why. Available Scripts [instance uniform hitflash.gdshader](scripts/instance uniform hitflash.gdshader) Instance uniform flashes; one material, many unique intensities. [dissolve scissor expert.gdshader](scripts/dissolve scissor expert.gdshader) Mask dissolve with ALPHA SCISSOR for depth prepass + shadows. [foliage wind sway expert.gdshader](scripts/foliage wind sway expert.gdshader) World space wind sway for foliage batches. [global grass flatten.gdshader](scripts/global grass flatten.gdshader) global uniform player interaction flattening grass. [screenspace hex pixelate.gdshader](scripts/screenspace hex pixelate.gdshader) hint screen texture stylized postFX. [screenspace full quad.gdshader](scripts/screenspace full quad.gdshader) Reversed Z safe full rect post pass. [depth world reconstruction.gdshader](scripts/depth world reconstruction.gdshader) hint depth texture → world position. [triplanar world mapping.gdshader](scripts/triplanar world mapping.gdshader) World axis projection without UVs. [instance texture array.gdshader](scripts/instance texture array.gdshader) sampler2DArray + instance uniform for unique batched textures. [noise terrain displacement.gdshader](scripts/noise terrain displacement.gdshader) Vertex noise displacement. [vfx port shader.gdshader](scripts/vfx port shader.gdshader) Validated VFX shader template. [shader parameter animator.gd](scripts/shader parameter animator.gd) Tween/runtime uniform animation without AnimationPlayer. [shader warmup loader.gd](scripts/shader warmup loader.gd) Pre warm shader pipelines during loading screens to avoid first frame stutter. Expert Pointers Move invariant math to vertex() ; pass via varying . Color uniforms need hint source color . Prefer Official Docs for shading language builtins; this skill owns batching, scissor, screenspace, and depth routing. Deep recipes (on demand) LLM ignorance rule: if a general agent would not know it before reading, it lives here or in scripts/ — never delete, only move. Topic Reference 2D dissolve/wave/outline [2d effect recipes.md](references/2d effect recipes.md) 3D toon + vignette [3d and postfx recipes.md](references/3d and postfx recipes.md) Uniforms / built ins [uniforms and builtins.md](references/uniforms and builtins.md) Fog, compute, warmup [expert advanced patterns.md](references/expert advanced patterns.md) Reference Progressive disclosure: open Official Documentation links only when researching a specific API; load Related Skills when routing work to a peer domain — do not preload the whole lattice. Official Documentation [Introduction to shaders](https://docs.godotengine.org/en/stable/tutorials/shaders/introduction to shaders.html) — Entry map of shader types, render modes, and when to use ShaderMaterial vs StandardMaterial3D. [Shading language](https://docs.godotengine.org/en/stable/tutorials/shaders/shader reference/shading language.html) — Core GLSL like syntax: uniforms, hints, varyings, built ins, and preprocessor rules used throughout this skill. [CanvasItem shaders](https://docs.godotengine.org/en/stable/tutorials/shaders/shader reference/canvas item shader.html) — 2D canvas item built ins ( UV , COLOR , TEXTURE , SCREEN UV ) for sprites, UI, and 2D post FX. [Spatial shaders](https://docs.godotengine.org/en/stable/tutorials/shaders/shader reference/spatial shader.html) — 3D spatial built ins ( ALBEDO , NORMAL , instance uniform , depth/screen textures) for materials and full screen quads. [Your first 2D shader](https://docs.godotengine.org/en/stable/tutorials/shaders/your first shader/your first 2d shader.html) — Minimal canvas item workflow from ShaderMaterial attach through fragment tinting. [Your first 3D shader](https://docs.godotengine.org/en/stable/tutorials/shaders/your first shader/your first 3d shader.html) — Minimal spatial workflow and conversion path from StandardMaterial3D into writable shaders. [ShaderMaterial](https://docs.godotengine.org/en/stable/classes/class shadermaterial.html) — Runtime set shader parameter / instance parameter API used by animators and hit flash batching. [Custom post processing](https://docs.godotengine.org/en/stable/tutorials/shaders/custom postprocessing.html) — Screen reading shaders, hint screen texture , and compositing patterns for pixelate/vignette style FX. [Advanced post processing](https://docs.godotengine.org/en/stable/tutorials/shaders/advanced postprocessing.html) — Depth buffer, reversed Z, and world reconstruction needed for water/fog/debug visualizers. [Compute shaders](https://docs.godotengine.org/en/stable/tutorials/shaders/compute shaders.html) — RenderingDevice GPGPU path for particle sims and other non fragment workloads. [Using VisualShaders](https://docs.godotengine.org/en/stable/tutorials/shaders/visual shaders.html) — Graph editor + VisualShaderNodeCustom extensibility covered in the expert patterns. [GPU optimization](https://docs.godotengine.org/en/stable/tutorials/performance/gpu optimization.html) — Overdraw, transparency, and batching guidance that motivates alpha scissor, instance uniforms, and vertex vs fragment cost. Related Skills Prerequisites [godot project foundations](https://github.com/thedivergentai/gd agentic skills/blob/main/skills/godot project foundations/SKILL.md) — Nodes, Resources, and project layout required before attaching ShaderMaterials and shipping .gdshader assets. [godot resource data patterns](https://github.com/thedivergentai/gd agentic skills/blob/main/skills/godot resource data patterns/SKILL.md) — Sharing vs duplicating ShaderMaterial/Shader Resources so uniforms and instance parameters stay batch friendly. Complements [godot 3d materials](https://github.com/thedivergentai/gd agentic skills/blob/main/skills/godot 3d materials/SKILL.md) — StandardMaterial3D/ORM first; graduate to spatial shaders for triplanar, dissolve, and instance uniform effects. [godot 3d lighting](https://github.com/thedivergentai/gd agentic skills/blob/main/skills/godot 3d lighting/SKILL.md) — How custom ALBEDO / EMISSION / light() output interacts with Forward+, GI, and fog volumes. [godot particles](https://github.com/thedivergentai/gd agentic skills/blob/main/skills/godot particles/SKILL.md) — Particle process/draw materials and alpha pipelines that must match scissor/hash vs blend choices from this skill. [godot 2d animation](https://github.com/thedivergentai/gd agentic skills/blob/main/skills/godot 2d animation/SKILL.md) — CanvasItem shader hooks for stylized 2D motion, outline, and dissolve on animated sprites. [godot camera systems](https://github.com/thedivergentai/gd agentic skills/blob/main/skills/godot camera systems/SKILL.md) — Camera near/far and view/projection matrices that screen space and depth reconstruction shaders depend on. [godot performance optimization](https://github.com/thedivergentai/gd agentic skills/blob/main/skills/godot performance optimization/SKILL.md) — Draw call batching, MultiMesh, and GPU budgets that justify instance uniform and avoiding unique materials. [godot debugging profiling](https://github.com/thedivergentai/gd agentic skills/blob/main/skills/godot debugging profiling/SKILL.md) — GPU/overdraw profilers and debug views to validate shader cost and depth/normal visualizers. Downstream / consumers [godot procedural generation](https://github.com/thedivergentai/gd agentic skills/blob/main/skills/godot procedural generation/SKILL.md) — Procedural meshes/terrain consume noise displacement, triplanar, and UV less spatial patterns from this skill. [godot 3d world building](https://github.com/thedivergentai/gd agentic skills/blob/main/skills/godot 3d world building/SKILL.md) — Large environment props apply foliage wind, grass flatten, and world projection shaders at level scale. [godot genre open world](https://github.com/thedivergentai/gd agentic

godot-shaders-basics