Game VFX: Mesh + Texture + Engine Math
Core Philosophy
3D 软件造壳，AI/贴图画皮，引擎赋魂。
VFX ≈ 简单 Mesh（塑料外壳）× 滚动贴图（活涂装）× 引擎数学（缩放/旋转/淡出/错开）
Do not render finished FX in DCC or rely on TyFlow/Houdini for indie iteration.
Do not replace textures with pure procedural noise2d() unless prototyping.
Standard Pipeline
| Step | Input | Output |
|---|---|---|
| 1. Mesh | CC0 VFX pack or Godot primitives (Plane/Cylinder/Torus) | UV-ready shell |
| 2. Texture | AI seamless noise or CC0 sprite sheet (Kenney placeholder) | Alpha/mask + detail |
| 3. Shader | sampler2D + UV scroll + style grade |
Visible texture shape |
| 4. Code | Tween scale / rotation / intensity / stagger | Timed performance |
| 5. Anchor | Node under Player at feet (y≈0) or chest | Correct bind point |
AI Texture Prompt Hints
Generate seamless, high-contrast masks suitable for UV scroll:
seamless jade ink wash noise, high contrast alpha, tileable, 512x512, no backgroundseamless magic energy noise, soft core bright edges dark, tileable- Avoid illustrative single-frame art; need tileable mask/energy maps.
Drop into assets/textures/vfx/ and assign to albedo_texture in shader.
Composition: 点 · 线 · 面
| Element | Role | Mesh | Texture examples |
|---|---|---|---|
| 面 | Base area, 60% main color | Horizontal plane, large billboard | circle, smoke, magic |
| 线 | Direction, trail, ink stroke | Thin billboard, ground trace plane | slash, trace, scratch |
| 点 | Accent sparkle, scatter | Small billboards | star, spark |
Layer with staggered delays (0.05–0.18s). Never spawn everything at t=0.
Color: 631 Rule + Contrast
| Share | Role | Usage |
|---|---|---|
| 60% | Main attribute color | Pool, rings, body aura |
| 30% | Secondary (adjacent hue) | Mist, inner glow, edge wash |
| 10% | Accent (warm/high sat) | Gold stars, white core flash |
Ink black (墨痕) is not part of 631 area — use as contrast edge (like bubble black rims): small coverage, high opacity.
Extended formula (fluid/magic):
主色冷色大面积 + 辅色邻近/弱对比 + 微面积色散高光 + 极小面积点缀色
For ink-wash projects: main = jade/teal; secondary = blue-purple mist; accent = warm gold; ink = near-black.
2.5D / Fixed Camera Rules (Critical)
Orthographic oblique camera (e.g. offset (20, 22.5, 20)) breaks many free-3D assumptions.
| Do | Don't |
|---|---|
Horizontal PlaneMesh for ground FX |
Vertical ring only visible as line |
Billboard planes for body FX (look_at camera) |
Cylinder/Torus body (shows caps, hides UV) |
Texture discard on low alpha (if mask < 0.025: discard) |
Uniform green fog without texture shape |
| Texture drives mask; shader tints | Procedural ring mask *= ring covering texture |
blend_mix + ink grade for main layers |
Full-scene neon blend_add |
blend_add only for accent/core layer |
|
Anchor ground at y ≈ -0.93 (feet), slightly above ground plane |
Same Y as ground (z-fight) |
Billboard facing (Godot 4):
node.look_at(camera.global_position, Vector3.UP)
node.rotate_object_local(Vector3.RIGHT, -PI * 0.5)
node.rotate_object_local(Vector3.FORWARD, yaw_offset)
Godot Implementation Pattern
Shader Split (3 materials max)
| Shader | Render | Purpose |
|---|---|---|
heal_vfx_layer.gdshader |
blend_mix |
Main layers: 4-tone grade, UV scroll, optional expand |
heal_vfx_ink.gdshader |
blend_mix |
Black ink strokes/splashes |
heal_vfx_add.gdshader |
blend_add |
Gold/white accent only |
Key uniforms: albedo_texture, scroll_speed, effect_time, intensity, expand_progress, tone_dark/mid/bright/accent.
Script Structure (heal_mesh_effect.gd reference)
HealEffect (Node3D, y=1.0 on Player)
├── Ground: pool + rings (horizontal planes)
├── Body: twirl billboards ×2 crossed yaw
├── Mist: secondary billboard (30%)
├── Ink: splashes, strokes, traces, rising flecks
└── Accent: core add + star billboards (10%)
API: trigger_heal() with cooldown; _process updates effect_time + billboard facing.
Tween Rules
# CORRECT — lambda passes float to intensity
_tween.tween_method(func(v): mat.set_shader_parameter("intensity", v), 0.0, 2.0, 0.3)
# WRONG — bind appends args; float hits wrong parameter
_tween.tween_method(_set_intensity.bind(mat), 0.0, 2.0, 0.3) # breaks in GDScript 4
Return type for tween_method: MethodTweener, not Tween.
Typed arrays for texture pick:
const SPARK_TEX: Array[Texture2D] = [TEX_A, TEX_B, TEX_C]
var tex: Texture2D = SPARK_TEX[i % 3]
New Skill Checklist
Before shipping a VFX, verify:
- Texture visible in isolation (not hidden by procedural mask / fresnel kill)
- Body elements face camera in 2.5D
- 631 color balance readable on project background
- Ink/contrast layer present if style is ink-wash
- Staggered layer timing
-
preload()textures; synceffect_timeon all materials - No dependency on sky/SDFGI/volumetric fog for this project style
- Headless load / in-game Q test passes
Anti-Patterns (Learned in game02)
| Failed approach | Why |
|---|---|
| GPUParticles + Kenney without billboard | Side-on quads invisible in 2.5D |
| Cylinder aura | Top cap reads as geometry, not texture |
| Pure noise shaders | No craft; flat green fog |
| Procedural ring × texture | Texture shape lost |
| Stacking 10+ layers same hue | Monotone, no 631 |
Tween.bind() for multi-arg setters |
Runtime type errors |
Reference Implementation (game02)
| Asset | Path |
|---|---|
| Effect script | scripts/heal_mesh_effect.gd |
| Layer shader | shaders/heal_vfx_layer.gdshader |
| Ink shader | shaders/heal_vfx_ink.gdshader |
| Add shader | shaders/heal_vfx_add.gdshader |
| Textures (placeholder) | addons/kenney_particle_pack/ |
| Scene hook | Player/HealEffect in scenes/main_3d.tscn |
Kenney mapping for heal: smoke_06 pool, circle_05 ring, twirl_02 body, light_03 halo, magic_02 mist, magic_04 core, star/spark accent, scratch/scorch/slash/trace ink.
For extended pitfalls and environment constraints, see reference.md.