render-sprite-vfx

name	render-sprite-vfx
description	Render monster sprites that require shader effects or particles (e.g. Waterfall Giant, Living Fog) by recreating the game's Godot scene with VFX in our Godot project.

Render VFX Monster Sprite

For monsters that can't be rendered with the standard /render-sprite skill because they use shader materials, GPU particles, or other Godot-specific VFX. This skill recreates the game's scene setup programmatically in GDScript.

When to Use

Use this when /render-sprite produces broken results due to:

• Placeholder textures (e.g. "Smoke Placeholder" watermark)
• Flat translucent rectangles instead of water/fog effects
• Missing particle effects that define the monster's appearance

Overview

The approach:

1. Extract the monster's .tscn scene file from the game PCK to understand what VFX nodes, shaders, and textures are used
2. Extract all referenced assets (shaders, textures, materials)
3. Write a custom GDScript that loads the Spine skeleton AND recreates the VFX nodes programmatically
4. Render interactively with slider + capture button

Step 1: Extract and Analyze the Scene File

"/c/Users/jparr/Downloads/GDRE_tools/gdre_tools.exe" --headless \
  "--recover=/d/Steam/steamapps/common/Slay the Spire 2/SlayTheSpire2.pck" \
  "--output=/c/Users/jparr/Documents/claude/sts2/raw" \
  "--include=res://scenes/creature_visuals/{monster_name}.tscn"

Read the .tscn and identify:

• SpineSlotNode entries with normal_material (shader materials applied to spine slots)
• SpineBoneNode entries (VFX attached to bones)
• GPUParticles2D nodes (particle effects)
• Sprite2D nodes with shader materials (fire, water effects)
• External resource references (shaders, textures, materials)
• The sprite's scale and position

Step 2: Extract Dependencies

Extract all referenced resources from the PCK:

• Shader files (.tres VisualShader or gdshader)
• Texture PNGs (smoke textures, gradient textures, particle sprites, fire textures)
• Material .tres files (for reference — we recreate these in GDScript)

Copy textures to spine_godot/assets/textures/ subdirectories. Copy shaders to spine_godot/assets/shaders/.

Important: Godot can't load raw PNGs via load() without importing them first. Use Image.load_from_file() + ImageTexture.create_from_image() instead:

func _load_tex(relative_path: String) -> ImageTexture:
    var img = Image.load_from_file(project_dir + "/" + relative_path)
    return ImageTexture.create_from_image(img)

Shader .tres files CAN be loaded via load() since they're Godot resources.

Step 3: Write the Render Script

Create a GDScript (e.g. render_{monster}.gd) that:

1. Loads the Spine skeleton from disk
2. Creates a SpineSprite with the correct scale from the scene file
3. Plays idle animation, paused (set_time_scale(0))
4. Creates ShaderMaterial instances in code, setting all shader_parameters from the scene file
5. Attaches materials to SpineSlotNodes or SpineBoneNodes by slot/bone name
6. Optionally adds GPUParticles2D nodes (skip flipbook particles that don't render correctly — these show as white blobs)
7. Adds interactive UI (CanvasLayer + VBoxContainer with slider and capture button)
8. On capture: clones everything into a 6144x6144 SubViewport, waits for particles to fill, screenshots, converts to webp

Key Patterns

Applying shader materials to Spine slots:

var slot_node = SpineSlotNode.new()
slot_node.slot_name = "body_water_rect"  # from the .tscn
slot_node.normal_material = my_shader_material
slot_node.show_behind_parent = true
sprite.add_child(slot_node)

Attaching VFX to a Spine bone:

var bone_node = SpineBoneNode.new()
bone_node.bone_name = "staff_fire_attach"
bone_node.show_behind_parent = true
sprite.add_child(bone_node)
# Then add Sprite2D or GPUParticles2D as children of the bone node

Creating shader materials from scene data:

var mat = ShaderMaterial.new()
mat.shader = load("res://assets/shaders/my_shader.tres")
mat.set_shader_parameter("Color", Color(0.33, 0.23, 0.30, 1))
mat.set_shader_parameter("ScrollSpeed", 0.22)
mat.set_shader_parameter("smokeTex", _load_tex("assets/textures/my_texture.png"))

Interactive UI must use CanvasLayer to render on top:

var canvas_layer = CanvasLayer.new()
add_child(canvas_layer)
var ui = VBoxContainer.new()
ui.set_anchors_preset(Control.PRESET_BOTTOM_WIDE)
ui.offset_top = -120
canvas_layer.add_child(ui)

Particles that use flipbook animation (CanvasItemMaterial with particles_anim_h_frames) won't render correctly with manually loaded textures — they show as white circles. Skip these; the monster usually looks fine without them.

Scene/Script Template

Each VFX monster gets:

• render_{monster}.gd — the GDScript
• render_{monster}.tscn — minimal scene that just loads the script

[gd_scene load_steps=2 format=3]
[ext_resource type="Script" path="res://render_{monster}.gd" id="1"]
[node name="Main" type="Node2D"]
script = ExtResource("1")

Launch with:

"C:/Users/jparr/Downloads/Godot_v4.6.1-stable_win64.exe/Godot_v4.6.1-stable_win64_console.exe" --path "C:/Users/jparr/Documents/claude/sts2/spine_godot" res://render_{monster}.tscn 2>&1

Already Created VFX Renderers

Monster	Script	Key VFX
Waterfall Giant	render_waterfall.gd	Water shader on body/mouth slots, mist particles, droplets
Living Fog	render_living_fog.gd	3-layer scrolling smoke shader on smoke_tex slots
The Lost / The Forgotten	render_lost_forgotten.gd	Scrolling smoke shader (shared script, use --monster= flag)
Entomancer	render_entomancer.gd	Bug swarm ring particles
Kin Priest	render_kin_priest.gd	Fire shader on staff bone + glow particles

Candidates for VFX Rendering

Monster	Folder	Expected VFX
Fogmog	fogmog	Likely similar smoke/gas shader
Cubex Construct	cubex_construct	2D sphere shader for the orb (body blocks still need --skin=moss2 --anim=attack_loop)

Paths

• Game PCK: D:/Steam/steamapps/common/Slay the Spire 2/SlayTheSpire2.pck
• GDRE tools: C:/Users/jparr/Downloads/GDRE_tools/gdre_tools.exe
• Godot exe: C:/Users/jparr/Downloads/Godot_v4.6.1-stable_win64.exe/Godot_v4.6.1-stable_win64_console.exe
• Godot project: C:/Users/jparr/Documents/claude/sts2/spine_godot/
• Extracted game files: C:/Users/jparr/Documents/claude/sts2/raw/
• Shader assets: spine_godot/assets/shaders/
• Texture assets: spine_godot/assets/textures/
• Final webp: C:/Users/jparr/Documents/claude/sts2/media/enemies/