GrowthShader
This shader is a Godot spatial shader that uses a growth texture (UV2 channel) to drive vertex animations and material blending, creating effects such as growth, expansion, or edge dissolution.
Core Mechanism
Vertex Stage
-
A noise texture is sampled to displace vertices along the normal direction, creating a continuous fluctuating motion.
-
The growth texture (UV2) is sampled to control vertex offset and scaling. When the growth value falls below the threshold
0.03, the vertex is shifted in a specified direction and scaled down. The offset and shrink intensity increase as the growth value decreases (i.e., the smaller the growth value, the stronger the offset and the more the vertex shrinks). This simulates a natural retraction or folding effect at the growth boundary.
Fragment Stage
-
Noise is blended with the growth value using world‑space coordinates (XZ plane) and time to add organic randomness.
-
If the blended growth value is below
0.3, it is further reduced. When it drops below0.01, the fragment is discarded, creating a dissolving edge. -
The material transitions between an emissive “growing” state and a final albedo state. The blend occurs when the growth value is between
0.3and0.4– albedo and emission are linearly interpolated, and the emission intensity fades simultaneously. -
The shader also supports normal mapping, roughness mapping, and optional alpha transparency.
Parameter Descriptions
| Parameter | Type | Range / Hint | Description |
|---|---|---|---|
grow_texture |
sampler2D |
— | Growth map sampled with UV2; red channel controls vertex offset/scaling and material blending. |
albedo_texture |
sampler2D |
— | Base color texture (RGB). |
normal_texture |
sampler2D |
— | Normal map (RGB). |
ems_texture |
sampler2D |
— | Emissive texture (RGB). |
noise_texture |
sampler2D |
— | Noise texture used in fragment stage to add randomness to growth. |
rounghess_texture |
sampler2D |
— | Roughness map (R channel). |
ems |
float |
— | Global emissive intensity multiplier. |
distortionVertex |
float |
0.0 – 0.3 |
Amplitude of vertex noise displacement along normal. |
speedVertex |
float |
0.0 – 1.0 |
Speed of vertex noise animation. |
noiseVertex |
sampler2D |
— | Noise texture for vertex displacement (UV‑based). |
offset_direction |
vec3 |
— | Direction (X, Y, Z) in which vertices are shifted when growth is low. |
offset_strength |
float |
— | Strength of the directional offset applied to low‑growth vertices. |
shrink_strength |
float |
— | Strength of the scaling applied to low‑growth vertices (1 = no shrink, lower values = more shrink). |
add_texture |
sampler2D |
— | Additional texture multiplied with albedo (e.g., detail color). |
add_ems_texture |
sampler2D |
— | Additional texture multiplied with emissive. |
alpha_apply |
bool |
— | If true, uses the alpha channel of albedo_texture for transparency. |
Use Cases
-
Growing plants, leaves, or branches
-
Magical energy spread or erosion effects
-
Gradual appearance or disappearance of objects
-
Dynamic visibility and material transitions for visual effects
The shader is highly customizable via its exposed parameters, making it suitable for a wide range of dynamic visual effects.
Shader code
shader_type spatial;
render_mode cull_back;
uniform sampler2D grow_texture;
uniform sampler2D albedo_texture;
uniform sampler2D normal_texture;
uniform sampler2D ems_texture;
uniform sampler2D noise_texture;
uniform sampler2D rounghess_texture;
uniform float ems;
uniform float distortionVertex : hint_range(0.0, 0.3, 0.005) = 0.03;
uniform float speedVertex : hint_range(0.0, 1.0, 0.005) = 0.5;
uniform sampler2D noiseVertex;
uniform vec3 offset_direction = vec3(1.0, 0.0, 0.0); // 偏移方向
uniform float offset_strength = 0.1; // 偏移强度
uniform float shrink_strength = 0.5; // 缩小强度
uniform sampler2D add_texture;
uniform sampler2D add_ems_texture;
uniform bool alpha_apply;
void vertex() {
// 顶点位移（使用顶点噪声）
float noiseVal = (texture(noiseVertex, UV + (TIME * speedVertex)).r * 2.0) - 1.0;
vec3 displacement = NORMAL * noiseVal * distortionVertex;
VERTEX += displacement;
// 采样生长纹理（UV2）
float grow_val = texture(grow_texture, UV2).r;
// 对生长值小于0.03的部分进行偏移和缩放
if (grow_val < 0.03) {
float offset_factor = (0.3 - grow_val) / 0.3;
VERTEX.x += offset_direction.x * offset_strength * offset_factor;
VERTEX.y += offset_direction.y * offset_strength * offset_factor;
VERTEX *= (0.8 - shrink_strength * offset_factor);
}
}
void fragment() {
// --- 修改点：将视图空间顶点转换为世界空间，用于噪声采样 ---
vec4 world_pos = INV_VIEW_MATRIX * vec4(VERTEX, 1.0);
// 使用世界空间的 xz 平面作为噪声纹理坐标（可根据需要改为 xy 或 yz）
vec2 uv = world_pos.xz;
// 保留原有的时间动画效果
uv += TIME * 0.5 * offset_direction.xy;
float noise = texture(noise_texture, uv).r;
// 生长纹理处理（基于UV）
vec4 grow_color = texture(grow_texture, UV);
grow_color.r += noise * 0.3;
if (grow_color.r < 0.3) {
grow_color.r -= noise;
if (grow_color.r < 0.01) {
discard;
}
}
// 基础纹理采样
vec4 albedo_color = texture(albedo_texture, UV);
vec4 normal_color = texture(normal_texture, UV);
NORMAL_MAP = normal_color.rgb;
vec4 ems_color = texture(ems_texture, UV);
vec4 add_color = texture(add_texture, UV);
vec4 add_ems = texture(add_ems_texture, UV);
albedo_color *= add_color;
ems_color *= add_ems;
// 根据生长值混合颜色与自发光
ALBEDO = mix(albedo_color.rgb, ems_color.rgb, 1.0 - smoothstep(0.3, 0.4, grow_color.r));
EMISSION = mix(ems_color.rgb * ems, vec3(0.0), smoothstep(0.3, 0.4, grow_color.r));
// 粗糙度
vec4 rou_color = texture(rounghess_texture, UV);
ROUGHNESS = rou_color.r;
if (alpha_apply) {
ALPHA = albedo_color.a;
}
}Live Preview
