/godot-shaders-basics

Uniforms and built-in variables

Uniform hints

uniform float intensity : hint_range(0.0, 1.0) = 0.5;
uniform vec4 tint_color : source_color = vec4(1.0);
uniform sampler2D noise_texture;

Runtime: material.set_shader_parameter("intensity", 0.8)

canvas_item built-ins

• UV, COLOR, TEXTURE, TIME, SCREEN_UV

spatial built-ins

• ALBEDO, NORMAL, ROUGHNESS, METALLIC

WHY uniforms beat hardcoding

// GOOD — tweakable in inspector
uniform float speed = 1.0;
void fragment() { COLOR.r = sin(TIME * speed); }

// BAD — requires shader recompile to tune
void fragment() { COLOR.r = sin(TIME * 2.5); }

Move invariant math to vertex(); pass via varying.