HeightToNormal Node added for feature request #5

addons/ShaderLib/Procedural/HeightToNormal.gd

@@ -0,0 +1,65 @@
+@tool
+class_name VisualShaderNodeProceduralHeightToNormal extends VisualShaderNodeCustom
+
+func _get_name() -> String:
+	return "HeightToNormal"
+
+func _get_category() -> String:
+	return "Procedural"
+
+func _get_description() -> String:
+	return "Generates a normal map from a height map."
+
+func _get_return_icon_type() -> PortType:
+	return PORT_TYPE_VECTOR_3D
+
+func _get_input_port_count() -> int:
+	return 3
+
+func _get_input_port_name(port: int) -> String:
+	match port:
+		0:
+			return "height map"
+		1:
+			return "uv"
+		2:
+			return "bump strength"
+	return ""
+
+func _get_input_port_type(port: int) -> PortType:
+	match port:
+		0:
+			return PORT_TYPE_SAMPLER
+		1:
+			return PORT_TYPE_VECTOR_2D
+		_:
+			return PORT_TYPE_SCALAR
+
+func _get_input_port_default_value(port: int) -> Variant:
+	match port:
+		2:
+			return 8.0
+		_:
+			return null
+
+func _get_output_port_count() -> int:
+	return 1
+
+func _get_output_port_name(port: int) -> String:
+	return "normal"
+
+func _get_output_port_type(port: int) -> PortType:
+	return PORT_TYPE_VECTOR_3D
+
+func _get_global_code(mode: Shader.Mode) -> String:
+	return "#include \"res://addons/ShaderLib/Procedural/Procedural.gdshaderinc\""
+
+func _get_code(input_vars: Array[String], output_vars: Array[String], mode: Shader.Mode, type: VisualShader.Type) -> String:
+	var uv: String = "UV"
+	if input_vars[1]:
+		uv = input_vars[1]
+
+	var sampler: String = input_vars[0]
+	var bump: String = input_vars[2]
+
+	return output_vars[0] + " = heigth_to_normal(%s, %s, %s);" % [sampler, uv, bump]

addons/ShaderLib/Procedural/Procedural.gdshaderinc

@@ -229,4 +229,19 @@ float rounded_rectangle_shape(vec2 uv, float width, float height, float radius){
 	uv = abs(uv * 2.0 - 1.0) - vec2(width, height) + radius;
 	float dist = length(max(vec2(0.0), uv)) / radius;
 	return clamp((1.0 - dist) / fwidth(dist), 0.0, 1.0);
+}
+
+vec3 heigth_to_normal(sampler2D height_map, vec2 uv, float bump_strength) {
+	float pixel_width = .002;
+	float height = texture(height_map, uv).r;
+	float r = height - texture(height_map, uv + vec2(pixel_width, 0)).r;
+	float l = height - texture(height_map, uv - vec2(pixel_width, 0)).r;
+	float u = height - texture(height_map, uv + vec2(0, pixel_width)).r;
+	float d = height - texture(height_map, uv - vec2(0, pixel_width)).r;
+	float h = (r - l) / pixel_width;
+    float v = (u - d) / pixel_width;
+	vec3 n = vec3(h, v, 1.);
+	n.x = n.x * (pixel_width * bump_strength * .5) + .5;
+	n.y = n.y * (pixel_width * bump_strength * .5) + .5;
+	return normalize(n);
 }

project.godot

@@ -12,5 +12,5 @@ config_version=5
 
 config/name="Godot-shader-lib"
 config/tags=PackedStringArray("addons")
-config/features=PackedStringArray("4.2", "Forward Plus")
+config/features=PackedStringArray("4.3", "Forward Plus")
 config/icon="res://icons/icon.png"