Misc shader things

attribution.txt

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+
+Images:
+https://www.freepik.com/free-photo/painted-relief-texture_1037471.htm#query=watercolor%20paper&position=9&from_view=keyword&track=ais
+
+Shaders:
+Watercolor: https://c-chen99.github.io/watercolorShader/final.html
+CMKY: https://www.shadertoy.com/view/MltBW4
+Fresnel: https://godotshaders.com/snippet/fresnel/

godot/shaders/cmky.gdshaderinc

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+// Source: https://www.shadertoy.com/view/MltBW4
+
+vec4 RGBtoCMYK(vec3 rgb) {
+    float K = 1.0 - max(max(rgb.r, rgb.g), rgb.b);
+    return vec4(
+        (1.0 - rgb.r - K) / (1.0 - K),
+        (1.0 - rgb.g - K) / (1.0 - K),
+        (1.0 - rgb.b - K) / (1.0 - K),
+        K
+    );
+}
+
+vec3 CMYKtoRGB(vec4 cmyk) {
+    return vec3(
+        (1.0 - cmyk.x) * (1.0 - cmyk.w),
+		(1.0 - cmyk.y) * (1.0 - cmyk.w),
+		(1.0 - cmyk.z) * (1.0 - cmyk.w)
+    );
+}

godot/shaders/fresnel.gdshaderinc

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+// Source: https://godotshaders.com/snippet/fresnel/
+
+float fresnel(float amount, vec3 normal, vec3 view) {
+	return pow((1.0 - clamp(dot(normalize(normal), normalize(view)), 0.0, 1.0 )), amount);
+}
+
+//void fragment()
+//{
+//	vec3 base_color = vec3(0.0);
+//	float basic_fresnel = fresnel(3.0, NORMAL, VIEW);
+//	ALBEDO = base_color + basic_fresnel;
+//}

godot/shaders/watercolor_frag.tres

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+[gd_resource type="VisualShader" load_steps=3 format=3 uid="uid://dmfe4o4ct2vgh"]
+
+[sub_resource type="VisualShaderNodeExpression" id="VisualShaderNodeExpression_np6v0"]
+output_port_for_preview = 0
+size = Vector2(513, 448.4)
+expression = "out_color = vec3(1.0, 1.0, 1.0);"
+
+[sub_resource type="VisualShaderNodeColorConstant" id="VisualShaderNodeColorConstant_p160o"]
+output_port_for_preview = 0
+constant = Color(0.873209, 6.54578e-06, 0.551742, 1)
+
+[resource]
+code = "shader_type spatial;
+render_mode blend_mix, depth_draw_opaque, cull_back, diffuse_lambert, specular_schlick_ggx;
+
+
+
+
+void fragment() {
+	vec3 n_out2p0;
+// Expression:2
+	n_out2p0 = vec3(0.0, 0.0, 0.0);
+	{
+		n_out2p0 = vec3(1.0, 1.0, 1.0);
+	}
+
+
+// Output:0
+	ALBEDO = n_out2p0;
+
+
+}
+"
+graph_offset = Vector2(-567.36, -225.354)
+nodes/fragment/0/position = Vector2(400, 120)
+nodes/fragment/2/node = SubResource("VisualShaderNodeExpression_np6v0")
+nodes/fragment/2/position = Vector2(-400, -100)
+nodes/fragment/2/size = Vector2(513, 448.4)
+nodes/fragment/2/input_ports = ""
+nodes/fragment/2/output_ports = "0,4,out_color;"
+nodes/fragment/2/expression = "out_color = vec3(1.0, 1.0, 1.0);"
+nodes/fragment/4/node = SubResource("VisualShaderNodeColorConstant_p160o")
+nodes/fragment/4/position = Vector2(-580, 440)
+nodes/fragment/connections = PackedInt32Array(2, 0, 0, 0)

godot/tests/test_watercolor.tscn

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+[gd_scene load_steps=4 format=3 uid="uid://6c8232l2x1jw"]
+
+[ext_resource type="Shader" uid="uid://dmfe4o4ct2vgh" path="res://shaders/watercolor_frag.tres" id="1_kgucu"]
+
+[sub_resource type="ShaderMaterial" id="ShaderMaterial_7kqph"]
+render_priority = 0
+shader = ExtResource("1_kgucu")
+
+[sub_resource type="BoxMesh" id="BoxMesh_ywpec"]
+
+[node name="test_watercolor" type="Node3D"]
+
+[node name="MeshInstance3D" type="MeshInstance3D" parent="."]
+material_override = SubResource("ShaderMaterial_7kqph")
+mesh = SubResource("BoxMesh_ywpec")