update

shaders/012_polygon/polygon.gdshader

@@ -0,0 +1,30 @@
+shader_type spatial;
+render_mode cull_disabled;
+
+vec4 polygon(vec2 uv, float width, int sides)
+{
+	// UV goes from [0 , 1], we multiply by two ( [0, 2] ) and subtract one [ -1, 1]
+	// So the range is centered
+	uv = uv * 2.0 - 1.0;
+
+	// Get the angle from the point to the center, starting with 0 at the middle left side
+	float angle = atan(uv.x, uv.y);
+
+	float radius = TAU / float(sides);
+
+	float dist = cos(floor(0.5 + angle / radius) * radius - angle) * length(uv);
+
+	float poly = step(width, dist);
+
+	return vec4(vec3(poly), 1.0);
+}
+
+void fragment() {
+	// Multiply [0, 1] range of sine to [0, 7]
+	float side_value = 7.0 * sin(TIME);
+
+	// shift the value to half = [3, 10]
+	side_value = side_value + 3.0;
+
+	ALBEDO = vec3(polygon(UV, 0.3, clamp(int(side_value), 3, 9)).rgb);
+}

shaders/012_polygon/polygon.tscn

@@ -0,0 +1,15 @@
+[gd_scene load_steps=4 format=3 uid="uid://2o8nbxn0x7of"]
+
+[ext_resource type="Shader" path="res://shaders/012_polygon/polygon.gdshader" id="1_cwvsg"]
+
+[sub_resource type="ShaderMaterial" id="ShaderMaterial_4pm8x"]
+render_priority = 0
+shader = ExtResource("1_cwvsg")
+
+[sub_resource type="QuadMesh" id="QuadMesh_87u1q"]
+material = SubResource("ShaderMaterial_4pm8x")
+
+[node name="Polygon" type="Node3D"]
+
+[node name="MeshInstance3D" type="MeshInstance3D" parent="."]
+mesh = SubResource("QuadMesh_87u1q")