Render heightmap to layer

src/node_slider.h

@@ -9,6 +9,7 @@ public:
     glm::vec2 m_value{0};
     glm::vec2 m_old_value;
     std::function<void(Node* target, float value)> on_value_changed;
+    std::function<void(Node* target, float value)> on_value_final;
     virtual Node* clone_instantiate() const override;
     virtual void clone_copy(Node* dest) const override;
     virtual void init() override;