Fix constant value sliders in material graphs to not be used due to shader compilations

Source/Editor/Surface/Elements/FloatValue.cs

@@ -33,6 +33,10 @@ namespace FlaxEditor.Surface.Elements
             Archetype = archetype;
 
             ParentNode.ValuesChanged += OnNodeValuesChanged;
+
+            // Disable slider if surface doesn't allow it
+            if (!ParentNode.Surface.CanLivePreviewValueChanges)
+                _slideSpeed = 0.0f;
         }
 
         private void OnNodeValuesChanged()

Source/Editor/Surface/MaterialSurface.cs

@@ -22,6 +22,9 @@ namespace FlaxEditor.Surface
         {
         }
 
+        /// <inheritdoc />
+        public override bool CanLivePreviewValueChanges => false;
+
         /// <inheritdoc />
         public override string GetTypeName(ScriptType type)
         {

Source/Editor/Surface/VisjectSurface.cs

@@ -534,6 +534,11 @@ namespace FlaxEditor.Surface
         /// </summary>
         public virtual bool CanSetParameters => false;
 
+        /// <summary>
+        /// Gets a value indicating whether surface supports/allows live previewing graph modifications due to value sliders and color pickers. True by default but disabled for shader surfaces that generate and compile shader source at flight.
+        /// </summary>
+        public virtual bool CanLivePreviewValueChanges => true;
+
         /// <summary>
         /// Determines whether the specified node archetype can be used in the surface.
         /// </summary>