implemented error notification when not giving an unicode for the icon

lib/network/modules/PhysicsEngine.js

@@ -28,7 +28,7 @@ class PhysicsEngine {
     this.options = {};
     this.defaultOptions = {
       barnesHut: {
-        theta: 0.5, // inverted to save time during calculation
+        theta: 0.5,
         gravitationalConstant: -2000,
         centralGravity: 0.3,
         springLength: 95,

lib/network/modules/components/nodes/shapes/Icon.js

@@ -44,9 +44,8 @@ class Icon extends NodeBase {
 
   _icon(ctx, x, y, selected) {
     let iconSize = Number(this.options.icon.size);
-    let relativeIconSize = iconSize * this.body.view.scale;
 
-    if (this.options.icon.code && relativeIconSize > this.options.scaling.label.drawThreshold - 1) {
+    if (this.options.icon.code !== undefined) {
       ctx.font = (selected ? "bold " : "") + iconSize + "px " + this.options.icon.face;
 
       // draw icon
@@ -62,6 +61,10 @@ class Icon extends NodeBase {
       // disable shadows for other elements.
       this.disableShadow(ctx);
     }
+    else {
+      console.error('When using the icon shape, you need to define the code in the icon options object. This can be done per node or globally.')
+    }
+
   }
 
   distanceToBorder(ctx, angle) {