add support for generating slots from blender properties

Author: marwie

src/utils/parser.js

@@ -370,11 +370,21 @@ function parse(gltf, { fileName = 'model', ...options } = {}) {
     // Bail out if the object was pruned
     if (pruned !== undefined) return pruned
 
+    // Add custom slots if defined in the object's userData. 
+    // E.g. userData: { "slot" : "mySlot" } becomes `{ props.mySlot }`
+    const slot = obj.userData?.slot;
+    const hasSlot = (slot && typeof slot === "string" && slot.length > 0);
+    const hasContent = children.length || hasSlot;
+
+    // Close tag if no children
+    result += `${hasContent ? '>' : '/>'}\n`
+
+    // Add children
+    if (children.length) result += `${children}\n`
+    // Add custom slot
+    if (hasSlot) result += `{props.${slot}}\n`;
     // Close tag
-    result += `${children.length ? '>' : '/>'}\n`
-
-    // Add children and return
-    if (children.length) result += children + `</${type}>`
+    if (hasContent) result += `</${type}>`
     return result
   }