This is a Plugin for Godot and is used for create multimesh by mouse draw
Step 1. Open new scene and insert a MeshInstance that must have a StaticBody with collision shape..
Step 2. Download and insert into your project folder the plugin.
Step 3. Going to Project -> Project Settings -> Plugins and activate the plugin, a window will appear in the 3d viewport.
Step 4. Click on Add for add the mesh file .tres (!IMPORTANT MUST HAVE THE NAME INTO MESH->RESOURCE->NAME).
Step 5. Toggle on a Draw checkbutton and press on added button.
Step 6. Draw on 3d viewport by clicking left mouse anywhere on the CollisionShape.
Step 7. In the scene tree you will now find a multimeshinstance among its properties in the inspector you will find the toggle collider (Activate if you want that its collide).
Step 8. Going into window plugin and select brush and finally generate.
Thanks goes to fenix who helped me understand how to make a plugin and also to the STBL project, which is why I made this plugin