Modeling Objects

Core comes up with lots of 3D models but you might get to the point where you need more assets for your game. As you can’t import external content in Core, the only way to create new 3D models is to combine existing content. Kitbashing is placing various models in a group, changing the position, rotation, and scale of each prop and then customizing the materials to make it look like the object you want to make.

Here is an example of a kitbashed reactor based on the map of the game Among Us by Innersloth.

Kitbashed Reactor made in Core (by caillef)
The reactor in the game Among Us

In the following screenshot, the pieces are moved to show which assets were used to create the reactor. On the right in the Hierarchy, the Tube is selected and it has 4 children. The Cylinder is a Child of the Tube, so the Tube is the Parent. While making kitbashed models, it is really important to keep a clean Hierarchy as it will be easier to create the new asset. Each tube of the reactor is one Cylinder, one Ring – Quarter Thick and two Urban Pipe Cap 03 with specific transform properties and materials that create the illusion of an energy tube. By adding those 4 objects in the Tube group, it is easy to duplicate the tube and place several tubes around the reactor.

Decomposition of the reactor

Groups and Folders


Folders can be used to organize projects according to your individual preferences. They are the best option for putting objects with similar purposes or in similar areas together without having to treat them like a single object.

Folder Example

Creating a Folder

  1. Select the Hierarchy window.
  2. Press Ctrl+N or right click and select New Folder.
  3. Type a name for the folder and press Enter.

Adding Objects to a Folder

To add an object to a folder, drag it onto the folder name until it is highlighted with a blue box around it. Toggling the arrow on the left side of the folder name will open it to display the contents, or close it to hide them.

Creating a Folder with Existing Objects

  1. Select the objects to be added to the folder in the Hierarchy window using Ctrl + left click.
  2. Press Ctrl+N or right click and select New Folder Containing These.
  3. Type a name for the folder and press Enter.
Tip: Use Shift + left click to select all of the objects between the last selected and the one you select next.


Creating a group allows you to unite a collection of 3D objects into a single entity that you can copy and manipulate as one object. With Group Selection Mode enabled, you will always select the whole group when you click on any object that is part of it.

Creating a Group from Existing Objects

  1. Select the objects to be added to the group in the Hierarchy window using Ctrl + left click.
  2. Right click one of the selected objects and click New Group Containing These or use Ctrl+G.
  3. Type a name for the group and press Enter.

Switching between Group and Object Selection Mode

Select Object Mode to select individual objects within the group when clicked or Group Mode to select the entire group when any object within the group is clicked. You can also press C to toggle that option.

Optimize your models

While creating your new asset, try to be efficient in the number of 3D models you are using. Core comes with a simple way to optimize kitbashed assets. Merged Models are a type of group where children assets are optimized by the engine to efficiently render your asset. Using a Merged Model as a parent for your kitbashed asset is almost mandatory to improve the performance of your game.

Warning: avoid using Merged Models for everything as merging all the assets of an entire zone of your game could slow game performance instead of making it more efficient.

Try it in Core! Create a mattress for the bed frame by adding a cube with a custom material as a child to the Craftsman Bed Frame 01.

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