Level design with Pro Builder

The Unity Editor includes a free basic 3D modelling tool called Pro Builder that is good for blocking out levels without the need of a modelling software. I will teach you the very basics of Pro Builder.

The Pro Builder UI

The main component of Pro Builder is the Pro Builder Window that I docked to the left of the Unity Editor. This panel is context sensitive, meaning that its contents will change depending on what you're working with.

For a description of each tool, press the Shift key while hovering the mouse cursor.

Appended to the top-center part of the Scene viewport are the selection mode buttons of Pro Builder. From left to right, these buttons are:

• Object
  • Select entire objects
• Vertices
  • Select and work with vertices
• Edges
  • Select and work with edges
• Faces
  • Select and work with polygons, or faces

When selecting each of these buttons, the Pro Builder panel will change its contents. When you don't want to edit a 3D model, be sure to have the first button, Object, selected.

To the top-left of the Scene viewport is the Pro Grids window, which is an addon by the same developers of Pro Builder, so they work together very well. When Pro Grids is enable, moving and placing objects becomes grid/based. Objects will snap to a grid, and the size of that grid is defined by the number on top of this window, which is 0.5 currently. You can toggle Pro Grids with the third button from the top, the one that right now says "ON". If you want your levels to have some precision to them, leave Pro Grids enabled.

Basic modelling

Let's begin by deleting the plane GameObject we created previously for the floor of our world. Now, create a plane with Pro Build, by clicking the "+" sign in the New Shape button in the Pro Builder panel.

This will open a new window with some options for the shape you're creating. Select Plane instead of Cube.

Make the Width and Length Segments 0 for now, then press Build.

Close the Shape Tool panel. Now, instead of moving our entire Object, change the selection mode to Faces and select the plane you just created. You'll see that it turns yellow. This indicates that you are selecting a polygon with Pro Builder, instead of a GameObject like you normally do in Unity. Since the plane is made up of only one polygon, it all highlights. Move it to the center of the map.

Let's try making our level have an L shape. Change selection mode to Edges and select an edge.

With the Move tool enabled (hotkey W), hold Shift in your keyboard and move the selected edge to extend the length of your floor. This will perform an extrusion.

Do the same with another edge to get an L shape.

Ahh, what a beautiful L shaped map. Right, now let's make some walls. While staying in Edges selection mode, press the Select Holes button in he Pro Builder panel.

This tool automatically selects all of the border edges. You can also do this manually by holding Shift in your keyboard and left clicking every edge. Now perform an extrusion upwards.

Something nice about Pro Builder is that the default texture can tell us how big something is. Each square in the texture is 1 meter tall and wide. That makes our room 4 meters tall. 3 meters would be the minimum height a room should have in Orchid Rain, to allow the player freer movement. You can of course make smaller rooms. The smallest place the player can fit is a 1 x 1 whole, which could be an air duct. Useful for sneaking around.

Let's make one last modification to our level. We'll add a roof to one of the corners. Select a pair of edges that are in front of each other and press the Bridge Edges button in the Pro Builder panel. You might have to scroll the panel to find that button.

Bridging and extrusion are common 3D modelling operations. By bridging 2 edges we have connected them with a new polygon. To see your roof you can orbit the camera and look from the bottom upwards.

Let's now change our selection mode back to Object to stop modelling. Change the Layer of the environment we've just created to WorldColliders and mark it as Static. Also note that Pro Builder objects come with a Mesh Collider component by default. This is perfect for us, as we would have added it anyway. Never forget to add a Collider to all parts of your environment.

This level geometry is perfectly functional, but you need to re-calculate your NavMesh. It should look something like this:

Now re-arrange your spawners and try the level. You should be seeing something like this.

More on Pro Builder

You should see some of the official Pro Builder tutorials. There are more in-depth guides out there. I'll leave you one video here to get you started, by the very didactic Brackeys.