3D on Godot 4 レシピ

Working with 3D Assets

Mon, 01 Jan 0001 00:00:00 +0000

Working with 3D Assets

Detailed recipes for importing and working with 3D assets including models, animations, and materials.

For these examples, we’ll be using the following 3d assets from Kay Lousberg:

In this section:

Basic FPS Character

Mon, 01 Jan 0001 00:00:00 +0000

Problem

You need to make a first-person shooter (FPS) character.

Solution

Start with a CharacterBody3D node, and add a CollisionShape3D to it. The CapsuleShape3D collision shape is the most common choice. Depending on your world setup, you may want to add additional shapes here, but for the purposes of this example, we’ll stick to the basics.

We’ll leave all the sizing at the default values, meaning the capsule will be 2 meters high. Move it up by 1.0 m to align its bottom with the ground.

Camera Gimbal

Mon, 01 Jan 0001 00:00:00 +0000

Tip

This article is being updated from Godot 3 to Godot 4.

Problem

You need a camera controller, using mouse or keyboard, that remains level while rotating and following a target.

Solution

Try this: take a Camera3D node and rotate it a small amount around X (the red ring on the gizmo), then a small amount around Z (the blue ring). Now reverse the X rotation and click the “Preview” button. Observe how the camera is now tilted.

Interpolated Camera

Mon, 01 Jan 0001 00:00:00 +0000

Problem

You need a 3D camera that smoothly follows a target (interpolates).

Solution

Info

Godot’s built-in InterpolatedCamera node is deprecated and will be removed in the release of Godot 4.0.

Attach the script below to a Camera3D node in your scene. The three export properties let you choose:

lerp_speed - the camera’s movement speed. Lower values result in a “lazier” camera.
target - choose the camera’s target node.
offset - position of the camera relative to the target.

See below for some examples of the camera in action.

Shooting with Raycasts

Mon, 01 Jan 0001 00:00:00 +0000

Problem

You need to implement shooting in an FPS, but moving individual projectiles is impractical.

Solution

Game physics engines often break down when trying to handle very fast-moving objects. The solution is to cast a ray from the shooter’s location and detect the first thing that would be hit.

There are two ways to approach raycasting in Godot: the RayCast3D node, or directly casting a ray in space using the physics engine. While they can both accomplish the same thing, each has its uses. The node method tends to be best for situations where you continuously want to check for collisions - a downward-facing ray to check if you’re on the floor, for example.

CharacterBody3D: Movement

Mon, 01 Jan 0001 00:00:00 +0000

Tip

This article is being updated from Godot 3 to Godot 4.

Problem

You need a player-controlled 3D character body.

Solution

For this recipe, we’ll be using this adorable tank model:

You can grab this model on Itch.io: https://gtibo.itch.io/mini-tank or use any other model you’d like. We won’t be doing anything that’s tank-specific here.

In the case of this asset, the download includes an OBJ file, and we’ll find it more convenient if we import it as a scene:

3D Unit Healthbars

Mon, 01 Jan 0001 00:00:00 +0000

Problem

You want a floating “healthbar” for your 3D game objects (mobs, characters, etc.).

Solution

For this solution, we’re going to re-use a 2D healthbar based on a TextureProgressBar node. It’s already set up with textures and code for updating the value and color. If you already have something similar, feel free to use it here. In the example, we’ll name this scene “Healthbar2D”.

If you need some assets, here are the three images used in the bar:

Shooting projectiles

Mon, 01 Jan 0001 00:00:00 +0000

Tip

This article is being updated from Godot 3 to Godot 4.

Problem

You want to shoot projectiles from your player/mob/etc..

Solution

For this example, we’ll use the “Mini Tank” that we set up in CharacterBody3D: Movement.

Setting up the bullet

First, we’ll set up a “bullet” object that we can instance. Here are the nodes we’ll use:

 Area3D: Bullet
 MeshInstance
 CollisionShape

For your mesh, you can use one of Godot’s built-in primitive shapes, or something like this:

Rolling Cube

Mon, 01 Jan 0001 00:00:00 +0000

Problem

You want to make a rolling cube in 3D.

Solution

Rolling a cube is trickier than it seems. You can’t just rotate the cube around its center:

Instead, the cube needs to be rotated around its bottom edge.

Here’s the tricky part: which bottom edge? It depends on which direction the cube is rolling.

In preparing this recipe, I experimented with a few different solutions to this problem:

Align Movement with Camera

Mon, 01 Jan 0001 00:00:00 +0000

Tip

This article is being updated from Godot 3 to Godot 4.

Problem

When moving with WASD-style controls in 3D, it’s easy to get disoriented if the camera rotates. Whose forward counts - the player’s (ie the camera’s) or the object in the game world?

Solution

While this situation can apply to many possible scenarios, we’ll use the Rolling Cube recipe as our example.

In the script for the cube, we have the following code for movement:

Arcade-style Spaceship

Mon, 01 Jan 0001 00:00:00 +0000

Problem

You want to make a 3D spaceship that flies in an arcade/cinematic way. You’re not looking for realistic physics, but more of a dog-fighting, “Star Wars”-style of spaceflight.

Solution

To accomplish this, we’ll use a CharacterBody3D for the ship. The three axis inputs (pitch, roll, and yaw) will rotate the body’s basis around the corresponding axis. The direction of motion will always point forward.

Note

You can do this with RigidBody3D and get the same results. See the example project linked below, which includes a rigid body version as well.

Drawing Vectors in 3D

Mon, 01 Jan 0001 00:00:00 +0000

Tip

This article is being updated from Godot 3 to Godot 4.

Problem

You’d like visual debug information in your 3D game: a way to see vectors representing velocity, position, etc.

Solution

Debug drawing in 2D is quite convenient. CanvasItem provides a range of primitive drawing methods to use in the _draw() callback. In 3D, things are not quite so simple. One solution is to use ImmediateGeometry to manually create meshes, but this is very cumbersome and inconvenient for quick debugging.

Arcade-style Airplane

Mon, 01 Jan 0001 00:00:00 +0000

Problem

You want to make an airplane controller in 3D, but don’t need a fully accurate flight-simulator.

Solution

In this recipe, we’re going to make a simplified airplane controller. By “simplified” we mean stripping things down to the basics. We’re looking for the “feel” of flying a plane - one that you can just jump in and start flying effortlessly, with a minimal control scheme.

Note

This recipe is not an accurate flight simulator. We are not simulating aerodynamics, so this doesn’t fly like a real airplane. We’re going for simplicity and “fun” here, not accuracy.

Arcade-style Car

Mon, 01 Jan 0001 00:00:00 +0000

Tip

This article is being updated from Godot 3 to Godot 4.

Problem

You want to make an arcade-style car game, so you’re looking for simplicity over realistic physics. In this recipe, you’ll learn how to make a fun, driveable car using a rolling sphere.

Solution

There are a lot of ways to make a driving game. Different games need different levels of realism. If you’re trying to make a light, arcade-style car, you don’t need all of the features that Godot’s VehicleBody3D node provides, such as supension, independently modeled wheels, etc.

Click to move

Mon, 01 Jan 0001 00:00:00 +0000

Tip

This article is being updated from Godot 3 to Godot 4.

Problem

You want to move a 3D object to a clicked position.

Solution

We’ll start with a flat plane for our world. Our actor will move on this plane.

The actor for this demo is a triangular prism mesh:

Here is the code for the movement. If given a target, the object will turn and move toward it.

Smooth rotation

Mon, 01 Jan 0001 00:00:00 +0000

Problem

You want to smoothly rotate a 3D object to point in a new direction.

Solution

When you first encounter this problem, you may find yourself thinking in terms of Euler angles - the three values representing the angles to the x/y/z axes. While Godot will allow you to see the object’s Euler angles in the rotation property, it is not recommended to use them to work in 3D. There are a number of reasons why this the case, such as a problem called “gimbal lock”, where you lose one degree of freedom when one of your rotations reaches 90 degrees.

CharacterBody3D: Align with Surface

Mon, 01 Jan 0001 00:00:00 +0000

Problem

You need your character body to align with the surface or terrain.

Solution

This recipe builds on the basic CharacterBody3D controller described in the CharacterBody3D: Movement recipe, so read that one first.

First, we’ve added some terrain to the scene. You can download the terrain from here: https://fertile-soil-productions.itch.io/modular-terrain-pack. This is low-poly terrain, but you can use or make any terrain you like for this technique.

As you can see, the movement still works with the terrain, but the tank seems to “float” above the slopes because it doesn’t change its orientation.

3D Kinematic Car

Wed, 09 Dec 2020 20:23:50 -0700

&nbsp 3D Car

Making a 3D car using CharacterBody3D.