Modding:Advanced Blocks

This page was last verified for Vintage Story version 1.19.3.

This code mod tutorial requires a development environment. If you do not have one, please read and complete the Setting up your Development Environment page. It is also highly recommended to have read and completed the Basic Block tutorial.

Creating a Trampoline

In this tutorial will we create a block with more advanced functionality: a trampoline.

Block Assets

Similar to our Basic Block, the first things we need are the assets of the block. Create a trampoline.json blocktype based on our block created in the other tutorial.

In our blocktype file, we need to add the class property. This property essentially tells our new block to be controlled by a certain C# class.

	class: "trampoline",

We will create this class in our development environment to give the block the desired functionality. You can download the assets of the mod here. All you need to do is to place the contents of this zip file in your assets directory in your development project.

The Block Class

To create our mod, we need a number of new *.cs files in our project.

The Mod System

In order to create a mod, we needs to create a class that extends ModSystem. This will allow use to register all kinds of stuff, but for now we will stick to only registering our block class.

public class TrampolineMod : ModSystem
{
    
}

Now you need to override the Start(ICoreAPI) method and register the class.

The RegisterBlockClass function has two parameters: the first is our block class ID, noteably how we use this class in our blocktype json files. Ensure that this is identical to the class we specified in our earlier asset file. The second parameter is the type of our block class.

public class TrampolineMod : ModSystem
{
    public override void Start(ICoreAPI api)
    {
        base.Start(api);
        api.RegisterBlockClass("trampoline", typeof(TrampolineBlock));
    }
}

This should be marked as a syntax error because there is no TrampolineBlock class yet.

The Block Class

Let's create our block class. When naming block scripts, it is recommended to name them in the format "{Name}Block". In the case of the trampoline, we shall name our script TrampolineBlock.cs. Any block class has to extend Block, giving it the functionality we need to access:

public class TrampolineBlock : Block
{

}

This should solve all syntax errors.

So how do we implement a bouncy block? It's pretty helpful to take a look at the api documentation to find a proper way to implement it.

The method void OnEntityCollide(IWorldAccessor world, Entity entity, BlockPos pos, BlockFacing facing, Vec3d collideSpeed, bool isImpact) seems to be a good way to implement a bouncy functionality. Note that every trampoline block placed in the game will share the same instance of TrampolineBlock. Because that object is shared by multiple blocks, it does not have a field for the block position. That's why the event handler includes the pos parameter.

When should an entity bounce?

1. The entity should bounce in the moment it lands on top of the block and not if it is standing on it already. Therefore, isImpact has to be true.
2. The entity should be colliding vertically. The sides of the block shouldn't push an entity away. So the axis of the facing has to be Y.

How can we make the entity bounce?

In order to make an entity bounce, we need to change its direction. Therefore we can simply revert its motion. The faster the entity will be when during the collision the further it will be pushed away. But simply reverting the motion wouldn't be ideal. The entity would never lose its motion and bounce endless. So let's go for something smaller and make the entity lose 20% of its motion each bounce:

entity.Pos.Motion.Y *= -0.8;

The *= is a shorthand way of writing:

entity.Pos.Motion.Y = entity.Pos.Motion.Y * -0.8;

---

If we put everything together it should look like this:

public class TrampolineBlock : Block
{
    public override void OnEntityCollide(IWorldAccessor world, Entity entity, BlockPos pos, BlockFacing facing, Vec3d collideSpeed, bool isImpact)
    {
        if (isImpact && facing.Axis == EnumAxis.Y)
        {
            entity.Pos.Motion.Y *= -0.8;
        }
    }
}

Although this code works already, some sound effects would be rather nice. We can implement it by adding a sound link field to our block, which can use to play the game:tick sound.

public AssetLocation tickSound = new AssetLocation("game", "tick");

This tickSound will played every time an entity bounces:

world.PlaySoundAt(tickSound, entity.Pos.X, entity.Pos.Y, entity.Pos.Z);

---

If you have done everything right, your file should look similar to this:

using Vintagestory.API.Common;
using Vintagestory.API.Common.Entities;
using Vintagestory.API.MathTools;

namespace VSExampleMods
{
    public class TrampolineMod : ModSystem
    {

        public override void Start(ICoreAPI api)
        {
            base.Start(api);
            api.RegisterBlockClass("trampoline", typeof(TrampolineBlock));
        }
    }

    public class TrampolineBlock : Block
    {
        public AssetLocation tickSound = new AssetLocation("game", "tick");

        public override void OnEntityCollide(IWorldAccessor world, Entity entity, BlockPos pos, BlockFacing facing, Vec3d collideSpeed, bool isImpact)
        {
            if (isImpact && facing.Axis == EnumAxis.Y)
            {
                world.PlaySoundAt(tickSound, entity.Pos.X, entity.Pos.Y, entity.Pos.Z);
                entity.Pos.Motion.Y *= -0.8;
            }
        }
    }
}

Of course you can download the file directly Trampoline.cs.

Testing

Finally we can run our first test. Looks pretty good, right?

Hint: Use the client command .tfedit if you want to adjust the block position, rotation and scale in Hands, in GUI, when dropped on the ground or in third person mode.

Distribution

Using the new Mod Template

If using the mod template setup, follow the instructions on Setting up your Development Environment to pack and distribute your mod.

Using the (old) Modtools

If using the modtools program, open the modtools and type in pack <your mod id>. Now you can take the zip file and share it with other people. It will work in the same way as ordinary mods, you can install it by copying it into the mods folder.

Mod Download

Here is my version:

• for VS v1.9: Trampoline_vs1.9_v1.0.0.zip
• for VS v1.5: Trampoline.zip

Moving Forward

Now that you've successfully made an advanced block you can go even further by learning how to utilize Block Entities and how to create your own Block Behaviors. Both of these tutorials will teach you how to add even more mechanics to your custom blocks.

Or, you can try out making an Advanced Item if you haven't already.

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